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diff --git a/gcc-4.9/gcc/fortran/gfortran.info b/gcc-4.9/gcc/fortran/gfortran.info deleted file mode 100644 index b894d0d0f..000000000 --- a/gcc-4.9/gcc/fortran/gfortran.info +++ /dev/null @@ -1,18449 +0,0 @@ -This is gfortran.info, produced by makeinfo version 5.1 from -gfortran.texi. - -Copyright (C) 1999-2014 Free Software Foundation, Inc. - - Permission is granted to copy, distribute and/or modify this document -under the terms of the GNU Free Documentation License, Version 1.3 or -any later version published by the Free Software Foundation; with the -Invariant Sections being "Funding Free Software", the Front-Cover Texts -being (a) (see below), and with the Back-Cover Texts being (b) (see -below). A copy of the license is included in the section entitled "GNU -Free Documentation License". - - (a) The FSF's Front-Cover Text is: - - A GNU Manual - - (b) The FSF's Back-Cover Text is: - - You have freedom to copy and modify this GNU Manual, like GNU -software. Copies published by the Free Software Foundation raise funds -for GNU development. -INFO-DIR-SECTION Software development -START-INFO-DIR-ENTRY -* gfortran: (gfortran). The GNU Fortran Compiler. -END-INFO-DIR-ENTRY - - This file documents the use and the internals of the GNU Fortran -compiler, ('gfortran'). - - Published by the Free Software Foundation 51 Franklin Street, Fifth -Floor Boston, MA 02110-1301 USA - - Copyright (C) 1999-2014 Free Software Foundation, Inc. - - Permission is granted to copy, distribute and/or modify this document -under the terms of the GNU Free Documentation License, Version 1.3 or -any later version published by the Free Software Foundation; with the -Invariant Sections being "Funding Free Software", the Front-Cover Texts -being (a) (see below), and with the Back-Cover Texts being (b) (see -below). A copy of the license is included in the section entitled "GNU -Free Documentation License". - - (a) The FSF's Front-Cover Text is: - - A GNU Manual - - (b) The FSF's Back-Cover Text is: - - You have freedom to copy and modify this GNU Manual, like GNU -software. Copies published by the Free Software Foundation raise funds -for GNU development. - - -File: gfortran.info, Node: Top, Next: Introduction, Up: (dir) - -Introduction -************ - -This manual documents the use of 'gfortran', the GNU Fortran compiler. -You can find in this manual how to invoke 'gfortran', as well as its -features and incompatibilities. - -* Menu: - -* Introduction:: - -Part I: Invoking GNU Fortran -* Invoking GNU Fortran:: Command options supported by 'gfortran'. -* Runtime:: Influencing runtime behavior with environment variables. - -Part II: Language Reference -* Fortran 2003 and 2008 status:: Fortran 2003 and 2008 features supported by GNU Fortran. -* Compiler Characteristics:: User-visible implementation details. -* Extensions:: Language extensions implemented by GNU Fortran. -* Mixed-Language Programming:: Interoperability with C -* Intrinsic Procedures:: Intrinsic procedures supported by GNU Fortran. -* Intrinsic Modules:: Intrinsic modules supported by GNU Fortran. - -* Contributing:: How you can help. -* Copying:: GNU General Public License says - how you can copy and share GNU Fortran. -* GNU Free Documentation License:: - How you can copy and share this manual. -* Funding:: How to help assure continued work for free software. -* Option Index:: Index of command line options -* Keyword Index:: Index of concepts - - -File: gfortran.info, Node: Introduction, Next: Invoking GNU Fortran, Prev: Top, Up: Top - -1 Introduction -************** - -The GNU Fortran compiler front end was designed initially as a free -replacement for, or alternative to, the Unix 'f95' command; 'gfortran' -is the command you will use to invoke the compiler. - -* Menu: - -* About GNU Fortran:: What you should know about the GNU Fortran compiler. -* GNU Fortran and GCC:: You can compile Fortran, C, or other programs. -* Preprocessing and conditional compilation:: The Fortran preprocessor -* GNU Fortran and G77:: Why we chose to start from scratch. -* Project Status:: Status of GNU Fortran, roadmap, proposed extensions. -* Standards:: Standards supported by GNU Fortran. - - -File: gfortran.info, Node: About GNU Fortran, Next: GNU Fortran and GCC, Up: Introduction - -1.1 About GNU Fortran -===================== - -The GNU Fortran compiler supports the Fortran 77, 90 and 95 standards -completely, parts of the Fortran 2003 and Fortran 2008 standards, and -several vendor extensions. The development goal is to provide the -following features: - - * Read a user's program, stored in a file and containing instructions - written in Fortran 77, Fortran 90, Fortran 95, Fortran 2003 or - Fortran 2008. This file contains "source code". - - * Translate the user's program into instructions a computer can carry - out more quickly than it takes to translate the instructions in the - first place. The result after compilation of a program is "machine - code", code designed to be efficiently translated and processed by - a machine such as your computer. Humans usually are not as good - writing machine code as they are at writing Fortran (or C++, Ada, - or Java), because it is easy to make tiny mistakes writing machine - code. - - * Provide the user with information about the reasons why the - compiler is unable to create a binary from the source code. - Usually this will be the case if the source code is flawed. The - Fortran 90 standard requires that the compiler can point out - mistakes to the user. An incorrect usage of the language causes an - "error message". - - The compiler will also attempt to diagnose cases where the user's - program contains a correct usage of the language, but instructs the - computer to do something questionable. This kind of diagnostics - message is called a "warning message". - - * Provide optional information about the translation passes from the - source code to machine code. This can help a user of the compiler - to find the cause of certain bugs which may not be obvious in the - source code, but may be more easily found at a lower level compiler - output. It also helps developers to find bugs in the compiler - itself. - - * Provide information in the generated machine code that can make it - easier to find bugs in the program (using a debugging tool, called - a "debugger", such as the GNU Debugger 'gdb'). - - * Locate and gather machine code already generated to perform actions - requested by statements in the user's program. This machine code - is organized into "modules" and is located and "linked" to the user - program. - - The GNU Fortran compiler consists of several components: - - * A version of the 'gcc' command (which also might be installed as - the system's 'cc' command) that also understands and accepts - Fortran source code. The 'gcc' command is the "driver" program for - all the languages in the GNU Compiler Collection (GCC); With 'gcc', - you can compile the source code of any language for which a front - end is available in GCC. - - * The 'gfortran' command itself, which also might be installed as the - system's 'f95' command. 'gfortran' is just another driver program, - but specifically for the Fortran compiler only. The difference - with 'gcc' is that 'gfortran' will automatically link the correct - libraries to your program. - - * A collection of run-time libraries. These libraries contain the - machine code needed to support capabilities of the Fortran language - that are not directly provided by the machine code generated by the - 'gfortran' compilation phase, such as intrinsic functions and - subroutines, and routines for interaction with files and the - operating system. - - * The Fortran compiler itself, ('f951'). This is the GNU Fortran - parser and code generator, linked to and interfaced with the GCC - backend library. 'f951' "translates" the source code to assembler - code. You would typically not use this program directly; instead, - the 'gcc' or 'gfortran' driver programs will call it for you. - - -File: gfortran.info, Node: GNU Fortran and GCC, Next: Preprocessing and conditional compilation, Prev: About GNU Fortran, Up: Introduction - -1.2 GNU Fortran and GCC -======================= - -GNU Fortran is a part of GCC, the "GNU Compiler Collection". GCC -consists of a collection of front ends for various languages, which -translate the source code into a language-independent form called -"GENERIC". This is then processed by a common middle end which provides -optimization, and then passed to one of a collection of back ends which -generate code for different computer architectures and operating -systems. - - Functionally, this is implemented with a driver program ('gcc') which -provides the command-line interface for the compiler. It calls the -relevant compiler front-end program (e.g., 'f951' for Fortran) for each -file in the source code, and then calls the assembler and linker as -appropriate to produce the compiled output. In a copy of GCC which has -been compiled with Fortran language support enabled, 'gcc' will -recognize files with '.f', '.for', '.ftn', '.f90', '.f95', '.f03' and -'.f08' extensions as Fortran source code, and compile it accordingly. A -'gfortran' driver program is also provided, which is identical to 'gcc' -except that it automatically links the Fortran runtime libraries into -the compiled program. - - Source files with '.f', '.for', '.fpp', '.ftn', '.F', '.FOR', '.FPP', -and '.FTN' extensions are treated as fixed form. Source files with -'.f90', '.f95', '.f03', '.f08', '.F90', '.F95', '.F03' and '.F08' -extensions are treated as free form. The capitalized versions of either -form are run through preprocessing. Source files with the lower case -'.fpp' extension are also run through preprocessing. - - This manual specifically documents the Fortran front end, which -handles the programming language's syntax and semantics. The aspects of -GCC which relate to the optimization passes and the back-end code -generation are documented in the GCC manual; see *note Introduction: -(gcc)Top. The two manuals together provide a complete reference for the -GNU Fortran compiler. - - -File: gfortran.info, Node: Preprocessing and conditional compilation, Next: GNU Fortran and G77, Prev: GNU Fortran and GCC, Up: Introduction - -1.3 Preprocessing and conditional compilation -============================================= - -Many Fortran compilers including GNU Fortran allow passing the source -code through a C preprocessor (CPP; sometimes also called the Fortran -preprocessor, FPP) to allow for conditional compilation. In the case of -GNU Fortran, this is the GNU C Preprocessor in the traditional mode. On -systems with case-preserving file names, the preprocessor is -automatically invoked if the filename extension is '.F', '.FOR', '.FTN', -'.fpp', '.FPP', '.F90', '.F95', '.F03' or '.F08'. To manually invoke -the preprocessor on any file, use '-cpp', to disable preprocessing on -files where the preprocessor is run automatically, use '-nocpp'. - - If a preprocessed file includes another file with the Fortran -'INCLUDE' statement, the included file is not preprocessed. To -preprocess included files, use the equivalent preprocessor statement -'#include'. - - If GNU Fortran invokes the preprocessor, '__GFORTRAN__' is defined -and '__GNUC__', '__GNUC_MINOR__' and '__GNUC_PATCHLEVEL__' can be used -to determine the version of the compiler. See *note Overview: (cpp)Top. -for details. - - While CPP is the de-facto standard for preprocessing Fortran code, -Part 3 of the Fortran 95 standard (ISO/IEC 1539-3:1998) defines -Conditional Compilation, which is not widely used and not directly -supported by the GNU Fortran compiler. You can use the program coco to -preprocess such files (<http://www.daniellnagle.com/coco.html>). - - -File: gfortran.info, Node: GNU Fortran and G77, Next: Project Status, Prev: Preprocessing and conditional compilation, Up: Introduction - -1.4 GNU Fortran and G77 -======================= - -The GNU Fortran compiler is the successor to 'g77', the Fortran 77 front -end included in GCC prior to version 4. It is an entirely new program -that has been designed to provide Fortran 95 support and extensibility -for future Fortran language standards, as well as providing backwards -compatibility for Fortran 77 and nearly all of the GNU language -extensions supported by 'g77'. - - -File: gfortran.info, Node: Project Status, Next: Standards, Prev: GNU Fortran and G77, Up: Introduction - -1.5 Project Status -================== - - As soon as 'gfortran' can parse all of the statements correctly, it - will be in the "larva" state. When we generate code, the "puppa" - state. When 'gfortran' is done, we'll see if it will be a - beautiful butterfly, or just a big bug.... - - -Andy Vaught, April 2000 - - The start of the GNU Fortran 95 project was announced on the GCC -homepage in March 18, 2000 (even though Andy had already been working on -it for a while, of course). - - The GNU Fortran compiler is able to compile nearly all -standard-compliant Fortran 95, Fortran 90, and Fortran 77 programs, -including a number of standard and non-standard extensions, and can be -used on real-world programs. In particular, the supported extensions -include OpenMP, Cray-style pointers, and several Fortran 2003 and -Fortran 2008 features, including TR 15581. However, it is still under -development and has a few remaining rough edges. - - At present, the GNU Fortran compiler passes the NIST Fortran 77 Test -Suite (http://www.fortran-2000.com/ArnaudRecipes/fcvs21_f95.html), and -produces acceptable results on the LAPACK Test Suite -(http://www.netlib.org/lapack/faq.html#1.21). It also provides -respectable performance on the Polyhedron Fortran compiler benchmarks -(http://www.polyhedron.com/pb05.html) and the Livermore Fortran Kernels -test (http://www.llnl.gov/asci_benchmarks/asci/limited/lfk/README.html). -It has been used to compile a number of large real-world programs, -including the HIRLAM weather-forecasting code -(http://mysite.verizon.net/serveall/moene.pdf) and the Tonto quantum -chemistry package (http://www.theochem.uwa.edu.au/tonto/); see -<http://gcc.gnu.org/wiki/GfortranApps> for an extended list. - - Among other things, the GNU Fortran compiler is intended as a -replacement for G77. At this point, nearly all programs that could be -compiled with G77 can be compiled with GNU Fortran, although there are a -few minor known regressions. - - The primary work remaining to be done on GNU Fortran falls into three -categories: bug fixing (primarily regarding the treatment of invalid -code and providing useful error messages), improving the compiler -optimizations and the performance of compiled code, and extending the -compiler to support future standards--in particular, Fortran 2003 and -Fortran 2008. - - -File: gfortran.info, Node: Standards, Prev: Project Status, Up: Introduction - -1.6 Standards -============= - -* Menu: - -* Varying Length Character Strings:: - -The GNU Fortran compiler implements ISO/IEC 1539:1997 (Fortran 95). As -such, it can also compile essentially all standard-compliant Fortran 90 -and Fortran 77 programs. It also supports the ISO/IEC TR-15581 -enhancements to allocatable arrays. - - GNU Fortran also have a partial support for ISO/IEC 1539-1:2004 -(Fortran 2003), ISO/IEC 1539-1:2010 (Fortran 2008), the Technical -Specification 'Further Interoperability of Fortran with C' (ISO/IEC TS -29113:2012). Full support of those standards and future Fortran -standards is planned. The current status of the support is can be found -in the *note Fortran 2003 status::, *note Fortran 2008 status:: and -*note TS 29113 status:: sections of the documentation. - - Additionally, the GNU Fortran compilers supports the OpenMP -specification (version 3.1, -<http://openmp.org/wp/openmp-specifications/>). - - -File: gfortran.info, Node: Varying Length Character Strings, Up: Standards - -1.6.1 Varying Length Character Strings --------------------------------------- - -The Fortran 95 standard specifies in Part 2 (ISO/IEC 1539-2:2000) -varying length character strings. While GNU Fortran currently does not -support such strings directly, there exist two Fortran implementations -for them, which work with GNU Fortran. They can be found at -<http://www.fortran.com/iso_varying_string.f95> and at -<ftp://ftp.nag.co.uk/sc22wg5/ISO_VARYING_STRING/>. - - Deferred-length character strings of Fortran 2003 supports part of -the features of 'ISO_VARYING_STRING' and should be considered as -replacement. (Namely, allocatable or pointers of the type -'character(len=:)'.) - - -File: gfortran.info, Node: Invoking GNU Fortran, Next: Runtime, Prev: Introduction, Up: Top - -2 GNU Fortran Command Options -***************************** - -The 'gfortran' command supports all the options supported by the 'gcc' -command. Only options specific to GNU Fortran are documented here. - - *Note GCC Command Options: (gcc)Invoking GCC, for information on the -non-Fortran-specific aspects of the 'gcc' command (and, therefore, the -'gfortran' command). - - All GCC and GNU Fortran options are accepted both by 'gfortran' and -by 'gcc' (as well as any other drivers built at the same time, such as -'g++'), since adding GNU Fortran to the GCC distribution enables -acceptance of GNU Fortran options by all of the relevant drivers. - - In some cases, options have positive and negative forms; the negative -form of '-ffoo' would be '-fno-foo'. This manual documents only one of -these two forms, whichever one is not the default. - -* Menu: - -* Option Summary:: Brief list of all 'gfortran' options, - without explanations. -* Fortran Dialect Options:: Controlling the variant of Fortran language - compiled. -* Preprocessing Options:: Enable and customize preprocessing. -* Error and Warning Options:: How picky should the compiler be? -* Debugging Options:: Symbol tables, measurements, and debugging dumps. -* Directory Options:: Where to find module files -* Link Options :: Influencing the linking step -* Runtime Options:: Influencing runtime behavior -* Code Gen Options:: Specifying conventions for function calls, data layout - and register usage. -* Environment Variables:: Environment variables that affect 'gfortran'. - - -File: gfortran.info, Node: Option Summary, Next: Fortran Dialect Options, Up: Invoking GNU Fortran - -2.1 Option summary -================== - -Here is a summary of all the options specific to GNU Fortran, grouped by -type. Explanations are in the following sections. - -_Fortran Language Options_ - *Note Options controlling Fortran dialect: Fortran Dialect Options. - -fall-intrinsics -fbackslash -fcray-pointer -fd-lines-as-code - -fd-lines-as-comments -fdefault-double-8 -fdefault-integer-8 - -fdefault-real-8 -fdollar-ok -ffixed-line-length-N - -ffixed-line-length-none -ffree-form -ffree-line-length-N - -ffree-line-length-none -fimplicit-none -finteger-4-integer-8 - -fmax-identifier-length -fmodule-private -fno-fixed-form -fno-range-check - -fopenmp -freal-4-real-10 -freal-4-real-16 -freal-4-real-8 - -freal-8-real-10 -freal-8-real-16 -freal-8-real-4 -std=STD - -_Preprocessing Options_ - *Note Enable and customize preprocessing: Preprocessing Options. - -A-QUESTION[=ANSWER] - -AQUESTION=ANSWER -C -CC -DMACRO[=DEFN] - -H -P - -UMACRO -cpp -dD -dI -dM -dN -dU -fworking-directory - -imultilib DIR - -iprefix FILE -iquote -isysroot DIR -isystem DIR -nocpp - -nostdinc - -undef - -_Error and Warning Options_ - *Note Options to request or suppress errors and warnings: Error and - Warning Options. - -Waliasing -Wall -Wampersand -Warray-bounds - -Wc-binding-type -Wcharacter-truncation - -Wconversion -Wfunction-elimination -Wimplicit-interface - -Wimplicit-procedure -Wintrinsic-shadow -Wintrinsics-std - -Wline-truncation -Wno-align-commons -Wno-tabs -Wreal-q-constant - -Wsurprising -Wunderflow -Wunused-parameter -Wrealloc-lhs -Wrealloc-lhs-all - -Wtarget-lifetime -fmax-errors=N -fsyntax-only -pedantic -pedantic-errors - -_Debugging Options_ - *Note Options for debugging your program or GNU Fortran: Debugging - Options. - -fbacktrace -fdump-fortran-optimized -fdump-fortran-original - -fdump-parse-tree -ffpe-trap=LIST -ffpe-summary=LIST - -_Directory Options_ - *Note Options for directory search: Directory Options. - -IDIR -JDIR -fintrinsic-modules-path DIR - -_Link Options_ - *Note Options for influencing the linking step: Link Options. - -static-libgfortran - -_Runtime Options_ - *Note Options for influencing runtime behavior: Runtime Options. - -fconvert=CONVERSION -fmax-subrecord-length=LENGTH - -frecord-marker=LENGTH -fsign-zero - -_Code Generation Options_ - *Note Options for code generation conventions: Code Gen Options. - -faggressive-function-elimination -fblas-matmul-limit=N - -fbounds-check -fcheck-array-temporaries - -fcheck=<ALL|ARRAY-TEMPS|BOUNDS|DO|MEM|POINTER|RECURSION> - -fcoarray=<NONE|SINGLE|LIB> -fexternal-blas -ff2c - -ffrontend-optimize - -finit-character=N -finit-integer=N -finit-local-zero - -finit-logical=<TRUE|FALSE> - -finit-real=<ZERO|INF|-INF|NAN|SNAN> - -fmax-array-constructor=N -fmax-stack-var-size=N - -fno-align-commons - -fno-automatic -fno-protect-parens -fno-underscoring - -fsecond-underscore -fpack-derived -frealloc-lhs -frecursive - -frepack-arrays -fshort-enums -fstack-arrays - - -File: gfortran.info, Node: Fortran Dialect Options, Next: Preprocessing Options, Prev: Option Summary, Up: Invoking GNU Fortran - -2.2 Options controlling Fortran dialect -======================================= - -The following options control the details of the Fortran dialect -accepted by the compiler: - -'-ffree-form' -'-ffixed-form' - Specify the layout used by the source file. The free form layout - was introduced in Fortran 90. Fixed form was traditionally used in - older Fortran programs. When neither option is specified, the - source form is determined by the file extension. - -'-fall-intrinsics' - This option causes all intrinsic procedures (including the - GNU-specific extensions) to be accepted. This can be useful with - '-std=f95' to force standard-compliance but get access to the full - range of intrinsics available with 'gfortran'. As a consequence, - '-Wintrinsics-std' will be ignored and no user-defined procedure - with the same name as any intrinsic will be called except when it - is explicitly declared 'EXTERNAL'. - -'-fd-lines-as-code' -'-fd-lines-as-comments' - Enable special treatment for lines beginning with 'd' or 'D' in - fixed form sources. If the '-fd-lines-as-code' option is given - they are treated as if the first column contained a blank. If the - '-fd-lines-as-comments' option is given, they are treated as - comment lines. - -'-fdollar-ok' - Allow '$' as a valid non-first character in a symbol name. Symbols - that start with '$' are rejected since it is unclear which rules to - apply to implicit typing as different vendors implement different - rules. Using '$' in 'IMPLICIT' statements is also rejected. - -'-fbackslash' - Change the interpretation of backslashes in string literals from a - single backslash character to "C-style" escape characters. The - following combinations are expanded '\a', '\b', '\f', '\n', '\r', - '\t', '\v', '\\', and '\0' to the ASCII characters alert, - backspace, form feed, newline, carriage return, horizontal tab, - vertical tab, backslash, and NUL, respectively. Additionally, - '\x'NN, '\u'NNNN and '\U'NNNNNNNN (where each N is a hexadecimal - digit) are translated into the Unicode characters corresponding to - the specified code points. All other combinations of a character - preceded by \ are unexpanded. - -'-fmodule-private' - Set the default accessibility of module entities to 'PRIVATE'. - Use-associated entities will not be accessible unless they are - explicitly declared as 'PUBLIC'. - -'-ffixed-line-length-N' - Set column after which characters are ignored in typical fixed-form - lines in the source file, and through which spaces are assumed (as - if padded to that length) after the ends of short fixed-form lines. - - Popular values for N include 72 (the standard and the default), 80 - (card image), and 132 (corresponding to "extended-source" options - in some popular compilers). N may also be 'none', meaning that the - entire line is meaningful and that continued character constants - never have implicit spaces appended to them to fill out the line. - '-ffixed-line-length-0' means the same thing as - '-ffixed-line-length-none'. - -'-ffree-line-length-N' - Set column after which characters are ignored in typical free-form - lines in the source file. The default value is 132. N may be - 'none', meaning that the entire line is meaningful. - '-ffree-line-length-0' means the same thing as - '-ffree-line-length-none'. - -'-fmax-identifier-length=N' - Specify the maximum allowed identifier length. Typical values are - 31 (Fortran 95) and 63 (Fortran 2003 and Fortran 2008). - -'-fimplicit-none' - Specify that no implicit typing is allowed, unless overridden by - explicit 'IMPLICIT' statements. This is the equivalent of adding - 'implicit none' to the start of every procedure. - -'-fcray-pointer' - Enable the Cray pointer extension, which provides C-like pointer - functionality. - -'-fopenmp' - Enable the OpenMP extensions. This includes OpenMP '!$omp' - directives in free form and 'c$omp', '*$omp' and '!$omp' directives - in fixed form, '!$' conditional compilation sentinels in free form - and 'c$', '*$' and '!$' sentinels in fixed form, and when linking - arranges for the OpenMP runtime library to be linked in. The - option '-fopenmp' implies '-frecursive'. - -'-fno-range-check' - Disable range checking on results of simplification of constant - expressions during compilation. For example, GNU Fortran will give - an error at compile time when simplifying 'a = 1. / 0'. With this - option, no error will be given and 'a' will be assigned the value - '+Infinity'. If an expression evaluates to a value outside of the - relevant range of ['-HUGE()':'HUGE()'], then the expression will be - replaced by '-Inf' or '+Inf' as appropriate. Similarly, 'DATA - i/Z'FFFFFFFF'/' will result in an integer overflow on most systems, - but with '-fno-range-check' the value will "wrap around" and 'i' - will be initialized to -1 instead. - -'-fdefault-integer-8' - Set the default integer and logical types to an 8 byte wide type. - This option also affects the kind of integer constants like '42'. - Unlike '-finteger-4-integer-8', it does not promote variables with - explicit kind declaration. - -'-fdefault-real-8' - Set the default real type to an 8 byte wide type. This option also - affects the kind of non-double real constants like '1.0', and does - promote the default width of 'DOUBLE PRECISION' to 16 bytes if - possible, unless '-fdefault-double-8' is given, too. Unlike - '-freal-4-real-8', it does not promote variables with explicit kind - declaration. - -'-fdefault-double-8' - Set the 'DOUBLE PRECISION' type to an 8 byte wide type. Do nothing - if this is already the default. If '-fdefault-real-8' is given, - 'DOUBLE PRECISION' would instead be promoted to 16 bytes if - possible, and '-fdefault-double-8' can be used to prevent this. - The kind of real constants like '1.d0' will not be changed by - '-fdefault-real-8' though, so also '-fdefault-double-8' does not - affect it. - -'-finteger-4-integer-8' - Promote all 'INTEGER(KIND=4)' entities to an 'INTEGER(KIND=8)' - entities. If 'KIND=8' is unavailable, then an error will be - issued. This option should be used with care and may not be - suitable for your codes. Areas of possible concern include calls - to external procedures, alignment in 'EQUIVALENCE' and/or 'COMMON', - generic interfaces, BOZ literal constant conversion, and I/O. - Inspection of the intermediate representation of the translated - Fortran code, produced by '-fdump-tree-original', is suggested. - -'-freal-4-real-8' -'-freal-4-real-10' -'-freal-4-real-16' -'-freal-8-real-4' -'-freal-8-real-10' -'-freal-8-real-16' - Promote all 'REAL(KIND=M)' entities to 'REAL(KIND=N)' entities. If - 'REAL(KIND=N)' is unavailable, then an error will be issued. All - other real kind types are unaffected by this option. These options - should be used with care and may not be suitable for your codes. - Areas of possible concern include calls to external procedures, - alignment in 'EQUIVALENCE' and/or 'COMMON', generic interfaces, BOZ - literal constant conversion, and I/O. Inspection of the - intermediate representation of the translated Fortran code, - produced by '-fdump-tree-original', is suggested. - -'-std=STD' - Specify the standard to which the program is expected to conform, - which may be one of 'f95', 'f2003', 'f2008', 'gnu', or 'legacy'. - The default value for STD is 'gnu', which specifies a superset of - the Fortran 95 standard that includes all of the extensions - supported by GNU Fortran, although warnings will be given for - obsolete extensions not recommended for use in new code. The - 'legacy' value is equivalent but without the warnings for obsolete - extensions, and may be useful for old non-standard programs. The - 'f95', 'f2003' and 'f2008' values specify strict conformance to the - Fortran 95, Fortran 2003 and Fortran 2008 standards, respectively; - errors are given for all extensions beyond the relevant language - standard, and warnings are given for the Fortran 77 features that - are permitted but obsolescent in later standards. '-std=f2008ts' - allows the Fortran 2008 standard including the additions of the - Technical Specification (TS) 29113 on Further Interoperability of - Fortran with C. - - -File: gfortran.info, Node: Preprocessing Options, Next: Error and Warning Options, Prev: Fortran Dialect Options, Up: Invoking GNU Fortran - -2.3 Enable and customize preprocessing -====================================== - -Preprocessor related options. See section *note Preprocessing and -conditional compilation:: for more detailed information on preprocessing -in 'gfortran'. - -'-cpp' -'-nocpp' - Enable preprocessing. The preprocessor is automatically invoked if - the file extension is '.fpp', '.FPP', '.F', '.FOR', '.FTN', '.F90', - '.F95', '.F03' or '.F08'. Use this option to manually enable - preprocessing of any kind of Fortran file. - - To disable preprocessing of files with any of the above listed - extensions, use the negative form: '-nocpp'. - - The preprocessor is run in traditional mode. Any restrictions of - the file-format, especially the limits on line length, apply for - preprocessed output as well, so it might be advisable to use the - '-ffree-line-length-none' or '-ffixed-line-length-none' options. - -'-dM' - Instead of the normal output, generate a list of ''#define'' - directives for all the macros defined during the execution of the - preprocessor, including predefined macros. This gives you a way of - finding out what is predefined in your version of the preprocessor. - Assuming you have no file 'foo.f90', the command - touch foo.f90; gfortran -cpp -E -dM foo.f90 - will show all the predefined macros. - -'-dD' - Like '-dM' except in two respects: it does not include the - predefined macros, and it outputs both the '#define' directives and - the result of preprocessing. Both kinds of output go to the - standard output file. - -'-dN' - Like '-dD', but emit only the macro names, not their expansions. - -'-dU' - Like 'dD' except that only macros that are expanded, or whose - definedness is tested in preprocessor directives, are output; the - output is delayed until the use or test of the macro; and - ''#undef'' directives are also output for macros tested but - undefined at the time. - -'-dI' - Output ''#include'' directives in addition to the result of - preprocessing. - -'-fworking-directory' - Enable generation of linemarkers in the preprocessor output that - will let the compiler know the current working directory at the - time of preprocessing. When this option is enabled, the - preprocessor will emit, after the initial linemarker, a second - linemarker with the current working directory followed by two - slashes. GCC will use this directory, when it is present in the - preprocessed input, as the directory emitted as the current working - directory in some debugging information formats. This option is - implicitly enabled if debugging information is enabled, but this - can be inhibited with the negated form '-fno-working-directory'. - If the '-P' flag is present in the command line, this option has no - effect, since no '#line' directives are emitted whatsoever. - -'-idirafter DIR' - Search DIR for include files, but do it after all directories - specified with '-I' and the standard system directories have been - exhausted. DIR is treated as a system include directory. If dir - begins with '=', then the '=' will be replaced by the sysroot - prefix; see '--sysroot' and '-isysroot'. - -'-imultilib DIR' - Use DIR as a subdirectory of the directory containing - target-specific C++ headers. - -'-iprefix PREFIX' - Specify PREFIX as the prefix for subsequent '-iwithprefix' options. - If the PREFIX represents a directory, you should include the final - ''/''. - -'-isysroot DIR' - This option is like the '--sysroot' option, but applies only to - header files. See the '--sysroot' option for more information. - -'-iquote DIR' - Search DIR only for header files requested with '#include "file"'; - they are not searched for '#include <file>', before all directories - specified by '-I' and before the standard system directories. If - DIR begins with '=', then the '=' will be replaced by the sysroot - prefix; see '--sysroot' and '-isysroot'. - -'-isystem DIR' - Search DIR for header files, after all directories specified by - '-I' but before the standard system directories. Mark it as a - system directory, so that it gets the same special treatment as is - applied to the standard system directories. If DIR begins with - '=', then the '=' will be replaced by the sysroot prefix; see - '--sysroot' and '-isysroot'. - -'-nostdinc' - Do not search the standard system directories for header files. - Only the directories you have specified with '-I' options (and the - directory of the current file, if appropriate) are searched. - -'-undef' - Do not predefine any system-specific or GCC-specific macros. The - standard predefined macros remain defined. - -'-APREDICATE=ANSWER' - Make an assertion with the predicate PREDICATE and answer ANSWER. - This form is preferred to the older form -A predicate(answer), - which is still supported, because it does not use shell special - characters. - -'-A-PREDICATE=ANSWER' - Cancel an assertion with the predicate PREDICATE and answer ANSWER. - -'-C' - Do not discard comments. All comments are passed through to the - output file, except for comments in processed directives, which are - deleted along with the directive. - - You should be prepared for side effects when using '-C'; it causes - the preprocessor to treat comments as tokens in their own right. - For example, comments appearing at the start of what would be a - directive line have the effect of turning that line into an - ordinary source line, since the first token on the line is no - longer a ''#''. - - Warning: this currently handles C-Style comments only. The - preprocessor does not yet recognize Fortran-style comments. - -'-CC' - Do not discard comments, including during macro expansion. This is - like '-C', except that comments contained within macros are also - passed through to the output file where the macro is expanded. - - In addition to the side-effects of the '-C' option, the '-CC' - option causes all C++-style comments inside a macro to be converted - to C-style comments. This is to prevent later use of that macro - from inadvertently commenting out the remainder of the source line. - The '-CC' option is generally used to support lint comments. - - Warning: this currently handles C- and C++-Style comments only. - The preprocessor does not yet recognize Fortran-style comments. - -'-DNAME' - Predefine name as a macro, with definition '1'. - -'-DNAME=DEFINITION' - The contents of DEFINITION are tokenized and processed as if they - appeared during translation phase three in a ''#define'' directive. - In particular, the definition will be truncated by embedded newline - characters. - - If you are invoking the preprocessor from a shell or shell-like - program you may need to use the shell's quoting syntax to protect - characters such as spaces that have a meaning in the shell syntax. - - If you wish to define a function-like macro on the command line, - write its argument list with surrounding parentheses before the - equals sign (if any). Parentheses are meaningful to most shells, - so you will need to quote the option. With sh and csh, - '-D'name(args...)=definition'' works. - - '-D' and '-U' options are processed in the order they are given on - the command line. All -imacros file and -include file options are - processed after all -D and -U options. - -'-H' - Print the name of each header file used, in addition to other - normal activities. Each name is indented to show how deep in the - ''#include'' stack it is. - -'-P' - Inhibit generation of linemarkers in the output from the - preprocessor. This might be useful when running the preprocessor - on something that is not C code, and will be sent to a program - which might be confused by the linemarkers. - -'-UNAME' - Cancel any previous definition of NAME, either built in or provided - with a '-D' option. - - -File: gfortran.info, Node: Error and Warning Options, Next: Debugging Options, Prev: Preprocessing Options, Up: Invoking GNU Fortran - -2.4 Options to request or suppress errors and warnings -====================================================== - -Errors are diagnostic messages that report that the GNU Fortran compiler -cannot compile the relevant piece of source code. The compiler will -continue to process the program in an attempt to report further errors -to aid in debugging, but will not produce any compiled output. - - Warnings are diagnostic messages that report constructions which are -not inherently erroneous but which are risky or suggest there is likely -to be a bug in the program. Unless '-Werror' is specified, they do not -prevent compilation of the program. - - You can request many specific warnings with options beginning '-W', -for example '-Wimplicit' to request warnings on implicit declarations. -Each of these specific warning options also has a negative form -beginning '-Wno-' to turn off warnings; for example, '-Wno-implicit'. -This manual lists only one of the two forms, whichever is not the -default. - - These options control the amount and kinds of errors and warnings -produced by GNU Fortran: - -'-fmax-errors=N' - Limits the maximum number of error messages to N, at which point - GNU Fortran bails out rather than attempting to continue processing - the source code. If N is 0, there is no limit on the number of - error messages produced. - -'-fsyntax-only' - Check the code for syntax errors, but do not actually compile it. - This will generate module files for each module present in the - code, but no other output file. - -'-pedantic' - Issue warnings for uses of extensions to Fortran 95. '-pedantic' - also applies to C-language constructs where they occur in GNU - Fortran source files, such as use of '\e' in a character constant - within a directive like '#include'. - - Valid Fortran 95 programs should compile properly with or without - this option. However, without this option, certain GNU extensions - and traditional Fortran features are supported as well. With this - option, many of them are rejected. - - Some users try to use '-pedantic' to check programs for - conformance. They soon find that it does not do quite what they - want--it finds some nonstandard practices, but not all. However, - improvements to GNU Fortran in this area are welcome. - - This should be used in conjunction with '-std=f95', '-std=f2003' or - '-std=f2008'. - -'-pedantic-errors' - Like '-pedantic', except that errors are produced rather than - warnings. - -'-Wall' - Enables commonly used warning options pertaining to usage that we - recommend avoiding and that we believe are easy to avoid. This - currently includes '-Waliasing', '-Wampersand', '-Wconversion', - '-Wsurprising', '-Wc-binding-type', '-Wintrinsics-std', - '-Wno-tabs', '-Wintrinsic-shadow', '-Wline-truncation', - '-Wtarget-lifetime', '-Wreal-q-constant' and '-Wunused'. - -'-Waliasing' - Warn about possible aliasing of dummy arguments. Specifically, it - warns if the same actual argument is associated with a dummy - argument with 'INTENT(IN)' and a dummy argument with 'INTENT(OUT)' - in a call with an explicit interface. - - The following example will trigger the warning. - interface - subroutine bar(a,b) - integer, intent(in) :: a - integer, intent(out) :: b - end subroutine - end interface - integer :: a - - call bar(a,a) - -'-Wampersand' - Warn about missing ampersand in continued character constants. The - warning is given with '-Wampersand', '-pedantic', '-std=f95', - '-std=f2003' and '-std=f2008'. Note: With no ampersand given in a - continued character constant, GNU Fortran assumes continuation at - the first non-comment, non-whitespace character after the ampersand - that initiated the continuation. - -'-Warray-temporaries' - Warn about array temporaries generated by the compiler. The - information generated by this warning is sometimes useful in - optimization, in order to avoid such temporaries. - -'-Wc-binding-type' - Warn if the a variable might not be C interoperable. In - particular, warn if the variable has been declared using an - intrinsic type with default kind instead of using a kind parameter - defined for C interoperability in the intrinsic 'ISO_C_Binding' - module. This option is implied by '-Wall'. - -'-Wcharacter-truncation' - Warn when a character assignment will truncate the assigned string. - -'-Wline-truncation' - Warn when a source code line will be truncated. This option is - implied by '-Wall'. - -'-Wconversion' - Warn about implicit conversions that are likely to change the value - of the expression after conversion. Implied by '-Wall'. - -'-Wconversion-extra' - Warn about implicit conversions between different types and kinds. - -'-Wextra' - Enables some warning options for usages of language features which - may be problematic. This currently includes '-Wcompare-reals' and - '-Wunused-parameter'. - -'-Wimplicit-interface' - Warn if a procedure is called without an explicit interface. Note - this only checks that an explicit interface is present. It does - not check that the declared interfaces are consistent across - program units. - -'-Wimplicit-procedure' - Warn if a procedure is called that has neither an explicit - interface nor has been declared as 'EXTERNAL'. - -'-Wintrinsics-std' - Warn if 'gfortran' finds a procedure named like an intrinsic not - available in the currently selected standard (with '-std') and - treats it as 'EXTERNAL' procedure because of this. - '-fall-intrinsics' can be used to never trigger this behavior and - always link to the intrinsic regardless of the selected standard. - -'-Wreal-q-constant' - Produce a warning if a real-literal-constant contains a 'q' - exponent-letter. - -'-Wsurprising' - Produce a warning when "suspicious" code constructs are - encountered. While technically legal these usually indicate that - an error has been made. - - This currently produces a warning under the following - circumstances: - - * An INTEGER SELECT construct has a CASE that can never be - matched as its lower value is greater than its upper value. - - * A LOGICAL SELECT construct has three CASE statements. - - * A TRANSFER specifies a source that is shorter than the - destination. - - * The type of a function result is declared more than once with - the same type. If '-pedantic' or standard-conforming mode is - enabled, this is an error. - - * A 'CHARACTER' variable is declared with negative length. - -'-Wtabs' - By default, tabs are accepted as whitespace, but tabs are not - members of the Fortran Character Set. For continuation lines, a - tab followed by a digit between 1 and 9 is supported. '-Wno-tabs' - will cause a warning to be issued if a tab is encountered. Note, - '-Wno-tabs' is active for '-pedantic', '-std=f95', '-std=f2003', - '-std=f2008' and '-Wall'. - -'-Wunderflow' - Produce a warning when numerical constant expressions are - encountered, which yield an UNDERFLOW during compilation. - -'-Wintrinsic-shadow' - Warn if a user-defined procedure or module procedure has the same - name as an intrinsic; in this case, an explicit interface or - 'EXTERNAL' or 'INTRINSIC' declaration might be needed to get calls - later resolved to the desired intrinsic/procedure. This option is - implied by '-Wall'. - -'-Wunused-dummy-argument' - Warn about unused dummy arguments. This option is implied by - '-Wall'. - -'-Wunused-parameter' - Contrary to 'gcc''s meaning of '-Wunused-parameter', 'gfortran''s - implementation of this option does not warn about unused dummy - arguments (see '-Wunused-dummy-argument'), but about unused - 'PARAMETER' values. '-Wunused-parameter' is not included in - '-Wall' but is implied by '-Wall -Wextra'. - -'-Walign-commons' - By default, 'gfortran' warns about any occasion of variables being - padded for proper alignment inside a 'COMMON' block. This warning - can be turned off via '-Wno-align-commons'. See also - '-falign-commons'. - -'-Wfunction-elimination' - Warn if any calls to functions are eliminated by the optimizations - enabled by the '-ffrontend-optimize' option. - -'-Wrealloc-lhs' - Warn when the compiler might insert code to for allocation or - reallocation of an allocatable array variable of intrinsic type in - intrinsic assignments. In hot loops, the Fortran 2003 reallocation - feature may reduce the performance. If the array is already - allocated with the correct shape, consider using a whole-array - array-spec (e.g. '(:,:,:)') for the variable on the left-hand side - to prevent the reallocation check. Note that in some cases the - warning is shown, even if the compiler will optimize reallocation - checks away. For instance, when the right-hand side contains the - same variable multiplied by a scalar. See also '-frealloc-lhs'. - -'-Wrealloc-lhs-all' - Warn when the compiler inserts code to for allocation or - reallocation of an allocatable variable; this includes scalars and - derived types. - -'-Wcompare-reals' - Warn when comparing real or complex types for equality or - inequality. This option is implied by '-Wextra'. - -'-Wtarget-lifetime' - Warn if the pointer in a pointer assignment might be longer than - the its target. This option is implied by '-Wall'. - -'-Wzerotrip' - Warn if a 'DO' loop is known to execute zero times at compile time. - This option is implied by '-Wall'. - -'-Werror' - Turns all warnings into errors. - - *Note Options to Request or Suppress Errors and Warnings: -(gcc)Warning Options, for information on more options offered by the GBE -shared by 'gfortran', 'gcc' and other GNU compilers. - - Some of these have no effect when compiling programs written in -Fortran. - - -File: gfortran.info, Node: Debugging Options, Next: Directory Options, Prev: Error and Warning Options, Up: Invoking GNU Fortran - -2.5 Options for debugging your program or GNU Fortran -===================================================== - -GNU Fortran has various special options that are used for debugging -either your program or the GNU Fortran compiler. - -'-fdump-fortran-original' - Output the internal parse tree after translating the source program - into internal representation. Only really useful for debugging the - GNU Fortran compiler itself. - -'-fdump-fortran-optimized' - Output the parse tree after front-end optimization. Only really - useful for debugging the GNU Fortran compiler itself. - -'-fdump-parse-tree' - Output the internal parse tree after translating the source program - into internal representation. Only really useful for debugging the - GNU Fortran compiler itself. This option is deprecated; use - '-fdump-fortran-original' instead. - -'-ffpe-trap=LIST' - Specify a list of floating point exception traps to enable. On - most systems, if a floating point exception occurs and the trap for - that exception is enabled, a SIGFPE signal will be sent and the - program being aborted, producing a core file useful for debugging. - LIST is a (possibly empty) comma-separated list of the following - exceptions: 'invalid' (invalid floating point operation, such as - 'SQRT(-1.0)'), 'zero' (division by zero), 'overflow' (overflow in a - floating point operation), 'underflow' (underflow in a floating - point operation), 'inexact' (loss of precision during operation), - and 'denormal' (operation performed on a denormal value). The - first five exceptions correspond to the five IEEE 754 exceptions, - whereas the last one ('denormal') is not part of the IEEE 754 - standard but is available on some common architectures such as x86. - - The first three exceptions ('invalid', 'zero', and 'overflow') - often indicate serious errors, and unless the program has - provisions for dealing with these exceptions, enabling traps for - these three exceptions is probably a good idea. - - Many, if not most, floating point operations incur loss of - precision due to rounding, and hence the 'ffpe-trap=inexact' is - likely to be uninteresting in practice. - - By default no exception traps are enabled. - -'-ffpe-summary=LIST' - Specify a list of floating-point exceptions, whose flag status is - printed to 'ERROR_UNIT' when invoking 'STOP' and 'ERROR STOP'. - LIST can be either 'none', 'all' or a comma-separated list of the - following exceptions: 'invalid', 'zero', 'overflow', 'underflow', - 'inexact' and 'denormal'. (See '-ffpe-trap' for a description of - the exceptions.) - - By default, a summary for all exceptions but 'inexact' is shown. - -'-fno-backtrace' - When a serious runtime error is encountered or a deadly signal is - emitted (segmentation fault, illegal instruction, bus error, - floating-point exception, and the other POSIX signals that have the - action 'core'), the Fortran runtime library tries to output a - backtrace of the error. '-fno-backtrace' disables the backtrace - generation. This option only has influence for compilation of the - Fortran main program. - - *Note Options for Debugging Your Program or GCC: (gcc)Debugging -Options, for more information on debugging options. - - -File: gfortran.info, Node: Directory Options, Next: Link Options, Prev: Debugging Options, Up: Invoking GNU Fortran - -2.6 Options for directory search -================================ - -These options affect how GNU Fortran searches for files specified by the -'INCLUDE' directive and where it searches for previously compiled -modules. - - It also affects the search paths used by 'cpp' when used to -preprocess Fortran source. - -'-IDIR' - These affect interpretation of the 'INCLUDE' directive (as well as - of the '#include' directive of the 'cpp' preprocessor). - - Also note that the general behavior of '-I' and 'INCLUDE' is pretty - much the same as of '-I' with '#include' in the 'cpp' preprocessor, - with regard to looking for 'header.gcc' files and other such - things. - - This path is also used to search for '.mod' files when previously - compiled modules are required by a 'USE' statement. - - *Note Options for Directory Search: (gcc)Directory Options, for - information on the '-I' option. - -'-JDIR' - This option specifies where to put '.mod' files for compiled - modules. It is also added to the list of directories to searched - by an 'USE' statement. - - The default is the current directory. - -'-fintrinsic-modules-path DIR' - This option specifies the location of pre-compiled intrinsic - modules, if they are not in the default location expected by the - compiler. - - -File: gfortran.info, Node: Link Options, Next: Runtime Options, Prev: Directory Options, Up: Invoking GNU Fortran - -2.7 Influencing the linking step -================================ - -These options come into play when the compiler links object files into -an executable output file. They are meaningless if the compiler is not -doing a link step. - -'-static-libgfortran' - On systems that provide 'libgfortran' as a shared and a static - library, this option forces the use of the static version. If no - shared version of 'libgfortran' was built when the compiler was - configured, this option has no effect. - - -File: gfortran.info, Node: Runtime Options, Next: Code Gen Options, Prev: Link Options, Up: Invoking GNU Fortran - -2.8 Influencing runtime behavior -================================ - -These options affect the runtime behavior of programs compiled with GNU -Fortran. - -'-fconvert=CONVERSION' - Specify the representation of data for unformatted files. Valid - values for conversion are: 'native', the default; 'swap', swap - between big- and little-endian; 'big-endian', use big-endian - representation for unformatted files; 'little-endian', use - little-endian representation for unformatted files. - - _This option has an effect only when used in the main program. The - 'CONVERT' specifier and the GFORTRAN_CONVERT_UNIT environment - variable override the default specified by '-fconvert'._ - -'-frecord-marker=LENGTH' - Specify the length of record markers for unformatted files. Valid - values for LENGTH are 4 and 8. Default is 4. _This is different - from previous versions of 'gfortran'_, which specified a default - record marker length of 8 on most systems. If you want to read or - write files compatible with earlier versions of 'gfortran', use - '-frecord-marker=8'. - -'-fmax-subrecord-length=LENGTH' - Specify the maximum length for a subrecord. The maximum permitted - value for length is 2147483639, which is also the default. Only - really useful for use by the gfortran testsuite. - -'-fsign-zero' - When enabled, floating point numbers of value zero with the sign - bit set are written as negative number in formatted output and - treated as negative in the 'SIGN' intrinsic. '-fno-sign-zero' does - not print the negative sign of zero values (or values rounded to - zero for I/O) and regards zero as positive number in the 'SIGN' - intrinsic for compatibility with Fortran 77. The default is - '-fsign-zero'. - - -File: gfortran.info, Node: Code Gen Options, Next: Environment Variables, Prev: Runtime Options, Up: Invoking GNU Fortran - -2.9 Options for code generation conventions -=========================================== - -These machine-independent options control the interface conventions used -in code generation. - - Most of them have both positive and negative forms; the negative form -of '-ffoo' would be '-fno-foo'. In the table below, only one of the -forms is listed--the one which is not the default. You can figure out -the other form by either removing 'no-' or adding it. - -'-fno-automatic' - Treat each program unit (except those marked as RECURSIVE) as if - the 'SAVE' statement were specified for every local variable and - array referenced in it. Does not affect common blocks. (Some - Fortran compilers provide this option under the name '-static' or - '-save'.) The default, which is '-fautomatic', uses the stack for - local variables smaller than the value given by - '-fmax-stack-var-size'. Use the option '-frecursive' to use no - static memory. - -'-ff2c' - Generate code designed to be compatible with code generated by - 'g77' and 'f2c'. - - The calling conventions used by 'g77' (originally implemented in - 'f2c') require functions that return type default 'REAL' to - actually return the C type 'double', and functions that return type - 'COMPLEX' to return the values via an extra argument in the calling - sequence that points to where to store the return value. Under the - default GNU calling conventions, such functions simply return their - results as they would in GNU C--default 'REAL' functions return the - C type 'float', and 'COMPLEX' functions return the GNU C type - 'complex'. Additionally, this option implies the - '-fsecond-underscore' option, unless '-fno-second-underscore' is - explicitly requested. - - This does not affect the generation of code that interfaces with - the 'libgfortran' library. - - _Caution:_ It is not a good idea to mix Fortran code compiled with - '-ff2c' with code compiled with the default '-fno-f2c' calling - conventions as, calling 'COMPLEX' or default 'REAL' functions - between program parts which were compiled with different calling - conventions will break at execution time. - - _Caution:_ This will break code which passes intrinsic functions of - type default 'REAL' or 'COMPLEX' as actual arguments, as the - library implementations use the '-fno-f2c' calling conventions. - -'-fno-underscoring' - Do not transform names of entities specified in the Fortran source - file by appending underscores to them. - - With '-funderscoring' in effect, GNU Fortran appends one underscore - to external names with no underscores. This is done to ensure - compatibility with code produced by many UNIX Fortran compilers. - - _Caution_: The default behavior of GNU Fortran is incompatible with - 'f2c' and 'g77', please use the '-ff2c' option if you want object - files compiled with GNU Fortran to be compatible with object code - created with these tools. - - Use of '-fno-underscoring' is not recommended unless you are - experimenting with issues such as integration of GNU Fortran into - existing system environments (vis-a`-vis existing libraries, tools, - and so on). - - For example, with '-funderscoring', and assuming other defaults - like '-fcase-lower' and that 'j()' and 'max_count()' are external - functions while 'my_var' and 'lvar' are local variables, a - statement like - I = J() + MAX_COUNT (MY_VAR, LVAR) - is implemented as something akin to: - i = j_() + max_count__(&my_var__, &lvar); - - With '-fno-underscoring', the same statement is implemented as: - - i = j() + max_count(&my_var, &lvar); - - Use of '-fno-underscoring' allows direct specification of - user-defined names while debugging and when interfacing GNU Fortran - code with other languages. - - Note that just because the names match does _not_ mean that the - interface implemented by GNU Fortran for an external name matches - the interface implemented by some other language for that same - name. That is, getting code produced by GNU Fortran to link to - code produced by some other compiler using this or any other method - can be only a small part of the overall solution--getting the code - generated by both compilers to agree on issues other than naming - can require significant effort, and, unlike naming disagreements, - linkers normally cannot detect disagreements in these other areas. - - Also, note that with '-fno-underscoring', the lack of appended - underscores introduces the very real possibility that a - user-defined external name will conflict with a name in a system - library, which could make finding unresolved-reference bugs quite - difficult in some cases--they might occur at program run time, and - show up only as buggy behavior at run time. - - In future versions of GNU Fortran we hope to improve naming and - linking issues so that debugging always involves using the names as - they appear in the source, even if the names as seen by the linker - are mangled to prevent accidental linking between procedures with - incompatible interfaces. - -'-fsecond-underscore' - By default, GNU Fortran appends an underscore to external names. - If this option is used GNU Fortran appends two underscores to names - with underscores and one underscore to external names with no - underscores. GNU Fortran also appends two underscores to internal - names with underscores to avoid naming collisions with external - names. - - This option has no effect if '-fno-underscoring' is in effect. It - is implied by the '-ff2c' option. - - Otherwise, with this option, an external name such as 'MAX_COUNT' - is implemented as a reference to the link-time external symbol - 'max_count__', instead of 'max_count_'. This is required for - compatibility with 'g77' and 'f2c', and is implied by use of the - '-ff2c' option. - -'-fcoarray=<KEYWORD>' - - 'none' - Disable coarray support; using coarray declarations and - image-control statements will produce a compile-time error. - (Default) - - 'single' - Single-image mode, i.e. 'num_images()' is always one. - - 'lib' - Library-based coarray parallelization; a suitable GNU Fortran - coarray library needs to be linked. - -'-fcheck=<KEYWORD>' - - Enable the generation of run-time checks; the argument shall be a - comma-delimited list of the following keywords. - - 'all' - Enable all run-time test of '-fcheck'. - - 'array-temps' - Warns at run time when for passing an actual argument a - temporary array had to be generated. The information - generated by this warning is sometimes useful in optimization, - in order to avoid such temporaries. - - Note: The warning is only printed once per location. - - 'bounds' - Enable generation of run-time checks for array subscripts and - against the declared minimum and maximum values. It also - checks array indices for assumed and deferred shape arrays - against the actual allocated bounds and ensures that all - string lengths are equal for character array constructors - without an explicit typespec. - - Some checks require that '-fcheck=bounds' is set for the - compilation of the main program. - - Note: In the future this may also include other forms of - checking, e.g., checking substring references. - - 'do' - Enable generation of run-time checks for invalid modification - of loop iteration variables. - - 'mem' - Enable generation of run-time checks for memory allocation. - Note: This option does not affect explicit allocations using - the 'ALLOCATE' statement, which will be always checked. - - 'pointer' - Enable generation of run-time checks for pointers and - allocatables. - - 'recursion' - Enable generation of run-time checks for recursively called - subroutines and functions which are not marked as recursive. - See also '-frecursive'. Note: This check does not work for - OpenMP programs and is disabled if used together with - '-frecursive' and '-fopenmp'. - -'-fbounds-check' - Deprecated alias for '-fcheck=bounds'. - -'-fcheck-array-temporaries' - Deprecated alias for '-fcheck=array-temps'. - -'-fmax-array-constructor=N' - This option can be used to increase the upper limit permitted in - array constructors. The code below requires this option to expand - the array at compile time. - - program test - implicit none - integer j - integer, parameter :: n = 100000 - integer, parameter :: i(n) = (/ (2*j, j = 1, n) /) - print '(10(I0,1X))', i - end program test - - _Caution: This option can lead to long compile times and - excessively large object files._ - - The default value for N is 65535. - -'-fmax-stack-var-size=N' - This option specifies the size in bytes of the largest array that - will be put on the stack; if the size is exceeded static memory is - used (except in procedures marked as RECURSIVE). Use the option - '-frecursive' to allow for recursive procedures which do not have a - RECURSIVE attribute or for parallel programs. Use '-fno-automatic' - to never use the stack. - - This option currently only affects local arrays declared with - constant bounds, and may not apply to all character variables. - Future versions of GNU Fortran may improve this behavior. - - The default value for N is 32768. - -'-fstack-arrays' - Adding this option will make the Fortran compiler put all local - arrays, even those of unknown size onto stack memory. If your - program uses very large local arrays it is possible that you will - have to extend your runtime limits for stack memory on some - operating systems. This flag is enabled by default at optimization - level '-Ofast'. - -'-fpack-derived' - This option tells GNU Fortran to pack derived type members as - closely as possible. Code compiled with this option is likely to - be incompatible with code compiled without this option, and may - execute slower. - -'-frepack-arrays' - In some circumstances GNU Fortran may pass assumed shape array - sections via a descriptor describing a noncontiguous area of - memory. This option adds code to the function prologue to repack - the data into a contiguous block at runtime. - - This should result in faster accesses to the array. However it can - introduce significant overhead to the function call, especially - when the passed data is noncontiguous. - -'-fshort-enums' - This option is provided for interoperability with C code that was - compiled with the '-fshort-enums' option. It will make GNU Fortran - choose the smallest 'INTEGER' kind a given enumerator set will fit - in, and give all its enumerators this kind. - -'-fexternal-blas' - This option will make 'gfortran' generate calls to BLAS functions - for some matrix operations like 'MATMUL', instead of using our own - algorithms, if the size of the matrices involved is larger than a - given limit (see '-fblas-matmul-limit'). This may be profitable if - an optimized vendor BLAS library is available. The BLAS library - will have to be specified at link time. - -'-fblas-matmul-limit=N' - Only significant when '-fexternal-blas' is in effect. Matrix - multiplication of matrices with size larger than (or equal to) N - will be performed by calls to BLAS functions, while others will be - handled by 'gfortran' internal algorithms. If the matrices - involved are not square, the size comparison is performed using the - geometric mean of the dimensions of the argument and result - matrices. - - The default value for N is 30. - -'-frecursive' - Allow indirect recursion by forcing all local arrays to be - allocated on the stack. This flag cannot be used together with - '-fmax-stack-var-size=' or '-fno-automatic'. - -'-finit-local-zero' -'-finit-integer=N' -'-finit-real=<ZERO|INF|-INF|NAN|SNAN>' -'-finit-logical=<TRUE|FALSE>' -'-finit-character=N' - The '-finit-local-zero' option instructs the compiler to initialize - local 'INTEGER', 'REAL', and 'COMPLEX' variables to zero, 'LOGICAL' - variables to false, and 'CHARACTER' variables to a string of null - bytes. Finer-grained initialization options are provided by the - '-finit-integer=N', '-finit-real=<ZERO|INF|-INF|NAN|SNAN>' (which - also initializes the real and imaginary parts of local 'COMPLEX' - variables), '-finit-logical=<TRUE|FALSE>', and '-finit-character=N' - (where N is an ASCII character value) options. These options do - not initialize - * allocatable arrays - * components of derived type variables - * variables that appear in an 'EQUIVALENCE' statement. - (These limitations may be removed in future releases). - - Note that the '-finit-real=nan' option initializes 'REAL' and - 'COMPLEX' variables with a quiet NaN. For a signalling NaN use - '-finit-real=snan'; note, however, that compile-time optimizations - may convert them into quiet NaN and that trapping needs to be - enabled (e.g. via '-ffpe-trap'). - - Finally, note that enabling any of the '-finit-*' options will - silence warnings that would have been emitted by '-Wuninitialized' - for the affected local variables. - -'-falign-commons' - By default, 'gfortran' enforces proper alignment of all variables - in a 'COMMON' block by padding them as needed. On certain - platforms this is mandatory, on others it increases performance. - If a 'COMMON' block is not declared with consistent data types - everywhere, this padding can cause trouble, and - '-fno-align-commons' can be used to disable automatic alignment. - The same form of this option should be used for all files that - share a 'COMMON' block. To avoid potential alignment issues in - 'COMMON' blocks, it is recommended to order objects from largest to - smallest. - -'-fno-protect-parens' - By default the parentheses in expression are honored for all - optimization levels such that the compiler does not do any - re-association. Using '-fno-protect-parens' allows the compiler to - reorder 'REAL' and 'COMPLEX' expressions to produce faster code. - Note that for the re-association optimization '-fno-signed-zeros' - and '-fno-trapping-math' need to be in effect. The parentheses - protection is enabled by default, unless '-Ofast' is given. - -'-frealloc-lhs' - An allocatable left-hand side of an intrinsic assignment is - automatically (re)allocated if it is either unallocated or has a - different shape. The option is enabled by default except when - '-std=f95' is given. See also '-Wrealloc-lhs'. - -'-faggressive-function-elimination' - Functions with identical argument lists are eliminated within - statements, regardless of whether these functions are marked 'PURE' - or not. For example, in - a = f(b,c) + f(b,c) - there will only be a single call to 'f'. This option only works if - '-ffrontend-optimize' is in effect. - -'-ffrontend-optimize' - This option performs front-end optimization, based on manipulating - parts the Fortran parse tree. Enabled by default by any '-O' - option. Optimizations enabled by this option include elimination - of identical function calls within expressions, removing - unnecessary calls to 'TRIM' in comparisons and assignments and - replacing 'TRIM(a)' with 'a(1:LEN_TRIM(a))'. It can be deselected - by specifying '-fno-frontend-optimize'. - - *Note Options for Code Generation Conventions: (gcc)Code Gen Options, -for information on more options offered by the GBE shared by 'gfortran', -'gcc', and other GNU compilers. - - -File: gfortran.info, Node: Environment Variables, Prev: Code Gen Options, Up: Invoking GNU Fortran - -2.10 Environment variables affecting 'gfortran' -=============================================== - -The 'gfortran' compiler currently does not make use of any environment -variables to control its operation above and beyond those that affect -the operation of 'gcc'. - - *Note Environment Variables Affecting GCC: (gcc)Environment -Variables, for information on environment variables. - - *Note Runtime::, for environment variables that affect the run-time -behavior of programs compiled with GNU Fortran. - - -File: gfortran.info, Node: Runtime, Next: Fortran 2003 and 2008 status, Prev: Invoking GNU Fortran, Up: Top - -3 Runtime: Influencing runtime behavior with environment variables -****************************************************************** - -The behavior of the 'gfortran' can be influenced by environment -variables. - - Malformed environment variables are silently ignored. - -* Menu: - -* TMPDIR:: Directory for scratch files -* GFORTRAN_STDIN_UNIT:: Unit number for standard input -* GFORTRAN_STDOUT_UNIT:: Unit number for standard output -* GFORTRAN_STDERR_UNIT:: Unit number for standard error -* GFORTRAN_UNBUFFERED_ALL:: Do not buffer I/O for all units. -* GFORTRAN_UNBUFFERED_PRECONNECTED:: Do not buffer I/O for preconnected units. -* GFORTRAN_SHOW_LOCUS:: Show location for runtime errors -* GFORTRAN_OPTIONAL_PLUS:: Print leading + where permitted -* GFORTRAN_DEFAULT_RECL:: Default record length for new files -* GFORTRAN_LIST_SEPARATOR:: Separator for list output -* GFORTRAN_CONVERT_UNIT:: Set endianness for unformatted I/O -* GFORTRAN_ERROR_BACKTRACE:: Show backtrace on run-time errors - - -File: gfortran.info, Node: TMPDIR, Next: GFORTRAN_STDIN_UNIT, Up: Runtime - -3.1 'TMPDIR'--Directory for scratch files -========================================= - -When opening a file with 'STATUS='SCRATCH'', GNU Fortran tries to create -the file in one of the potential directories by testing each directory -in the order below. - - 1. The environment variable 'TMPDIR', if it exists. - - 2. On the MinGW target, the directory returned by the 'GetTempPath' - function. Alternatively, on the Cygwin target, the 'TMP' and - 'TEMP' environment variables, if they exist, in that order. - - 3. The 'P_tmpdir' macro if it is defined, otherwise the directory - '/tmp'. - - -File: gfortran.info, Node: GFORTRAN_STDIN_UNIT, Next: GFORTRAN_STDOUT_UNIT, Prev: TMPDIR, Up: Runtime - -3.2 'GFORTRAN_STDIN_UNIT'--Unit number for standard input -========================================================= - -This environment variable can be used to select the unit number -preconnected to standard input. This must be a positive integer. The -default value is 5. - - -File: gfortran.info, Node: GFORTRAN_STDOUT_UNIT, Next: GFORTRAN_STDERR_UNIT, Prev: GFORTRAN_STDIN_UNIT, Up: Runtime - -3.3 'GFORTRAN_STDOUT_UNIT'--Unit number for standard output -=========================================================== - -This environment variable can be used to select the unit number -preconnected to standard output. This must be a positive integer. The -default value is 6. - - -File: gfortran.info, Node: GFORTRAN_STDERR_UNIT, Next: GFORTRAN_UNBUFFERED_ALL, Prev: GFORTRAN_STDOUT_UNIT, Up: Runtime - -3.4 'GFORTRAN_STDERR_UNIT'--Unit number for standard error -========================================================== - -This environment variable can be used to select the unit number -preconnected to standard error. This must be a positive integer. The -default value is 0. - - -File: gfortran.info, Node: GFORTRAN_UNBUFFERED_ALL, Next: GFORTRAN_UNBUFFERED_PRECONNECTED, Prev: GFORTRAN_STDERR_UNIT, Up: Runtime - -3.5 'GFORTRAN_UNBUFFERED_ALL'--Do not buffer I/O on all units -============================================================= - -This environment variable controls whether all I/O is unbuffered. If -the first letter is 'y', 'Y' or '1', all I/O is unbuffered. This will -slow down small sequential reads and writes. If the first letter is -'n', 'N' or '0', I/O is buffered. This is the default. - - -File: gfortran.info, Node: GFORTRAN_UNBUFFERED_PRECONNECTED, Next: GFORTRAN_SHOW_LOCUS, Prev: GFORTRAN_UNBUFFERED_ALL, Up: Runtime - -3.6 'GFORTRAN_UNBUFFERED_PRECONNECTED'--Do not buffer I/O on preconnected units -=============================================================================== - -The environment variable named 'GFORTRAN_UNBUFFERED_PRECONNECTED' -controls whether I/O on a preconnected unit (i.e. STDOUT or STDERR) is -unbuffered. If the first letter is 'y', 'Y' or '1', I/O is unbuffered. -This will slow down small sequential reads and writes. If the first -letter is 'n', 'N' or '0', I/O is buffered. This is the default. - - -File: gfortran.info, Node: GFORTRAN_SHOW_LOCUS, Next: GFORTRAN_OPTIONAL_PLUS, Prev: GFORTRAN_UNBUFFERED_PRECONNECTED, Up: Runtime - -3.7 'GFORTRAN_SHOW_LOCUS'--Show location for runtime errors -=========================================================== - -If the first letter is 'y', 'Y' or '1', filename and line numbers for -runtime errors are printed. If the first letter is 'n', 'N' or '0', do -not print filename and line numbers for runtime errors. The default is -to print the location. - - -File: gfortran.info, Node: GFORTRAN_OPTIONAL_PLUS, Next: GFORTRAN_DEFAULT_RECL, Prev: GFORTRAN_SHOW_LOCUS, Up: Runtime - -3.8 'GFORTRAN_OPTIONAL_PLUS'--Print leading + where permitted -============================================================= - -If the first letter is 'y', 'Y' or '1', a plus sign is printed where -permitted by the Fortran standard. If the first letter is 'n', 'N' or -'0', a plus sign is not printed in most cases. Default is not to print -plus signs. - - -File: gfortran.info, Node: GFORTRAN_DEFAULT_RECL, Next: GFORTRAN_LIST_SEPARATOR, Prev: GFORTRAN_OPTIONAL_PLUS, Up: Runtime - -3.9 'GFORTRAN_DEFAULT_RECL'--Default record length for new files -================================================================ - -This environment variable specifies the default record length, in bytes, -for files which are opened without a 'RECL' tag in the 'OPEN' statement. -This must be a positive integer. The default value is 1073741824 bytes -(1 GB). - - -File: gfortran.info, Node: GFORTRAN_LIST_SEPARATOR, Next: GFORTRAN_CONVERT_UNIT, Prev: GFORTRAN_DEFAULT_RECL, Up: Runtime - -3.10 'GFORTRAN_LIST_SEPARATOR'--Separator for list output -========================================================= - -This environment variable specifies the separator when writing -list-directed output. It may contain any number of spaces and at most -one comma. If you specify this on the command line, be sure to quote -spaces, as in - $ GFORTRAN_LIST_SEPARATOR=' , ' ./a.out - when 'a.out' is the compiled Fortran program that you want to run. -Default is a single space. - - -File: gfortran.info, Node: GFORTRAN_CONVERT_UNIT, Next: GFORTRAN_ERROR_BACKTRACE, Prev: GFORTRAN_LIST_SEPARATOR, Up: Runtime - -3.11 'GFORTRAN_CONVERT_UNIT'--Set endianness for unformatted I/O -================================================================ - -By setting the 'GFORTRAN_CONVERT_UNIT' variable, it is possible to -change the representation of data for unformatted files. The syntax for -the 'GFORTRAN_CONVERT_UNIT' variable is: - GFORTRAN_CONVERT_UNIT: mode | mode ';' exception | exception ; - mode: 'native' | 'swap' | 'big_endian' | 'little_endian' ; - exception: mode ':' unit_list | unit_list ; - unit_list: unit_spec | unit_list unit_spec ; - unit_spec: INTEGER | INTEGER '-' INTEGER ; - The variable consists of an optional default mode, followed by a list -of optional exceptions, which are separated by semicolons from the -preceding default and each other. Each exception consists of a format -and a comma-separated list of units. Valid values for the modes are the -same as for the 'CONVERT' specifier: - - 'NATIVE' Use the native format. This is the default. - 'SWAP' Swap between little- and big-endian. - 'LITTLE_ENDIAN' Use the little-endian format for unformatted files. - 'BIG_ENDIAN' Use the big-endian format for unformatted files. - A missing mode for an exception is taken to mean 'BIG_ENDIAN'. -Examples of values for 'GFORTRAN_CONVERT_UNIT' are: - ''big_endian'' Do all unformatted I/O in big_endian mode. - ''little_endian;native:10-20,25'' Do all unformatted I/O in - little_endian mode, except for units 10 to 20 and 25, which are in - native format. - ''10-20'' Units 10 to 20 are big-endian, the rest is native. - - Setting the environment variables should be done on the command line -or via the 'export' command for 'sh'-compatible shells and via 'setenv' -for 'csh'-compatible shells. - - Example for 'sh': - $ gfortran foo.f90 - $ GFORTRAN_CONVERT_UNIT='big_endian;native:10-20' ./a.out - - Example code for 'csh': - % gfortran foo.f90 - % setenv GFORTRAN_CONVERT_UNIT 'big_endian;native:10-20' - % ./a.out - - Using anything but the native representation for unformatted data -carries a significant speed overhead. If speed in this area matters to -you, it is best if you use this only for data that needs to be portable. - - *Note CONVERT specifier::, for an alternative way to specify the data -representation for unformatted files. *Note Runtime Options::, for -setting a default data representation for the whole program. The -'CONVERT' specifier overrides the '-fconvert' compile options. - - _Note that the values specified via the GFORTRAN_CONVERT_UNIT -environment variable will override the CONVERT specifier in the open -statement_. This is to give control over data formats to users who do -not have the source code of their program available. - - -File: gfortran.info, Node: GFORTRAN_ERROR_BACKTRACE, Prev: GFORTRAN_CONVERT_UNIT, Up: Runtime - -3.12 'GFORTRAN_ERROR_BACKTRACE'--Show backtrace on run-time errors -================================================================== - -If the 'GFORTRAN_ERROR_BACKTRACE' variable is set to 'y', 'Y' or '1' -(only the first letter is relevant) then a backtrace is printed when a -serious run-time error occurs. To disable the backtracing, set the -variable to 'n', 'N', '0'. Default is to print a backtrace unless the -'-fno-backtrace' compile option was used. - - -File: gfortran.info, Node: Fortran 2003 and 2008 status, Next: Compiler Characteristics, Prev: Runtime, Up: Top - -4 Fortran 2003 and 2008 Status -****************************** - -* Menu: - -* Fortran 2003 status:: -* Fortran 2008 status:: -* TS 29113 status:: - - -File: gfortran.info, Node: Fortran 2003 status, Next: Fortran 2008 status, Up: Fortran 2003 and 2008 status - -4.1 Fortran 2003 status -======================= - -GNU Fortran supports several Fortran 2003 features; an incomplete list -can be found below. See also the wiki page -(http://gcc.gnu.org/wiki/Fortran2003) about Fortran 2003. - - * Procedure pointers including procedure-pointer components with - 'PASS' attribute. - - * Procedures which are bound to a derived type (type-bound - procedures) including 'PASS', 'PROCEDURE' and 'GENERIC', and - operators bound to a type. - - * Abstract interfaces and type extension with the possibility to - override type-bound procedures or to have deferred binding. - - * Polymorphic entities ("'CLASS'") for derived types and unlimited - polymorphism ("'CLASS(*)'") - including 'SAME_TYPE_AS', - 'EXTENDS_TYPE_OF' and 'SELECT TYPE' for scalars and arrays and - finalization. - - * Generic interface names, which have the same name as derived types, - are now supported. This allows one to write constructor functions. - Note that Fortran does not support static constructor functions. - For static variables, only default initialization or - structure-constructor initialization are available. - - * The 'ASSOCIATE' construct. - - * Interoperability with C including enumerations, - - * In structure constructors the components with default values may be - omitted. - - * Extensions to the 'ALLOCATE' statement, allowing for a - type-specification with type parameter and for allocation and - initialization from a 'SOURCE=' expression; 'ALLOCATE' and - 'DEALLOCATE' optionally return an error message string via - 'ERRMSG='. - - * Reallocation on assignment: If an intrinsic assignment is used, an - allocatable variable on the left-hand side is automatically - allocated (if unallocated) or reallocated (if the shape is - different). Currently, scalar deferred character length left-hand - sides are correctly handled but arrays are not yet fully - implemented. - - * Deferred-length character variables and scalar deferred-length - character components of derived types are supported. (Note that - array-valued compoents are not yet implemented.) - - * Transferring of allocations via 'MOVE_ALLOC'. - - * The 'PRIVATE' and 'PUBLIC' attributes may be given individually to - derived-type components. - - * In pointer assignments, the lower bound may be specified and the - remapping of elements is supported. - - * For pointers an 'INTENT' may be specified which affect the - association status not the value of the pointer target. - - * Intrinsics 'command_argument_count', 'get_command', - 'get_command_argument', and 'get_environment_variable'. - - * Support for Unicode characters (ISO 10646) and UTF-8, including the - 'SELECTED_CHAR_KIND' and 'NEW_LINE' intrinsic functions. - - * Support for binary, octal and hexadecimal (BOZ) constants in the - intrinsic functions 'INT', 'REAL', 'CMPLX' and 'DBLE'. - - * Support for namelist variables with allocatable and pointer - attribute and nonconstant length type parameter. - - * Array constructors using square brackets. That is, '[...]' rather - than '(/.../)'. Type-specification for array constructors like '(/ - some-type :: ... /)'. - - * Extensions to the specification and initialization expressions, - including the support for intrinsics with real and complex - arguments. - - * Support for the asynchronous input/output syntax; however, the data - transfer is currently always synchronously performed. - - * 'FLUSH' statement. - - * 'IOMSG=' specifier for I/O statements. - - * Support for the declaration of enumeration constants via the 'ENUM' - and 'ENUMERATOR' statements. Interoperability with 'gcc' is - guaranteed also for the case where the '-fshort-enums' command line - option is given. - - * TR 15581: - * 'ALLOCATABLE' dummy arguments. - * 'ALLOCATABLE' function results - * 'ALLOCATABLE' components of derived types - - * The 'OPEN' statement supports the 'ACCESS='STREAM'' specifier, - allowing I/O without any record structure. - - * Namelist input/output for internal files. - - * Minor I/O features: Rounding during formatted output, using of a - decimal comma instead of a decimal point, setting whether a plus - sign should appear for positive numbers. On system where 'strtod' - honours the rounding mode, the rounding mode is also supported for - input. - - * The 'PROTECTED' statement and attribute. - - * The 'VALUE' statement and attribute. - - * The 'VOLATILE' statement and attribute. - - * The 'IMPORT' statement, allowing to import host-associated derived - types. - - * The intrinsic modules 'ISO_FORTRAN_ENVIRONMENT' is supported, which - contains parameters of the I/O units, storage sizes. Additionally, - procedures for C interoperability are available in the - 'ISO_C_BINDING' module. - - * 'USE' statement with 'INTRINSIC' and 'NON_INTRINSIC' attribute; - supported intrinsic modules: 'ISO_FORTRAN_ENV', 'ISO_C_BINDING', - 'OMP_LIB' and 'OMP_LIB_KINDS'. - - * Renaming of operators in the 'USE' statement. - - -File: gfortran.info, Node: Fortran 2008 status, Next: TS 29113 status, Prev: Fortran 2003 status, Up: Fortran 2003 and 2008 status - -4.2 Fortran 2008 status -======================= - -The latest version of the Fortran standard is ISO/IEC 1539-1:2010, -informally known as Fortran 2008. The official version is available -from International Organization for Standardization (ISO) or its -national member organizations. The the final draft (FDIS) can be -downloaded free of charge from -<http://www.nag.co.uk/sc22wg5/links.html>. Fortran is developed by the -Working Group 5 of Sub-Committee 22 of the Joint Technical Committee 1 -of the International Organization for Standardization and the -International Electrotechnical Commission (IEC). This group is known as -WG5 (http://www.nag.co.uk/sc22wg5/). - - The GNU Fortran compiler supports several of the new features of -Fortran 2008; the wiki (http://gcc.gnu.org/wiki/Fortran2008Status) has -some information about the current Fortran 2008 implementation status. -In particular, the following is implemented. - - * The '-std=f2008' option and support for the file extensions '.f08' - and '.F08'. - - * The 'OPEN' statement now supports the 'NEWUNIT=' option, which - returns a unique file unit, thus preventing inadvertent use of the - same unit in different parts of the program. - - * The 'g0' format descriptor and unlimited format items. - - * The mathematical intrinsics 'ASINH', 'ACOSH', 'ATANH', 'ERF', - 'ERFC', 'GAMMA', 'LOG_GAMMA', 'BESSEL_J0', 'BESSEL_J1', - 'BESSEL_JN', 'BESSEL_Y0', 'BESSEL_Y1', 'BESSEL_YN', 'HYPOT', - 'NORM2', and 'ERFC_SCALED'. - - * Using complex arguments with 'TAN', 'SINH', 'COSH', 'TANH', 'ASIN', - 'ACOS', and 'ATAN' is now possible; 'ATAN'(Y,X) is now an alias for - 'ATAN2'(Y,X). - - * Support of the 'PARITY' intrinsic functions. - - * The following bit intrinsics: 'LEADZ' and 'TRAILZ' for counting the - number of leading and trailing zero bits, 'POPCNT' and 'POPPAR' for - counting the number of one bits and returning the parity; 'BGE', - 'BGT', 'BLE', and 'BLT' for bitwise comparisons; 'DSHIFTL' and - 'DSHIFTR' for combined left and right shifts, 'MASKL' and 'MASKR' - for simple left and right justified masks, 'MERGE_BITS' for a - bitwise merge using a mask, 'SHIFTA', 'SHIFTL' and 'SHIFTR' for - shift operations, and the transformational bit intrinsics 'IALL', - 'IANY' and 'IPARITY'. - - * Support of the 'EXECUTE_COMMAND_LINE' intrinsic subroutine. - - * Support for the 'STORAGE_SIZE' intrinsic inquiry function. - - * The 'INT{8,16,32}' and 'REAL{32,64,128}' kind type parameters and - the array-valued named constants 'INTEGER_KINDS', 'LOGICAL_KINDS', - 'REAL_KINDS' and 'CHARACTER_KINDS' of the intrinsic module - 'ISO_FORTRAN_ENV'. - - * The module procedures 'C_SIZEOF' of the intrinsic module - 'ISO_C_BINDINGS' and 'COMPILER_VERSION' and 'COMPILER_OPTIONS' of - 'ISO_FORTRAN_ENV'. - - * Coarray support for serial programs with '-fcoarray=single' flag - and experimental support for multiple images with the - '-fcoarray=lib' flag. - - * The 'DO CONCURRENT' construct is supported. - - * The 'BLOCK' construct is supported. - - * The 'STOP' and the new 'ERROR STOP' statements now support all - constant expressions. Both show the signals which were signaling - at termination. - - * Support for the 'CONTIGUOUS' attribute. - - * Support for 'ALLOCATE' with 'MOLD'. - - * Support for the 'IMPURE' attribute for procedures, which allows for - 'ELEMENTAL' procedures without the restrictions of 'PURE'. - - * Null pointers (including 'NULL()') and not-allocated variables can - be used as actual argument to optional non-pointer, non-allocatable - dummy arguments, denoting an absent argument. - - * Non-pointer variables with 'TARGET' attribute can be used as actual - argument to 'POINTER' dummies with 'INTENT(IN)'. - - * Pointers including procedure pointers and those in a derived type - (pointer components) can now be initialized by a target instead of - only by 'NULL'. - - * The 'EXIT' statement (with construct-name) can be now be used to - leave not only the 'DO' but also the 'ASSOCIATE', 'BLOCK', 'IF', - 'SELECT CASE' and 'SELECT TYPE' constructs. - - * Internal procedures can now be used as actual argument. - - * Minor features: obsolesce diagnostics for 'ENTRY' with - '-std=f2008'; a line may start with a semicolon; for internal and - module procedures 'END' can be used instead of 'END SUBROUTINE' and - 'END FUNCTION'; 'SELECTED_REAL_KIND' now also takes a 'RADIX' - argument; intrinsic types are supported for - 'TYPE'(INTRINSIC-TYPE-SPEC); multiple type-bound procedures can be - declared in a single 'PROCEDURE' statement; implied-shape arrays - are supported for named constants ('PARAMETER'). - - -File: gfortran.info, Node: TS 29113 status, Prev: Fortran 2008 status, Up: Fortran 2003 and 2008 status - -4.3 Technical Specification 29113 Status -======================================== - -GNU Fortran supports some of the new features of the Technical -Specification (TS) 29113 on Further Interoperability of Fortran with C. -The wiki (http://gcc.gnu.org/wiki/TS29113Status) has some information -about the current TS 29113 implementation status. In particular, the -following is implemented. - - See also *note Further Interoperability of Fortran with C::. - - * The '-std=f2008ts' option. - - * The 'OPTIONAL' attribute is allowed for dummy arguments of 'BIND(C) - procedures.' - - * The 'RANK' intrinsic is supported. - - * GNU Fortran's implementation for variables with 'ASYNCHRONOUS' - attribute is compatible with TS 29113. - - * Assumed types ('TYPE(*)'. - - * Assumed-rank ('DIMENSION(..)'). However, the array descriptor of - the TS is not yet supported. - - -File: gfortran.info, Node: Compiler Characteristics, Next: Extensions, Prev: Fortran 2003 and 2008 status, Up: Top - -5 Compiler Characteristics -************************** - -This chapter describes certain characteristics of the GNU Fortran -compiler, that are not specified by the Fortran standard, but which -might in some way or another become visible to the programmer. - -* Menu: - -* KIND Type Parameters:: -* Internal representation of LOGICAL variables:: -* Thread-safety of the runtime library:: -* Data consistency and durability:: - - -File: gfortran.info, Node: KIND Type Parameters, Next: Internal representation of LOGICAL variables, Up: Compiler Characteristics - -5.1 KIND Type Parameters -======================== - -The 'KIND' type parameters supported by GNU Fortran for the primitive -data types are: - -'INTEGER' - 1, 2, 4, 8*, 16*, default: 4** - -'LOGICAL' - 1, 2, 4, 8*, 16*, default: 4** - -'REAL' - 4, 8, 10*, 16*, default: 4*** - -'COMPLEX' - 4, 8, 10*, 16*, default: 4*** - -'DOUBLE PRECISION' - 4, 8, 10*, 16*, default: 8*** - -'CHARACTER' - 1, 4, default: 1 - -* not available on all systems -** unless '-fdefault-integer-8' is used -*** unless '-fdefault-real-8' is used (see *note Fortran Dialect -Options::) - -The 'KIND' value matches the storage size in bytes, except for 'COMPLEX' -where the storage size is twice as much (or both real and imaginary part -are a real value of the given size). It is recommended to use the *note -SELECTED_CHAR_KIND::, *note SELECTED_INT_KIND:: and *note -SELECTED_REAL_KIND:: intrinsics or the 'INT8', 'INT16', 'INT32', -'INT64', 'REAL32', 'REAL64', and 'REAL128' parameters of the -'ISO_FORTRAN_ENV' module instead of the concrete values. The available -kind parameters can be found in the constant arrays 'CHARACTER_KINDS', -'INTEGER_KINDS', 'LOGICAL_KINDS' and 'REAL_KINDS' in the *note -ISO_FORTRAN_ENV:: module. For C interoperability, the kind parameters -of the *note ISO_C_BINDING:: module should be used. - - -File: gfortran.info, Node: Internal representation of LOGICAL variables, Next: Thread-safety of the runtime library, Prev: KIND Type Parameters, Up: Compiler Characteristics - -5.2 Internal representation of LOGICAL variables -================================================ - -The Fortran standard does not specify how variables of 'LOGICAL' type -are represented, beyond requiring that 'LOGICAL' variables of default -kind have the same storage size as default 'INTEGER' and 'REAL' -variables. The GNU Fortran internal representation is as follows. - - A 'LOGICAL(KIND=N)' variable is represented as an 'INTEGER(KIND=N)' -variable, however, with only two permissible values: '1' for '.TRUE.' -and '0' for '.FALSE.'. Any other integer value results in undefined -behavior. - - See also *note Argument passing conventions:: and *note -Interoperability with C::. - - -File: gfortran.info, Node: Thread-safety of the runtime library, Next: Data consistency and durability, Prev: Internal representation of LOGICAL variables, Up: Compiler Characteristics - -5.3 Thread-safety of the runtime library -======================================== - -GNU Fortran can be used in programs with multiple threads, e.g. by using -OpenMP, by calling OS thread handling functions via the 'ISO_C_BINDING' -facility, or by GNU Fortran compiled library code being called from a -multi-threaded program. - - The GNU Fortran runtime library, ('libgfortran'), supports being -called concurrently from multiple threads with the following exceptions. - - During library initialization, the C 'getenv' function is used, which -need not be thread-safe. Similarly, the 'getenv' function is used to -implement the 'GET_ENVIRONMENT_VARIABLE' and 'GETENV' intrinsics. It is -the responsibility of the user to ensure that the environment is not -being updated concurrently when any of these actions are taking place. - - The 'EXECUTE_COMMAND_LINE' and 'SYSTEM' intrinsics are implemented -with the 'system' function, which need not be thread-safe. It is the -responsibility of the user to ensure that 'system' is not called -concurrently. - - Finally, for platforms not supporting thread-safe POSIX functions, -further functionality might not be thread-safe. For details, please -consult the documentation for your operating system. - - -File: gfortran.info, Node: Data consistency and durability, Prev: Thread-safety of the runtime library, Up: Compiler Characteristics - -5.4 Data consistency and durability -=================================== - -This section contains a brief overview of data and metadata consistency -and durability issues when doing I/O. - - With respect to durability, GNU Fortran makes no effort to ensure -that data is committed to stable storage. If this is required, the GNU -Fortran programmer can use the intrinsic 'FNUM' to retrieve the low -level file descriptor corresponding to an open Fortran unit. Then, -using e.g. the 'ISO_C_BINDING' feature, one can call the underlying -system call to flush dirty data to stable storage, such as 'fsync' on -POSIX, '_commit' on MingW, or 'fcntl(fd, F_FULLSYNC, 0)' on Mac OS X. -The following example shows how to call fsync: - - ! Declare the interface for POSIX fsync function - interface - function fsync (fd) bind(c,name="fsync") - use iso_c_binding, only: c_int - integer(c_int), value :: fd - integer(c_int) :: fsync - end function fsync - end interface - - ! Variable declaration - integer :: ret - - ! Opening unit 10 - open (10,file="foo") - - ! ... - ! Perform I/O on unit 10 - ! ... - - ! Flush and sync - flush(10) - ret = fsync(fnum(10)) - - ! Handle possible error - if (ret /= 0) stop "Error calling FSYNC" - - With respect to consistency, for regular files GNU Fortran uses -buffered I/O in order to improve performance. This buffer is flushed -automatically when full and in some other situations, e.g. when closing -a unit. It can also be explicitly flushed with the 'FLUSH' statement. -Also, the buffering can be turned off with the 'GFORTRAN_UNBUFFERED_ALL' -and 'GFORTRAN_UNBUFFERED_PRECONNECTED' environment variables. Special -files, such as terminals and pipes, are always unbuffered. Sometimes, -however, further things may need to be done in order to allow other -processes to see data that GNU Fortran has written, as follows. - - The Windows platform supports a relaxed metadata consistency model, -where file metadata is written to the directory lazily. This means -that, for instance, the 'dir' command can show a stale size for a file. -One can force a directory metadata update by closing the unit, or by -calling '_commit' on the file descriptor. Note, though, that '_commit' -will force all dirty data to stable storage, which is often a very slow -operation. - - The Network File System (NFS) implements a relaxed consistency model -called open-to-close consistency. Closing a file forces dirty data and -metadata to be flushed to the server, and opening a file forces the -client to contact the server in order to revalidate cached data. -'fsync' will also force a flush of dirty data and metadata to the -server. Similar to 'open' and 'close', acquiring and releasing 'fcntl' -file locks, if the server supports them, will also force cache -validation and flushing dirty data and metadata. - - -File: gfortran.info, Node: Extensions, Next: Mixed-Language Programming, Prev: Compiler Characteristics, Up: Top - -6 Extensions -************ - -The two sections below detail the extensions to standard Fortran that -are implemented in GNU Fortran, as well as some of the popular or -historically important extensions that are not (or not yet) implemented. -For the latter case, we explain the alternatives available to GNU -Fortran users, including replacement by standard-conforming code or GNU -extensions. - -* Menu: - -* Extensions implemented in GNU Fortran:: -* Extensions not implemented in GNU Fortran:: - - -File: gfortran.info, Node: Extensions implemented in GNU Fortran, Next: Extensions not implemented in GNU Fortran, Up: Extensions - -6.1 Extensions implemented in GNU Fortran -========================================= - -GNU Fortran implements a number of extensions over standard Fortran. -This chapter contains information on their syntax and meaning. There -are currently two categories of GNU Fortran extensions, those that -provide functionality beyond that provided by any standard, and those -that are supported by GNU Fortran purely for backward compatibility with -legacy compilers. By default, '-std=gnu' allows the compiler to accept -both types of extensions, but to warn about the use of the latter. -Specifying either '-std=f95', '-std=f2003' or '-std=f2008' disables both -types of extensions, and '-std=legacy' allows both without warning. - -* Menu: - -* Old-style kind specifications:: -* Old-style variable initialization:: -* Extensions to namelist:: -* X format descriptor without count field:: -* Commas in FORMAT specifications:: -* Missing period in FORMAT specifications:: -* I/O item lists:: -* 'Q' exponent-letter:: -* BOZ literal constants:: -* Real array indices:: -* Unary operators:: -* Implicitly convert LOGICAL and INTEGER values:: -* Hollerith constants support:: -* Cray pointers:: -* CONVERT specifier:: -* OpenMP:: -* Argument list functions:: - - -File: gfortran.info, Node: Old-style kind specifications, Next: Old-style variable initialization, Up: Extensions implemented in GNU Fortran - -6.1.1 Old-style kind specifications ------------------------------------ - -GNU Fortran allows old-style kind specifications in declarations. These -look like: - TYPESPEC*size x,y,z -where 'TYPESPEC' is a basic type ('INTEGER', 'REAL', etc.), and where -'size' is a byte count corresponding to the storage size of a valid kind -for that type. (For 'COMPLEX' variables, 'size' is the total size of -the real and imaginary parts.) The statement then declares 'x', 'y' and -'z' to be of type 'TYPESPEC' with the appropriate kind. This is -equivalent to the standard-conforming declaration - TYPESPEC(k) x,y,z -where 'k' is the kind parameter suitable for the intended precision. As -kind parameters are implementation-dependent, use the 'KIND', -'SELECTED_INT_KIND' and 'SELECTED_REAL_KIND' intrinsics to retrieve the -correct value, for instance 'REAL*8 x' can be replaced by: - INTEGER, PARAMETER :: dbl = KIND(1.0d0) - REAL(KIND=dbl) :: x - - -File: gfortran.info, Node: Old-style variable initialization, Next: Extensions to namelist, Prev: Old-style kind specifications, Up: Extensions implemented in GNU Fortran - -6.1.2 Old-style variable initialization ---------------------------------------- - -GNU Fortran allows old-style initialization of variables of the form: - INTEGER i/1/,j/2/ - REAL x(2,2) /3*0.,1./ - The syntax for the initializers is as for the 'DATA' statement, but -unlike in a 'DATA' statement, an initializer only applies to the -variable immediately preceding the initialization. In other words, -something like 'INTEGER I,J/2,3/' is not valid. This style of -initialization is only allowed in declarations without double colons -('::'); the double colons were introduced in Fortran 90, which also -introduced a standard syntax for initializing variables in type -declarations. - - Examples of standard-conforming code equivalent to the above example -are: - ! Fortran 90 - INTEGER :: i = 1, j = 2 - REAL :: x(2,2) = RESHAPE((/0.,0.,0.,1./),SHAPE(x)) - ! Fortran 77 - INTEGER i, j - REAL x(2,2) - DATA i/1/, j/2/, x/3*0.,1./ - - Note that variables which are explicitly initialized in declarations -or in 'DATA' statements automatically acquire the 'SAVE' attribute. - - -File: gfortran.info, Node: Extensions to namelist, Next: X format descriptor without count field, Prev: Old-style variable initialization, Up: Extensions implemented in GNU Fortran - -6.1.3 Extensions to namelist ----------------------------- - -GNU Fortran fully supports the Fortran 95 standard for namelist I/O -including array qualifiers, substrings and fully qualified derived -types. The output from a namelist write is compatible with namelist -read. The output has all names in upper case and indentation to column -1 after the namelist name. Two extensions are permitted: - - Old-style use of '$' instead of '&' - $MYNML - X(:)%Y(2) = 1.0 2.0 3.0 - CH(1:4) = "abcd" - $END - - It should be noted that the default terminator is '/' rather than -'&END'. - - Querying of the namelist when inputting from stdin. After at least -one space, entering '?' sends to stdout the namelist name and the names -of the variables in the namelist: - ? - - &mynml - x - x%y - ch - &end - - Entering '=?' outputs the namelist to stdout, as if 'WRITE(*,NML = -mynml)' had been called: - =? - - &MYNML - X(1)%Y= 0.000000 , 1.000000 , 0.000000 , - X(2)%Y= 0.000000 , 2.000000 , 0.000000 , - X(3)%Y= 0.000000 , 3.000000 , 0.000000 , - CH=abcd, / - - To aid this dialog, when input is from stdin, errors send their -messages to stderr and execution continues, even if 'IOSTAT' is set. - - 'PRINT' namelist is permitted. This causes an error if '-std=f95' is -used. - PROGRAM test_print - REAL, dimension (4) :: x = (/1.0, 2.0, 3.0, 4.0/) - NAMELIST /mynml/ x - PRINT mynml - END PROGRAM test_print - - Expanded namelist reads are permitted. This causes an error if -'-std=f95' is used. In the following example, the first element of the -array will be given the value 0.00 and the two succeeding elements will -be given the values 1.00 and 2.00. - &MYNML - X(1,1) = 0.00 , 1.00 , 2.00 - / - - When writing a namelist, if no 'DELIM=' is specified, by default a -double quote is used to delimit character strings. If -std=F95, F2003, -or F2008, etc, the delim status is set to 'none'. Defaulting to quotes -ensures that namelists with character strings can be subsequently read -back in accurately. - - -File: gfortran.info, Node: X format descriptor without count field, Next: Commas in FORMAT specifications, Prev: Extensions to namelist, Up: Extensions implemented in GNU Fortran - -6.1.4 'X' format descriptor without count field ------------------------------------------------ - -To support legacy codes, GNU Fortran permits the count field of the 'X' -edit descriptor in 'FORMAT' statements to be omitted. When omitted, the -count is implicitly assumed to be one. - - PRINT 10, 2, 3 - 10 FORMAT (I1, X, I1) - - -File: gfortran.info, Node: Commas in FORMAT specifications, Next: Missing period in FORMAT specifications, Prev: X format descriptor without count field, Up: Extensions implemented in GNU Fortran - -6.1.5 Commas in 'FORMAT' specifications ---------------------------------------- - -To support legacy codes, GNU Fortran allows the comma separator to be -omitted immediately before and after character string edit descriptors -in 'FORMAT' statements. - - PRINT 10, 2, 3 - 10 FORMAT ('FOO='I1' BAR='I2) - - -File: gfortran.info, Node: Missing period in FORMAT specifications, Next: I/O item lists, Prev: Commas in FORMAT specifications, Up: Extensions implemented in GNU Fortran - -6.1.6 Missing period in 'FORMAT' specifications ------------------------------------------------ - -To support legacy codes, GNU Fortran allows missing periods in format -specifications if and only if '-std=legacy' is given on the command -line. This is considered non-conforming code and is discouraged. - - REAL :: value - READ(*,10) value - 10 FORMAT ('F4') - - -File: gfortran.info, Node: I/O item lists, Next: 'Q' exponent-letter, Prev: Missing period in FORMAT specifications, Up: Extensions implemented in GNU Fortran - -6.1.7 I/O item lists --------------------- - -To support legacy codes, GNU Fortran allows the input item list of the -'READ' statement, and the output item lists of the 'WRITE' and 'PRINT' -statements, to start with a comma. - - -File: gfortran.info, Node: 'Q' exponent-letter, Next: BOZ literal constants, Prev: I/O item lists, Up: Extensions implemented in GNU Fortran - -6.1.8 'Q' exponent-letter -------------------------- - -GNU Fortran accepts real literal constants with an exponent-letter of -'Q', for example, '1.23Q45'. The constant is interpreted as a -'REAL(16)' entity on targets that support this type. If the target does -not support 'REAL(16)' but has a 'REAL(10)' type, then the -real-literal-constant will be interpreted as a 'REAL(10)' entity. In -the absence of 'REAL(16)' and 'REAL(10)', an error will occur. - - -File: gfortran.info, Node: BOZ literal constants, Next: Real array indices, Prev: 'Q' exponent-letter, Up: Extensions implemented in GNU Fortran - -6.1.9 BOZ literal constants ---------------------------- - -Besides decimal constants, Fortran also supports binary ('b'), octal -('o') and hexadecimal ('z') integer constants. The syntax is: 'prefix -quote digits quote', were the prefix is either 'b', 'o' or 'z', quote is -either ''' or '"' and the digits are for binary '0' or '1', for octal -between '0' and '7', and for hexadecimal between '0' and 'F'. (Example: -'b'01011101''.) - - Up to Fortran 95, BOZ literals were only allowed to initialize -integer variables in DATA statements. Since Fortran 2003 BOZ literals -are also allowed as argument of 'REAL', 'DBLE', 'INT' and 'CMPLX'; the -result is the same as if the integer BOZ literal had been converted by -'TRANSFER' to, respectively, 'real', 'double precision', 'integer' or -'complex'. As GNU Fortran extension the intrinsic procedures 'FLOAT', -'DFLOAT', 'COMPLEX' and 'DCMPLX' are treated alike. - - As an extension, GNU Fortran allows hexadecimal BOZ literal constants -to be specified using the 'X' prefix, in addition to the standard 'Z' -prefix. The BOZ literal can also be specified by adding a suffix to the -string, for example, 'Z'ABC'' and ''ABC'Z' are equivalent. - - Furthermore, GNU Fortran allows using BOZ literal constants outside -DATA statements and the four intrinsic functions allowed by Fortran -2003. In DATA statements, in direct assignments, where the right-hand -side only contains a BOZ literal constant, and for old-style -initializers of the form 'integer i /o'0173'/', the constant is -transferred as if 'TRANSFER' had been used; for 'COMPLEX' numbers, only -the real part is initialized unless 'CMPLX' is used. In all other -cases, the BOZ literal constant is converted to an 'INTEGER' value with -the largest decimal representation. This value is then converted -numerically to the type and kind of the variable in question. (For -instance, 'real :: r = b'0000001' + 1' initializes 'r' with '2.0'.) As -different compilers implement the extension differently, one should be -careful when doing bitwise initialization of non-integer variables. - - Note that initializing an 'INTEGER' variable with a statement such as -'DATA i/Z'FFFFFFFF'/' will give an integer overflow error rather than -the desired result of -1 when 'i' is a 32-bit integer on a system that -supports 64-bit integers. The '-fno-range-check' option can be used as -a workaround for legacy code that initializes integers in this manner. - - -File: gfortran.info, Node: Real array indices, Next: Unary operators, Prev: BOZ literal constants, Up: Extensions implemented in GNU Fortran - -6.1.10 Real array indices -------------------------- - -As an extension, GNU Fortran allows the use of 'REAL' expressions or -variables as array indices. - - -File: gfortran.info, Node: Unary operators, Next: Implicitly convert LOGICAL and INTEGER values, Prev: Real array indices, Up: Extensions implemented in GNU Fortran - -6.1.11 Unary operators ----------------------- - -As an extension, GNU Fortran allows unary plus and unary minus operators -to appear as the second operand of binary arithmetic operators without -the need for parenthesis. - - X = Y * -Z - - -File: gfortran.info, Node: Implicitly convert LOGICAL and INTEGER values, Next: Hollerith constants support, Prev: Unary operators, Up: Extensions implemented in GNU Fortran - -6.1.12 Implicitly convert 'LOGICAL' and 'INTEGER' values --------------------------------------------------------- - -As an extension for backwards compatibility with other compilers, GNU -Fortran allows the implicit conversion of 'LOGICAL' values to 'INTEGER' -values and vice versa. When converting from a 'LOGICAL' to an -'INTEGER', '.FALSE.' is interpreted as zero, and '.TRUE.' is interpreted -as one. When converting from 'INTEGER' to 'LOGICAL', the value zero is -interpreted as '.FALSE.' and any nonzero value is interpreted as -'.TRUE.'. - - LOGICAL :: l - l = 1 - INTEGER :: i - i = .TRUE. - - However, there is no implicit conversion of 'INTEGER' values in -'if'-statements, nor of 'LOGICAL' or 'INTEGER' values in I/O operations. - - -File: gfortran.info, Node: Hollerith constants support, Next: Cray pointers, Prev: Implicitly convert LOGICAL and INTEGER values, Up: Extensions implemented in GNU Fortran - -6.1.13 Hollerith constants support ----------------------------------- - -GNU Fortran supports Hollerith constants in assignments, function -arguments, and 'DATA' and 'ASSIGN' statements. A Hollerith constant is -written as a string of characters preceded by an integer constant -indicating the character count, and the letter 'H' or 'h', and stored in -bytewise fashion in a numeric ('INTEGER', 'REAL', or 'complex') or -'LOGICAL' variable. The constant will be padded or truncated to fit the -size of the variable in which it is stored. - - Examples of valid uses of Hollerith constants: - complex*16 x(2) - data x /16Habcdefghijklmnop, 16Hqrstuvwxyz012345/ - x(1) = 16HABCDEFGHIJKLMNOP - call foo (4h abc) - - Invalid Hollerith constants examples: - integer*4 a - a = 8H12345678 ! Valid, but the Hollerith constant will be truncated. - a = 0H ! At least one character is needed. - - In general, Hollerith constants were used to provide a rudimentary -facility for handling character strings in early Fortran compilers, -prior to the introduction of 'CHARACTER' variables in Fortran 77; in -those cases, the standard-compliant equivalent is to convert the program -to use proper character strings. On occasion, there may be a case where -the intent is specifically to initialize a numeric variable with a given -byte sequence. In these cases, the same result can be obtained by using -the 'TRANSFER' statement, as in this example. - INTEGER(KIND=4) :: a - a = TRANSFER ("abcd", a) ! equivalent to: a = 4Habcd - - -File: gfortran.info, Node: Cray pointers, Next: CONVERT specifier, Prev: Hollerith constants support, Up: Extensions implemented in GNU Fortran - -6.1.14 Cray pointers --------------------- - -Cray pointers are part of a non-standard extension that provides a -C-like pointer in Fortran. This is accomplished through a pair of -variables: an integer "pointer" that holds a memory address, and a -"pointee" that is used to dereference the pointer. - - Pointer/pointee pairs are declared in statements of the form: - pointer ( <pointer> , <pointee> ) - or, - pointer ( <pointer1> , <pointee1> ), ( <pointer2> , <pointee2> ), ... - The pointer is an integer that is intended to hold a memory address. -The pointee may be an array or scalar. A pointee can be an assumed size -array--that is, the last dimension may be left unspecified by using a -'*' in place of a value--but a pointee cannot be an assumed shape array. -No space is allocated for the pointee. - - The pointee may have its type declared before or after the pointer -statement, and its array specification (if any) may be declared before, -during, or after the pointer statement. The pointer may be declared as -an integer prior to the pointer statement. However, some machines have -default integer sizes that are different than the size of a pointer, and -so the following code is not portable: - integer ipt - pointer (ipt, iarr) - If a pointer is declared with a kind that is too small, the compiler -will issue a warning; the resulting binary will probably not work -correctly, because the memory addresses stored in the pointers may be -truncated. It is safer to omit the first line of the above example; if -explicit declaration of ipt's type is omitted, then the compiler will -ensure that ipt is an integer variable large enough to hold a pointer. - - Pointer arithmetic is valid with Cray pointers, but it is not the -same as C pointer arithmetic. Cray pointers are just ordinary integers, -so the user is responsible for determining how many bytes to add to a -pointer in order to increment it. Consider the following example: - real target(10) - real pointee(10) - pointer (ipt, pointee) - ipt = loc (target) - ipt = ipt + 1 - The last statement does not set 'ipt' to the address of 'target(1)', -as it would in C pointer arithmetic. Adding '1' to 'ipt' just adds one -byte to the address stored in 'ipt'. - - Any expression involving the pointee will be translated to use the -value stored in the pointer as the base address. - - To get the address of elements, this extension provides an intrinsic -function 'LOC()'. The 'LOC()' function is equivalent to the '&' -operator in C, except the address is cast to an integer type: - real ar(10) - pointer(ipt, arpte(10)) - real arpte - ipt = loc(ar) ! Makes arpte is an alias for ar - arpte(1) = 1.0 ! Sets ar(1) to 1.0 - The pointer can also be set by a call to the 'MALLOC' intrinsic (see -*note MALLOC::). - - Cray pointees often are used to alias an existing variable. For -example: - integer target(10) - integer iarr(10) - pointer (ipt, iarr) - ipt = loc(target) - As long as 'ipt' remains unchanged, 'iarr' is now an alias for -'target'. The optimizer, however, will not detect this aliasing, so it -is unsafe to use 'iarr' and 'target' simultaneously. Using a pointee in -any way that violates the Fortran aliasing rules or assumptions is -illegal. It is the user's responsibility to avoid doing this; the -compiler works under the assumption that no such aliasing occurs. - - Cray pointers will work correctly when there is no aliasing (i.e., -when they are used to access a dynamically allocated block of memory), -and also in any routine where a pointee is used, but any variable with -which it shares storage is not used. Code that violates these rules may -not run as the user intends. This is not a bug in the optimizer; any -code that violates the aliasing rules is illegal. (Note that this is -not unique to GNU Fortran; any Fortran compiler that supports Cray -pointers will "incorrectly" optimize code with illegal aliasing.) - - There are a number of restrictions on the attributes that can be -applied to Cray pointers and pointees. Pointees may not have the -'ALLOCATABLE', 'INTENT', 'OPTIONAL', 'DUMMY', 'TARGET', 'INTRINSIC', or -'POINTER' attributes. Pointers may not have the 'DIMENSION', 'POINTER', -'TARGET', 'ALLOCATABLE', 'EXTERNAL', or 'INTRINSIC' attributes, nor may -they be function results. Pointees may not occur in more than one -pointer statement. A pointee cannot be a pointer. Pointees cannot -occur in equivalence, common, or data statements. - - A Cray pointer may also point to a function or a subroutine. For -example, the following excerpt is valid: - implicit none - external sub - pointer (subptr,subpte) - external subpte - subptr = loc(sub) - call subpte() - [...] - subroutine sub - [...] - end subroutine sub - - A pointer may be modified during the course of a program, and this -will change the location to which the pointee refers. However, when -pointees are passed as arguments, they are treated as ordinary variables -in the invoked function. Subsequent changes to the pointer will not -change the base address of the array that was passed. - - -File: gfortran.info, Node: CONVERT specifier, Next: OpenMP, Prev: Cray pointers, Up: Extensions implemented in GNU Fortran - -6.1.15 'CONVERT' specifier --------------------------- - -GNU Fortran allows the conversion of unformatted data between little- -and big-endian representation to facilitate moving of data between -different systems. The conversion can be indicated with the 'CONVERT' -specifier on the 'OPEN' statement. *Note GFORTRAN_CONVERT_UNIT::, for -an alternative way of specifying the data format via an environment -variable. - - Valid values for 'CONVERT' are: - 'CONVERT='NATIVE'' Use the native format. This is the default. - 'CONVERT='SWAP'' Swap between little- and big-endian. - 'CONVERT='LITTLE_ENDIAN'' Use the little-endian representation for - unformatted files. - 'CONVERT='BIG_ENDIAN'' Use the big-endian representation for - unformatted files. - - Using the option could look like this: - open(file='big.dat',form='unformatted',access='sequential', & - convert='big_endian') - - The value of the conversion can be queried by using -'INQUIRE(CONVERT=ch)'. The values returned are ''BIG_ENDIAN'' and -''LITTLE_ENDIAN''. - - 'CONVERT' works between big- and little-endian for 'INTEGER' values -of all supported kinds and for 'REAL' on IEEE systems of kinds 4 and 8. -Conversion between different "extended double" types on different -architectures such as m68k and x86_64, which GNU Fortran supports as -'REAL(KIND=10)' and 'REAL(KIND=16)', will probably not work. - - _Note that the values specified via the GFORTRAN_CONVERT_UNIT -environment variable will override the CONVERT specifier in the open -statement_. This is to give control over data formats to users who do -not have the source code of their program available. - - Using anything but the native representation for unformatted data -carries a significant speed overhead. If speed in this area matters to -you, it is best if you use this only for data that needs to be portable. - - -File: gfortran.info, Node: OpenMP, Next: Argument list functions, Prev: CONVERT specifier, Up: Extensions implemented in GNU Fortran - -6.1.16 OpenMP -------------- - -OpenMP (Open Multi-Processing) is an application programming interface -(API) that supports multi-platform shared memory multiprocessing -programming in C/C++ and Fortran on many architectures, including Unix -and Microsoft Windows platforms. It consists of a set of compiler -directives, library routines, and environment variables that influence -run-time behavior. - - GNU Fortran strives to be compatible to the OpenMP Application -Program Interface v3.1 (http://www.openmp.org/mp-documents/spec31.pdf). - - To enable the processing of the OpenMP directive '!$omp' in free-form -source code; the 'c$omp', '*$omp' and '!$omp' directives in fixed form; -the '!$' conditional compilation sentinels in free form; and the 'c$', -'*$' and '!$' sentinels in fixed form, 'gfortran' needs to be invoked -with the '-fopenmp'. This also arranges for automatic linking of the -GNU OpenMP runtime library *note libgomp: (libgomp)Top. - - The OpenMP Fortran runtime library routines are provided both in a -form of a Fortran 90 module named 'omp_lib' and in a form of a Fortran -'include' file named 'omp_lib.h'. - - An example of a parallelized loop taken from Appendix A.1 of the -OpenMP Application Program Interface v2.5: - SUBROUTINE A1(N, A, B) - INTEGER I, N - REAL B(N), A(N) - !$OMP PARALLEL DO !I is private by default - DO I=2,N - B(I) = (A(I) + A(I-1)) / 2.0 - ENDDO - !$OMP END PARALLEL DO - END SUBROUTINE A1 - - Please note: - * '-fopenmp' implies '-frecursive', i.e., all local arrays will be - allocated on the stack. When porting existing code to OpenMP, this - may lead to surprising results, especially to segmentation faults - if the stacksize is limited. - - * On glibc-based systems, OpenMP enabled applications cannot be - statically linked due to limitations of the underlying - pthreads-implementation. It might be possible to get a working - solution if '-Wl,--whole-archive -lpthread -Wl,--no-whole-archive' - is added to the command line. However, this is not supported by - 'gcc' and thus not recommended. - - -File: gfortran.info, Node: Argument list functions, Prev: OpenMP, Up: Extensions implemented in GNU Fortran - -6.1.17 Argument list functions '%VAL', '%REF' and '%LOC' --------------------------------------------------------- - -GNU Fortran supports argument list functions '%VAL', '%REF' and '%LOC' -statements, for backward compatibility with g77. It is recommended that -these should be used only for code that is accessing facilities outside -of GNU Fortran, such as operating system or windowing facilities. It is -best to constrain such uses to isolated portions of a program-portions -that deal specifically and exclusively with low-level, system-dependent -facilities. Such portions might well provide a portable interface for -use by the program as a whole, but are themselves not portable, and -should be thoroughly tested each time they are rebuilt using a new -compiler or version of a compiler. - - '%VAL' passes a scalar argument by value, '%REF' passes it by -reference and '%LOC' passes its memory location. Since gfortran already -passes scalar arguments by reference, '%REF' is in effect a do-nothing. -'%LOC' has the same effect as a Fortran pointer. - - An example of passing an argument by value to a C subroutine foo.: - C - C prototype void foo_ (float x); - C - external foo - real*4 x - x = 3.14159 - call foo (%VAL (x)) - end - - For details refer to the g77 manual -<http://gcc.gnu.org/onlinedocs/gcc-3.4.6/g77/index.html#Top>. - - Also, 'c_by_val.f' and its partner 'c_by_val.c' of the GNU Fortran -testsuite are worth a look. - - -File: gfortran.info, Node: Extensions not implemented in GNU Fortran, Prev: Extensions implemented in GNU Fortran, Up: Extensions - -6.2 Extensions not implemented in GNU Fortran -============================================= - -The long history of the Fortran language, its wide use and broad -userbase, the large number of different compiler vendors and the lack of -some features crucial to users in the first standards have lead to the -existence of a number of important extensions to the language. While -some of the most useful or popular extensions are supported by the GNU -Fortran compiler, not all existing extensions are supported. This -section aims at listing these extensions and offering advice on how best -make code that uses them running with the GNU Fortran compiler. - -* Menu: - -* STRUCTURE and RECORD:: -* ENCODE and DECODE statements:: -* Variable FORMAT expressions:: -* Alternate complex function syntax:: -* Volatile COMMON blocks:: - - -File: gfortran.info, Node: STRUCTURE and RECORD, Next: ENCODE and DECODE statements, Up: Extensions not implemented in GNU Fortran - -6.2.1 'STRUCTURE' and 'RECORD' ------------------------------- - -Record structures are a pre-Fortran-90 vendor extension to create -user-defined aggregate data types. GNU Fortran does not support record -structures, only Fortran 90's "derived types", which have a different -syntax. - - In many cases, record structures can easily be converted to derived -types. To convert, replace 'STRUCTURE /'STRUCTURE-NAME'/' by 'TYPE' -TYPE-NAME. Additionally, replace 'RECORD /'STRUCTURE-NAME'/' by -'TYPE('TYPE-NAME')'. Finally, in the component access, replace the -period ('.') by the percent sign ('%'). - - Here is an example of code using the non portable record structure -syntax: - - ! Declaring a structure named ``item'' and containing three fields: - ! an integer ID, an description string and a floating-point price. - STRUCTURE /item/ - INTEGER id - CHARACTER(LEN=200) description - REAL price - END STRUCTURE - - ! Define two variables, an single record of type ``item'' - ! named ``pear'', and an array of items named ``store_catalog'' - RECORD /item/ pear, store_catalog(100) - - ! We can directly access the fields of both variables - pear.id = 92316 - pear.description = "juicy D'Anjou pear" - pear.price = 0.15 - store_catalog(7).id = 7831 - store_catalog(7).description = "milk bottle" - store_catalog(7).price = 1.2 - - ! We can also manipulate the whole structure - store_catalog(12) = pear - print *, store_catalog(12) - -This code can easily be rewritten in the Fortran 90 syntax as following: - - ! ``STRUCTURE /name/ ... END STRUCTURE'' becomes - ! ``TYPE name ... END TYPE'' - TYPE item - INTEGER id - CHARACTER(LEN=200) description - REAL price - END TYPE - - ! ``RECORD /name/ variable'' becomes ``TYPE(name) variable'' - TYPE(item) pear, store_catalog(100) - - ! Instead of using a dot (.) to access fields of a record, the - ! standard syntax uses a percent sign (%) - pear%id = 92316 - pear%description = "juicy D'Anjou pear" - pear%price = 0.15 - store_catalog(7)%id = 7831 - store_catalog(7)%description = "milk bottle" - store_catalog(7)%price = 1.2 - - ! Assignments of a whole variable do not change - store_catalog(12) = pear - print *, store_catalog(12) - - -File: gfortran.info, Node: ENCODE and DECODE statements, Next: Variable FORMAT expressions, Prev: STRUCTURE and RECORD, Up: Extensions not implemented in GNU Fortran - -6.2.2 'ENCODE' and 'DECODE' statements --------------------------------------- - -GNU Fortran does not support the 'ENCODE' and 'DECODE' statements. -These statements are best replaced by 'READ' and 'WRITE' statements -involving internal files ('CHARACTER' variables and arrays), which have -been part of the Fortran standard since Fortran 77. For example, -replace a code fragment like - - INTEGER*1 LINE(80) - REAL A, B, C - c ... Code that sets LINE - DECODE (80, 9000, LINE) A, B, C - 9000 FORMAT (1X, 3(F10.5)) - -with the following: - - CHARACTER(LEN=80) LINE - REAL A, B, C - c ... Code that sets LINE - READ (UNIT=LINE, FMT=9000) A, B, C - 9000 FORMAT (1X, 3(F10.5)) - - Similarly, replace a code fragment like - - INTEGER*1 LINE(80) - REAL A, B, C - c ... Code that sets A, B and C - ENCODE (80, 9000, LINE) A, B, C - 9000 FORMAT (1X, 'OUTPUT IS ', 3(F10.5)) - -with the following: - - CHARACTER(LEN=80) LINE - REAL A, B, C - c ... Code that sets A, B and C - WRITE (UNIT=LINE, FMT=9000) A, B, C - 9000 FORMAT (1X, 'OUTPUT IS ', 3(F10.5)) - - -File: gfortran.info, Node: Variable FORMAT expressions, Next: Alternate complex function syntax, Prev: ENCODE and DECODE statements, Up: Extensions not implemented in GNU Fortran - -6.2.3 Variable 'FORMAT' expressions ------------------------------------ - -A variable 'FORMAT' expression is format statement which includes angle -brackets enclosing a Fortran expression: 'FORMAT(I<N>)'. GNU Fortran -does not support this legacy extension. The effect of variable format -expressions can be reproduced by using the more powerful (and standard) -combination of internal output and string formats. For example, replace -a code fragment like this: - - WRITE(6,20) INT1 - 20 FORMAT(I<N+1>) - -with the following: - - c Variable declaration - CHARACTER(LEN=20) FMT - c - c Other code here... - c - WRITE(FMT,'("(I", I0, ")")') N+1 - WRITE(6,FMT) INT1 - -or with: - - c Variable declaration - CHARACTER(LEN=20) FMT - c - c Other code here... - c - WRITE(FMT,*) N+1 - WRITE(6,"(I" // ADJUSTL(FMT) // ")") INT1 - - -File: gfortran.info, Node: Alternate complex function syntax, Next: Volatile COMMON blocks, Prev: Variable FORMAT expressions, Up: Extensions not implemented in GNU Fortran - -6.2.4 Alternate complex function syntax ---------------------------------------- - -Some Fortran compilers, including 'g77', let the user declare complex -functions with the syntax 'COMPLEX FUNCTION name*16()', as well as -'COMPLEX*16 FUNCTION name()'. Both are non-standard, legacy extensions. -'gfortran' accepts the latter form, which is more common, but not the -former. - - -File: gfortran.info, Node: Volatile COMMON blocks, Prev: Alternate complex function syntax, Up: Extensions not implemented in GNU Fortran - -6.2.5 Volatile 'COMMON' blocks ------------------------------- - -Some Fortran compilers, including 'g77', let the user declare 'COMMON' -with the 'VOLATILE' attribute. This is invalid standard Fortran syntax -and is not supported by 'gfortran'. Note that 'gfortran' accepts -'VOLATILE' variables in 'COMMON' blocks since revision 4.3. - - -File: gfortran.info, Node: Mixed-Language Programming, Next: Intrinsic Procedures, Prev: Extensions, Up: Top - -7 Mixed-Language Programming -**************************** - -* Menu: - -* Interoperability with C:: -* GNU Fortran Compiler Directives:: -* Non-Fortran Main Program:: -* Naming and argument-passing conventions:: - -This chapter is about mixed-language interoperability, but also applies -if one links Fortran code compiled by different compilers. In most -cases, use of the C Binding features of the Fortran 2003 standard is -sufficient, and their use is highly recommended. - - -File: gfortran.info, Node: Interoperability with C, Next: GNU Fortran Compiler Directives, Up: Mixed-Language Programming - -7.1 Interoperability with C -=========================== - -* Menu: - -* Intrinsic Types:: -* Derived Types and struct:: -* Interoperable Global Variables:: -* Interoperable Subroutines and Functions:: -* Working with Pointers:: -* Further Interoperability of Fortran with C:: - -Since Fortran 2003 (ISO/IEC 1539-1:2004(E)) there is a standardized way -to generate procedure and derived-type declarations and global variables -which are interoperable with C (ISO/IEC 9899:1999). The 'bind(C)' -attribute has been added to inform the compiler that a symbol shall be -interoperable with C; also, some constraints are added. Note, however, -that not all C features have a Fortran equivalent or vice versa. For -instance, neither C's unsigned integers nor C's functions with variable -number of arguments have an equivalent in Fortran. - - Note that array dimensions are reversely ordered in C and that arrays -in C always start with index 0 while in Fortran they start by default -with 1. Thus, an array declaration 'A(n,m)' in Fortran matches -'A[m][n]' in C and accessing the element 'A(i,j)' matches 'A[j-1][i-1]'. -The element following 'A(i,j)' (C: 'A[j-1][i-1]'; assuming i < n) in -memory is 'A(i+1,j)' (C: 'A[j-1][i]'). - - -File: gfortran.info, Node: Intrinsic Types, Next: Derived Types and struct, Up: Interoperability with C - -7.1.1 Intrinsic Types ---------------------- - -In order to ensure that exactly the same variable type and kind is used -in C and Fortran, the named constants shall be used which are defined in -the 'ISO_C_BINDING' intrinsic module. That module contains named -constants for kind parameters and character named constants for the -escape sequences in C. For a list of the constants, see *note -ISO_C_BINDING::. - - For logical types, please note that the Fortran standard only -guarantees interoperability between C99's '_Bool' and Fortran's -'C_Bool'-kind logicals and C99 defines that 'true' has the value 1 and -'false' the value 0. Using any other integer value with GNU Fortran's -'LOGICAL' (with any kind parameter) gives an undefined result. (Passing -other integer values than 0 and 1 to GCC's '_Bool' is also undefined, -unless the integer is explicitly or implicitly casted to '_Bool'.) - - -File: gfortran.info, Node: Derived Types and struct, Next: Interoperable Global Variables, Prev: Intrinsic Types, Up: Interoperability with C - -7.1.2 Derived Types and struct ------------------------------- - -For compatibility of derived types with 'struct', one needs to use the -'BIND(C)' attribute in the type declaration. For instance, the -following type declaration - - USE ISO_C_BINDING - TYPE, BIND(C) :: myType - INTEGER(C_INT) :: i1, i2 - INTEGER(C_SIGNED_CHAR) :: i3 - REAL(C_DOUBLE) :: d1 - COMPLEX(C_FLOAT_COMPLEX) :: c1 - CHARACTER(KIND=C_CHAR) :: str(5) - END TYPE - - matches the following 'struct' declaration in C - - struct { - int i1, i2; - /* Note: "char" might be signed or unsigned. */ - signed char i3; - double d1; - float _Complex c1; - char str[5]; - } myType; - - Derived types with the C binding attribute shall not have the -'sequence' attribute, type parameters, the 'extends' attribute, nor -type-bound procedures. Every component must be of interoperable type -and kind and may not have the 'pointer' or 'allocatable' attribute. The -names of the components are irrelevant for interoperability. - - As there exist no direct Fortran equivalents, neither unions nor -structs with bit field or variable-length array members are -interoperable. - - -File: gfortran.info, Node: Interoperable Global Variables, Next: Interoperable Subroutines and Functions, Prev: Derived Types and struct, Up: Interoperability with C - -7.1.3 Interoperable Global Variables ------------------------------------- - -Variables can be made accessible from C using the C binding attribute, -optionally together with specifying a binding name. Those variables -have to be declared in the declaration part of a 'MODULE', be of -interoperable type, and have neither the 'pointer' nor the 'allocatable' -attribute. - - MODULE m - USE myType_module - USE ISO_C_BINDING - integer(C_INT), bind(C, name="_MyProject_flags") :: global_flag - type(myType), bind(C) :: tp - END MODULE - - Here, '_MyProject_flags' is the case-sensitive name of the variable -as seen from C programs while 'global_flag' is the case-insensitive name -as seen from Fortran. If no binding name is specified, as for TP, the C -binding name is the (lowercase) Fortran binding name. If a binding name -is specified, only a single variable may be after the double colon. -Note of warning: You cannot use a global variable to access ERRNO of the -C library as the C standard allows it to be a macro. Use the 'IERRNO' -intrinsic (GNU extension) instead. - - -File: gfortran.info, Node: Interoperable Subroutines and Functions, Next: Working with Pointers, Prev: Interoperable Global Variables, Up: Interoperability with C - -7.1.4 Interoperable Subroutines and Functions ---------------------------------------------- - -Subroutines and functions have to have the 'BIND(C)' attribute to be -compatible with C. The dummy argument declaration is relatively -straightforward. However, one needs to be careful because C uses -call-by-value by default while Fortran behaves usually similar to -call-by-reference. Furthermore, strings and pointers are handled -differently. Note that in Fortran 2003 and 2008 only explicit size and -assumed-size arrays are supported but not assumed-shape or -deferred-shape (i.e. allocatable or pointer) arrays. However, those -are allowed since the Technical Specification 29113, see *note Further -Interoperability of Fortran with C:: - - To pass a variable by value, use the 'VALUE' attribute. Thus, the -following C prototype - - int func(int i, int *j) - - matches the Fortran declaration - - integer(c_int) function func(i,j) - use iso_c_binding, only: c_int - integer(c_int), VALUE :: i - integer(c_int) :: j - - Note that pointer arguments also frequently need the 'VALUE' -attribute, see *note Working with Pointers::. - - Strings are handled quite differently in C and Fortran. In C a -string is a 'NUL'-terminated array of characters while in Fortran each -string has a length associated with it and is thus not terminated (by -e.g. 'NUL'). For example, if one wants to use the following C -function, - - #include <stdio.h> - void print_C(char *string) /* equivalent: char string[] */ - { - printf("%s\n", string); - } - - to print "Hello World" from Fortran, one can call it using - - use iso_c_binding, only: C_CHAR, C_NULL_CHAR - interface - subroutine print_c(string) bind(C, name="print_C") - use iso_c_binding, only: c_char - character(kind=c_char) :: string(*) - end subroutine print_c - end interface - call print_c(C_CHAR_"Hello World"//C_NULL_CHAR) - - As the example shows, one needs to ensure that the string is 'NUL' -terminated. Additionally, the dummy argument STRING of 'print_C' is a -length-one assumed-size array; using 'character(len=*)' is not allowed. -The example above uses 'c_char_"Hello World"' to ensure the string -literal has the right type; typically the default character kind and -'c_char' are the same and thus '"Hello World"' is equivalent. However, -the standard does not guarantee this. - - The use of strings is now further illustrated using the C library -function 'strncpy', whose prototype is - - char *strncpy(char *restrict s1, const char *restrict s2, size_t n); - - The function 'strncpy' copies at most N characters from string S2 to -S1 and returns S1. In the following example, we ignore the return -value: - - use iso_c_binding - implicit none - character(len=30) :: str,str2 - interface - ! Ignore the return value of strncpy -> subroutine - ! "restrict" is always assumed if we do not pass a pointer - subroutine strncpy(dest, src, n) bind(C) - import - character(kind=c_char), intent(out) :: dest(*) - character(kind=c_char), intent(in) :: src(*) - integer(c_size_t), value, intent(in) :: n - end subroutine strncpy - end interface - str = repeat('X',30) ! Initialize whole string with 'X' - call strncpy(str, c_char_"Hello World"//C_NULL_CHAR, & - len(c_char_"Hello World",kind=c_size_t)) - print '(a)', str ! prints: "Hello WorldXXXXXXXXXXXXXXXXXXX" - end - - The intrinsic procedures are described in *note Intrinsic -Procedures::. - - -File: gfortran.info, Node: Working with Pointers, Next: Further Interoperability of Fortran with C, Prev: Interoperable Subroutines and Functions, Up: Interoperability with C - -7.1.5 Working with Pointers ---------------------------- - -C pointers are represented in Fortran via the special opaque derived -type 'type(c_ptr)' (with private components). Thus one needs to use -intrinsic conversion procedures to convert from or to C pointers. - - For some applications, using an assumed type ('TYPE(*)') can be an -alternative to a C pointer; see *note Further Interoperability of -Fortran with C::. - - For example, - - use iso_c_binding - type(c_ptr) :: cptr1, cptr2 - integer, target :: array(7), scalar - integer, pointer :: pa(:), ps - cptr1 = c_loc(array(1)) ! The programmer needs to ensure that the - ! array is contiguous if required by the C - ! procedure - cptr2 = c_loc(scalar) - call c_f_pointer(cptr2, ps) - call c_f_pointer(cptr2, pa, shape=[7]) - - When converting C to Fortran arrays, the one-dimensional 'SHAPE' -argument has to be passed. - - If a pointer is a dummy-argument of an interoperable procedure, it -usually has to be declared using the 'VALUE' attribute. 'void*' matches -'TYPE(C_PTR), VALUE', while 'TYPE(C_PTR)' alone matches 'void**'. - - Procedure pointers are handled analogously to pointers; the C type is -'TYPE(C_FUNPTR)' and the intrinsic conversion procedures are -'C_F_PROCPOINTER' and 'C_FUNLOC'. - - Let us consider two examples of actually passing a procedure pointer -from C to Fortran and vice versa. Note that these examples are also -very similar to passing ordinary pointers between both languages. -First, consider this code in C: - - /* Procedure implemented in Fortran. */ - void get_values (void (*)(double)); - - /* Call-back routine we want called from Fortran. */ - void - print_it (double x) - { - printf ("Number is %f.\n", x); - } - - /* Call Fortran routine and pass call-back to it. */ - void - foobar () - { - get_values (&print_it); - } - - A matching implementation for 'get_values' in Fortran, that correctly -receives the procedure pointer from C and is able to call it, is given -in the following 'MODULE': - - MODULE m - IMPLICIT NONE - - ! Define interface of call-back routine. - ABSTRACT INTERFACE - SUBROUTINE callback (x) - USE, INTRINSIC :: ISO_C_BINDING - REAL(KIND=C_DOUBLE), INTENT(IN), VALUE :: x - END SUBROUTINE callback - END INTERFACE - - CONTAINS - - ! Define C-bound procedure. - SUBROUTINE get_values (cproc) BIND(C) - USE, INTRINSIC :: ISO_C_BINDING - TYPE(C_FUNPTR), INTENT(IN), VALUE :: cproc - - PROCEDURE(callback), POINTER :: proc - - ! Convert C to Fortran procedure pointer. - CALL C_F_PROCPOINTER (cproc, proc) - - ! Call it. - CALL proc (1.0_C_DOUBLE) - CALL proc (-42.0_C_DOUBLE) - CALL proc (18.12_C_DOUBLE) - END SUBROUTINE get_values - - END MODULE m - - Next, we want to call a C routine that expects a procedure pointer -argument and pass it a Fortran procedure (which clearly must be -interoperable!). Again, the C function may be: - - int - call_it (int (*func)(int), int arg) - { - return func (arg); - } - - It can be used as in the following Fortran code: - - MODULE m - USE, INTRINSIC :: ISO_C_BINDING - IMPLICIT NONE - - ! Define interface of C function. - INTERFACE - INTEGER(KIND=C_INT) FUNCTION call_it (func, arg) BIND(C) - USE, INTRINSIC :: ISO_C_BINDING - TYPE(C_FUNPTR), INTENT(IN), VALUE :: func - INTEGER(KIND=C_INT), INTENT(IN), VALUE :: arg - END FUNCTION call_it - END INTERFACE - - CONTAINS - - ! Define procedure passed to C function. - ! It must be interoperable! - INTEGER(KIND=C_INT) FUNCTION double_it (arg) BIND(C) - INTEGER(KIND=C_INT), INTENT(IN), VALUE :: arg - double_it = arg + arg - END FUNCTION double_it - - ! Call C function. - SUBROUTINE foobar () - TYPE(C_FUNPTR) :: cproc - INTEGER(KIND=C_INT) :: i - - ! Get C procedure pointer. - cproc = C_FUNLOC (double_it) - - ! Use it. - DO i = 1_C_INT, 10_C_INT - PRINT *, call_it (cproc, i) - END DO - END SUBROUTINE foobar - - END MODULE m - - -File: gfortran.info, Node: Further Interoperability of Fortran with C, Prev: Working with Pointers, Up: Interoperability with C - -7.1.6 Further Interoperability of Fortran with C ------------------------------------------------- - -The Technical Specification ISO/IEC TS 29113:2012 on further -interoperability of Fortran with C extends the interoperability support -of Fortran 2003 and Fortran 2008. Besides removing some restrictions -and constraints, it adds assumed-type ('TYPE(*)') and assumed-rank -('dimension') variables and allows for interoperability of -assumed-shape, assumed-rank and deferred-shape arrays, including -allocatables and pointers. - - Note: Currently, GNU Fortran does not support the array descriptor -(dope vector) as specified in the Technical Specification, but uses an -array descriptor with different fields. The Chasm Language -Interoperability Tools, <http://chasm-interop.sourceforge.net/>, provide -an interface to GNU Fortran's array descriptor. - - The Technical Specification adds the following new features, which -are supported by GNU Fortran: - - * The 'ASYNCHRONOUS' attribute has been clarified and extended to - allow its use with asynchronous communication in user-provided - libraries such as in implementations of the Message Passing - Interface specification. - - * Many constraints have been relaxed, in particular for the 'C_LOC' - and 'C_F_POINTER' intrinsics. - - * The 'OPTIONAL' attribute is now allowed for dummy arguments; an - absent argument matches a 'NULL' pointer. - - * Assumed types ('TYPE(*)') have been added, which may only be used - for dummy arguments. They are unlimited polymorphic but contrary - to 'CLASS(*)' they do not contain any type information, similar to - C's 'void *' pointers. Expressions of any type and kind can be - passed; thus, it can be used as replacement for 'TYPE(C_PTR)', - avoiding the use of 'C_LOC' in the caller. - - Note, however, that 'TYPE(*)' only accepts scalar arguments, unless - the 'DIMENSION' is explicitly specified. As 'DIMENSION(*)' only - supports array (including array elements) but no scalars, it is not - a full replacement for 'C_LOC'. On the other hand, assumed-type - assumed-rank dummy arguments ('TYPE(*), DIMENSION(..)') allow for - both scalars and arrays, but require special code on the callee - side to handle the array descriptor. - - * Assumed-rank arrays ('DIMENSION(..)') as dummy argument allow that - scalars and arrays of any rank can be passed as actual argument. - As the Technical Specification does not provide for direct means to - operate with them, they have to be used either from the C side or - be converted using 'C_LOC' and 'C_F_POINTER' to scalars or arrays - of a specific rank. The rank can be determined using the 'RANK' - intrinisic. - - Currently unimplemented: - - * GNU Fortran always uses an array descriptor, which does not match - the one of the Technical Specification. The - 'ISO_Fortran_binding.h' header file and the C functions it - specifies are not available. - - * Using assumed-shape, assumed-rank and deferred-shape arrays in - 'BIND(C)' procedures is not fully supported. In particular, C - interoperable strings of other length than one are not supported as - this requires the new array descriptor. - - -File: gfortran.info, Node: GNU Fortran Compiler Directives, Next: Non-Fortran Main Program, Prev: Interoperability with C, Up: Mixed-Language Programming - -7.2 GNU Fortran Compiler Directives -=================================== - -The Fortran standard describes how a conforming program shall behave; -however, the exact implementation is not standardized. In order to -allow the user to choose specific implementation details, compiler -directives can be used to set attributes of variables and procedures -which are not part of the standard. Whether a given attribute is -supported and its exact effects depend on both the operating system and -on the processor; see *note C Extensions: (gcc)Top. for details. - - For procedures and procedure pointers, the following attributes can -be used to change the calling convention: - - * 'CDECL' - standard C calling convention - * 'STDCALL' - convention where the called procedure pops the stack - * 'FASTCALL' - part of the arguments are passed via registers instead - using the stack - - Besides changing the calling convention, the attributes also -influence the decoration of the symbol name, e.g., by a leading -underscore or by a trailing at-sign followed by the number of bytes on -the stack. When assigning a procedure to a procedure pointer, both -should use the same calling convention. - - On some systems, procedures and global variables (module variables -and 'COMMON' blocks) need special handling to be accessible when they -are in a shared library. The following attributes are available: - - * 'DLLEXPORT' - provide a global pointer to a pointer in the DLL - * 'DLLIMPORT' - reference the function or variable using a global - pointer - - For dummy arguments, the 'NO_ARG_CHECK' attribute can be used; in -other compilers, it is also known as 'IGNORE_TKR'. For dummy arguments -with this attribute actual arguments of any type and kind (similar to -'TYPE(*)'), scalars and arrays of any rank (no equivalent in Fortran -standard) are accepted. As with 'TYPE(*)', the argument is unlimited -polymorphic and no type information is available. Additionally, the -argument may only be passed to dummy arguments with the 'NO_ARG_CHECK' -attribute and as argument to the 'PRESENT' intrinsic function and to -'C_LOC' of the 'ISO_C_BINDING' module. - - Variables with 'NO_ARG_CHECK' attribute shall be of assumed-type -('TYPE(*)'; recommended) or of type 'INTEGER', 'LOGICAL', 'REAL' or -'COMPLEX'. They shall not have the 'ALLOCATE', 'CODIMENSION', -'INTENT(OUT)', 'POINTER' or 'VALUE' attribute; furthermore, they shall -be either scalar or of assumed-size ('dimension(*)'). As 'TYPE(*)', the -'NO_ARG_CHECK' attribute requires an explicit interface. - - * 'NO_ARG_CHECK' - disable the type, kind and rank checking - - The attributes are specified using the syntax - - '!GCC$ ATTRIBUTES' ATTRIBUTE-LIST '::' VARIABLE-LIST - - where in free-form source code only whitespace is allowed before -'!GCC$' and in fixed-form source code '!GCC$', 'cGCC$' or '*GCC$' shall -start in the first column. - - For procedures, the compiler directives shall be placed into the body -of the procedure; for variables and procedure pointers, they shall be in -the same declaration part as the variable or procedure pointer. - - -File: gfortran.info, Node: Non-Fortran Main Program, Next: Naming and argument-passing conventions, Prev: GNU Fortran Compiler Directives, Up: Mixed-Language Programming - -7.3 Non-Fortran Main Program -============================ - -* Menu: - -* _gfortran_set_args:: Save command-line arguments -* _gfortran_set_options:: Set library option flags -* _gfortran_set_convert:: Set endian conversion -* _gfortran_set_record_marker:: Set length of record markers -* _gfortran_set_fpe:: Set when a Floating Point Exception should be raised -* _gfortran_set_max_subrecord_length:: Set subrecord length - -Even if you are doing mixed-language programming, it is very likely that -you do not need to know or use the information in this section. Since -it is about the internal structure of GNU Fortran, it may also change in -GCC minor releases. - - When you compile a 'PROGRAM' with GNU Fortran, a function with the -name 'main' (in the symbol table of the object file) is generated, which -initializes the libgfortran library and then calls the actual program -which uses the name 'MAIN__', for historic reasons. If you link GNU -Fortran compiled procedures to, e.g., a C or C++ program or to a Fortran -program compiled by a different compiler, the libgfortran library is not -initialized and thus a few intrinsic procedures do not work properly, -e.g. those for obtaining the command-line arguments. - - Therefore, if your 'PROGRAM' is not compiled with GNU Fortran and the -GNU Fortran compiled procedures require intrinsics relying on the -library initialization, you need to initialize the library yourself. -Using the default options, gfortran calls '_gfortran_set_args' and -'_gfortran_set_options'. The initialization of the former is needed if -the called procedures access the command line (and for backtracing); the -latter sets some flags based on the standard chosen or to enable -backtracing. In typical programs, it is not necessary to call any -initialization function. - - If your 'PROGRAM' is compiled with GNU Fortran, you shall not call -any of the following functions. The libgfortran initialization -functions are shown in C syntax but using C bindings they are also -accessible from Fortran. - - -File: gfortran.info, Node: _gfortran_set_args, Next: _gfortran_set_options, Up: Non-Fortran Main Program - -7.3.1 '_gfortran_set_args' -- Save command-line arguments ---------------------------------------------------------- - -_Description_: - '_gfortran_set_args' saves the command-line arguments; this - initialization is required if any of the command-line intrinsics is - called. Additionally, it shall be called if backtracing is enabled - (see '_gfortran_set_options'). - -_Syntax_: - 'void _gfortran_set_args (int argc, char *argv[])' - -_Arguments_: - ARGC number of command line argument strings - ARGV the command-line argument strings; argv[0] is - the pathname of the executable itself. - -_Example_: - int main (int argc, char *argv[]) - { - /* Initialize libgfortran. */ - _gfortran_set_args (argc, argv); - return 0; - } - - -File: gfortran.info, Node: _gfortran_set_options, Next: _gfortran_set_convert, Prev: _gfortran_set_args, Up: Non-Fortran Main Program - -7.3.2 '_gfortran_set_options' -- Set library option flags ---------------------------------------------------------- - -_Description_: - '_gfortran_set_options' sets several flags related to the Fortran - standard to be used, whether backtracing should be enabled and - whether range checks should be performed. The syntax allows for - upward compatibility since the number of passed flags is specified; - for non-passed flags, the default value is used. See also *note - Code Gen Options::. Please note that not all flags are actually - used. - -_Syntax_: - 'void _gfortran_set_options (int num, int options[])' - -_Arguments_: - NUM number of options passed - ARGV The list of flag values - -_option flag list_: - OPTION[0] Allowed standard; can give run-time errors if - e.g. an input-output edit descriptor is invalid - in a given standard. Possible values are - (bitwise or-ed) 'GFC_STD_F77' (1), - 'GFC_STD_F95_OBS' (2), 'GFC_STD_F95_DEL' (4), - 'GFC_STD_F95' (8), 'GFC_STD_F2003' (16), - 'GFC_STD_GNU' (32), 'GFC_STD_LEGACY' (64), - 'GFC_STD_F2008' (128), 'GFC_STD_F2008_OBS' (256) - and GFC_STD_F2008_TS (512). Default: - 'GFC_STD_F95_OBS | GFC_STD_F95_DEL | GFC_STD_F95 - | GFC_STD_F2003 | GFC_STD_F2008 | - GFC_STD_F2008_TS | GFC_STD_F2008_OBS | - GFC_STD_F77 | GFC_STD_GNU | GFC_STD_LEGACY'. - OPTION[1] Standard-warning flag; prints a warning to - standard error. Default: 'GFC_STD_F95_DEL | - GFC_STD_LEGACY'. - OPTION[2] If non zero, enable pedantic checking. Default: - off. - OPTION[3] Unused. - OPTION[4] If non zero, enable backtracing on run-time - errors. Default: off. (Default in the - compiler: on.) Note: Installs a signal handler - and requires command-line initialization using - '_gfortran_set_args'. - OPTION[5] If non zero, supports signed zeros. Default: - enabled. - OPTION[6] Enables run-time checking. Possible values are - (bitwise or-ed): GFC_RTCHECK_BOUNDS (1), - GFC_RTCHECK_ARRAY_TEMPS (2), - GFC_RTCHECK_RECURSION (4), GFC_RTCHECK_DO (16), - GFC_RTCHECK_POINTER (32). Default: disabled. - OPTION[7] Unused. - OPTION[8] Show a warning when invoking 'STOP' and 'ERROR - STOP' if a floating-point exception occurred. - Possible values are (bitwise or-ed) - 'GFC_FPE_INVALID' (1), 'GFC_FPE_DENORMAL' (2), - 'GFC_FPE_ZERO' (4), 'GFC_FPE_OVERFLOW' (8), - 'GFC_FPE_UNDERFLOW' (16), 'GFC_FPE_INEXACT' - (32). Default: None (0). (Default in the - compiler: 'GFC_FPE_INVALID | GFC_FPE_DENORMAL | - GFC_FPE_ZERO | GFC_FPE_OVERFLOW | - GFC_FPE_UNDERFLOW'.) - -_Example_: - /* Use gfortran 4.9 default options. */ - static int options[] = {68, 511, 0, 0, 1, 1, 0, 0, 31}; - _gfortran_set_options (9, &options); - - -File: gfortran.info, Node: _gfortran_set_convert, Next: _gfortran_set_record_marker, Prev: _gfortran_set_options, Up: Non-Fortran Main Program - -7.3.3 '_gfortran_set_convert' -- Set endian conversion ------------------------------------------------------- - -_Description_: - '_gfortran_set_convert' set the representation of data for - unformatted files. - -_Syntax_: - 'void _gfortran_set_convert (int conv)' - -_Arguments_: - CONV Endian conversion, possible values: - GFC_CONVERT_NATIVE (0, default), - GFC_CONVERT_SWAP (1), GFC_CONVERT_BIG (2), - GFC_CONVERT_LITTLE (3). - -_Example_: - int main (int argc, char *argv[]) - { - /* Initialize libgfortran. */ - _gfortran_set_args (argc, argv); - _gfortran_set_convert (1); - return 0; - } - - -File: gfortran.info, Node: _gfortran_set_record_marker, Next: _gfortran_set_fpe, Prev: _gfortran_set_convert, Up: Non-Fortran Main Program - -7.3.4 '_gfortran_set_record_marker' -- Set length of record markers -------------------------------------------------------------------- - -_Description_: - '_gfortran_set_record_marker' sets the length of record markers for - unformatted files. - -_Syntax_: - 'void _gfortran_set_record_marker (int val)' - -_Arguments_: - VAL Length of the record marker; valid values are 4 - and 8. Default is 4. - -_Example_: - int main (int argc, char *argv[]) - { - /* Initialize libgfortran. */ - _gfortran_set_args (argc, argv); - _gfortran_set_record_marker (8); - return 0; - } - - -File: gfortran.info, Node: _gfortran_set_fpe, Next: _gfortran_set_max_subrecord_length, Prev: _gfortran_set_record_marker, Up: Non-Fortran Main Program - -7.3.5 '_gfortran_set_fpe' -- Enable floating point exception traps ------------------------------------------------------------------- - -_Description_: - '_gfortran_set_fpe' enables floating point exception traps for the - specified exceptions. On most systems, this will result in a - SIGFPE signal being sent and the program being aborted. - -_Syntax_: - 'void _gfortran_set_fpe (int val)' - -_Arguments_: - OPTION[0] IEEE exceptions. Possible values are (bitwise - or-ed) zero (0, default) no trapping, - 'GFC_FPE_INVALID' (1), 'GFC_FPE_DENORMAL' (2), - 'GFC_FPE_ZERO' (4), 'GFC_FPE_OVERFLOW' (8), - 'GFC_FPE_UNDERFLOW' (16), and 'GFC_FPE_INEXACT' - (32). - -_Example_: - int main (int argc, char *argv[]) - { - /* Initialize libgfortran. */ - _gfortran_set_args (argc, argv); - /* FPE for invalid operations such as SQRT(-1.0). */ - _gfortran_set_fpe (1); - return 0; - } - - -File: gfortran.info, Node: _gfortran_set_max_subrecord_length, Prev: _gfortran_set_fpe, Up: Non-Fortran Main Program - -7.3.6 '_gfortran_set_max_subrecord_length' -- Set subrecord length ------------------------------------------------------------------- - -_Description_: - '_gfortran_set_max_subrecord_length' set the maximum length for a - subrecord. This option only makes sense for testing and debugging - of unformatted I/O. - -_Syntax_: - 'void _gfortran_set_max_subrecord_length (int val)' - -_Arguments_: - VAL the maximum length for a subrecord; the maximum - permitted value is 2147483639, which is also the - default. - -_Example_: - int main (int argc, char *argv[]) - { - /* Initialize libgfortran. */ - _gfortran_set_args (argc, argv); - _gfortran_set_max_subrecord_length (8); - return 0; - } - - -File: gfortran.info, Node: Naming and argument-passing conventions, Prev: Non-Fortran Main Program, Up: Mixed-Language Programming - -7.4 Naming and argument-passing conventions -=========================================== - -This section gives an overview about the naming convention of procedures -and global variables and about the argument passing conventions used by -GNU Fortran. If a C binding has been specified, the naming convention -and some of the argument-passing conventions change. If possible, -mixed-language and mixed-compiler projects should use the better defined -C binding for interoperability. See *note Interoperability with C::. - -* Menu: - -* Naming conventions:: -* Argument passing conventions:: - - -File: gfortran.info, Node: Naming conventions, Next: Argument passing conventions, Up: Naming and argument-passing conventions - -7.4.1 Naming conventions ------------------------- - -According the Fortran standard, valid Fortran names consist of a letter -between 'A' to 'Z', 'a' to 'z', digits '0', '1' to '9' and underscores -('_') with the restriction that names may only start with a letter. As -vendor extension, the dollar sign ('$') is additionally permitted with -the option '-fdollar-ok', but not as first character and only if the -target system supports it. - - By default, the procedure name is the lower-cased Fortran name with -an appended underscore ('_'); using '-fno-underscoring' no underscore is -appended while '-fsecond-underscore' appends two underscores. Depending -on the target system and the calling convention, the procedure might be -additionally dressed; for instance, on 32bit Windows with 'stdcall', an -at-sign '@' followed by an integer number is appended. For the changing -the calling convention, see *note GNU Fortran Compiler Directives::. - - For common blocks, the same convention is used, i.e. by default an -underscore is appended to the lower-cased Fortran name. Blank commons -have the name '__BLNK__'. - - For procedures and variables declared in the specification space of a -module, the name is formed by '__', followed by the lower-cased module -name, '_MOD_', and the lower-cased Fortran name. Note that no -underscore is appended. - - -File: gfortran.info, Node: Argument passing conventions, Prev: Naming conventions, Up: Naming and argument-passing conventions - -7.4.2 Argument passing conventions ----------------------------------- - -Subroutines do not return a value (matching C99's 'void') while -functions either return a value as specified in the platform ABI or the -result variable is passed as hidden argument to the function and no -result is returned. A hidden result variable is used when the result -variable is an array or of type 'CHARACTER'. - - Arguments are passed according to the platform ABI. In particular, -complex arguments might not be compatible to a struct with two real -components for the real and imaginary part. The argument passing -matches the one of C99's '_Complex'. Functions with scalar complex -result variables return their value and do not use a by-reference -argument. Note that with the '-ff2c' option, the argument passing is -modified and no longer completely matches the platform ABI. Some other -Fortran compilers use 'f2c' semantic by default; this might cause -problems with interoperablility. - - GNU Fortran passes most arguments by reference, i.e. by passing a -pointer to the data. Note that the compiler might use a temporary -variable into which the actual argument has been copied, if required -semantically (copy-in/copy-out). - - For arguments with 'ALLOCATABLE' and 'POINTER' attribute (including -procedure pointers), a pointer to the pointer is passed such that the -pointer address can be modified in the procedure. - - For dummy arguments with the 'VALUE' attribute: Scalar arguments of -the type 'INTEGER', 'LOGICAL', 'REAL' and 'COMPLEX' are passed by value -according to the platform ABI. (As vendor extension and not recommended, -using '%VAL()' in the call to a procedure has the same effect.) For -'TYPE(C_PTR)' and procedure pointers, the pointer itself is passed such -that it can be modified without affecting the caller. - - For Boolean ('LOGICAL') arguments, please note that GCC expects only -the integer value 0 and 1. If a GNU Fortran 'LOGICAL' variable contains -another integer value, the result is undefined. As some other Fortran -compilers use -1 for '.TRUE.', extra care has to be taken - such as -passing the value as 'INTEGER'. (The same value restriction also -applies to other front ends of GCC, e.g. to GCC's C99 compiler for -'_Bool' or GCC's Ada compiler for 'Boolean'.) - - For arguments of 'CHARACTER' type, the character length is passed as -hidden argument. For deferred-length strings, the value is passed by -reference, otherwise by value. The character length has the type -'INTEGER(kind=4)'. Note with C binding, 'CHARACTER(len=1)' result -variables are returned according to the platform ABI and no hidden -length argument is used for dummy arguments; with 'VALUE', those -variables are passed by value. - - For 'OPTIONAL' dummy arguments, an absent argument is denoted by a -NULL pointer, except for scalar dummy arguments of type 'INTEGER', -'LOGICAL', 'REAL' and 'COMPLEX' which have the 'VALUE' attribute. For -those, a hidden Boolean argument ('logical(kind=C_bool),value') is used -to indicate whether the argument is present. - - Arguments which are assumed-shape, assumed-rank or deferred-rank -arrays or, with '-fcoarray=lib', allocatable scalar coarrays use an -array descriptor. All other arrays pass the address of the first -element of the array. With '-fcoarray=lib', the token and the offset -belonging to nonallocatable coarrays dummy arguments are passed as -hidden argument along the character length hidden arguments. The token -is an oparque pointer identifying the coarray and the offset is a -passed-by-value integer of kind 'C_PTRDIFF_T', denoting the byte offset -between the base address of the coarray and the passed scalar or first -element of the passed array. - - The arguments are passed in the following order - * Result variable, when the function result is passed by reference - * Character length of the function result, if it is a of type - 'CHARACTER' and no C binding is used - * The arguments in the order in which they appear in the Fortran - declaration - * The the present status for optional arguments with value attribute, - which are internally passed by value - * The character length and/or coarray token and offset for the first - argument which is a 'CHARACTER' or a nonallocatable coarray dummy - argument, followed by the hidden arguments of the next dummy - argument of such a type - - -File: gfortran.info, Node: Intrinsic Procedures, Next: Intrinsic Modules, Prev: Mixed-Language Programming, Up: Top - -8 Intrinsic Procedures -********************** - -* Menu: - -* Introduction: Introduction to Intrinsics -* 'ABORT': ABORT, Abort the program -* 'ABS': ABS, Absolute value -* 'ACCESS': ACCESS, Checks file access modes -* 'ACHAR': ACHAR, Character in ASCII collating sequence -* 'ACOS': ACOS, Arccosine function -* 'ACOSH': ACOSH, Inverse hyperbolic cosine function -* 'ADJUSTL': ADJUSTL, Left adjust a string -* 'ADJUSTR': ADJUSTR, Right adjust a string -* 'AIMAG': AIMAG, Imaginary part of complex number -* 'AINT': AINT, Truncate to a whole number -* 'ALARM': ALARM, Set an alarm clock -* 'ALL': ALL, Determine if all values are true -* 'ALLOCATED': ALLOCATED, Status of allocatable entity -* 'AND': AND, Bitwise logical AND -* 'ANINT': ANINT, Nearest whole number -* 'ANY': ANY, Determine if any values are true -* 'ASIN': ASIN, Arcsine function -* 'ASINH': ASINH, Inverse hyperbolic sine function -* 'ASSOCIATED': ASSOCIATED, Status of a pointer or pointer/target pair -* 'ATAN': ATAN, Arctangent function -* 'ATAN2': ATAN2, Arctangent function -* 'ATANH': ATANH, Inverse hyperbolic tangent function -* 'ATOMIC_DEFINE': ATOMIC_DEFINE, Setting a variable atomically -* 'ATOMIC_REF': ATOMIC_REF, Obtaining the value of a variable atomically -* 'BACKTRACE': BACKTRACE, Show a backtrace -* 'BESSEL_J0': BESSEL_J0, Bessel function of the first kind of order 0 -* 'BESSEL_J1': BESSEL_J1, Bessel function of the first kind of order 1 -* 'BESSEL_JN': BESSEL_JN, Bessel function of the first kind -* 'BESSEL_Y0': BESSEL_Y0, Bessel function of the second kind of order 0 -* 'BESSEL_Y1': BESSEL_Y1, Bessel function of the second kind of order 1 -* 'BESSEL_YN': BESSEL_YN, Bessel function of the second kind -* 'BGE': BGE, Bitwise greater than or equal to -* 'BGT': BGT, Bitwise greater than -* 'BIT_SIZE': BIT_SIZE, Bit size inquiry function -* 'BLE': BLE, Bitwise less than or equal to -* 'BLT': BLT, Bitwise less than -* 'BTEST': BTEST, Bit test function -* 'C_ASSOCIATED': C_ASSOCIATED, Status of a C pointer -* 'C_F_POINTER': C_F_POINTER, Convert C into Fortran pointer -* 'C_F_PROCPOINTER': C_F_PROCPOINTER, Convert C into Fortran procedure pointer -* 'C_FUNLOC': C_FUNLOC, Obtain the C address of a procedure -* 'C_LOC': C_LOC, Obtain the C address of an object -* 'C_SIZEOF': C_SIZEOF, Size in bytes of an expression -* 'CEILING': CEILING, Integer ceiling function -* 'CHAR': CHAR, Integer-to-character conversion function -* 'CHDIR': CHDIR, Change working directory -* 'CHMOD': CHMOD, Change access permissions of files -* 'CMPLX': CMPLX, Complex conversion function -* 'COMMAND_ARGUMENT_COUNT': COMMAND_ARGUMENT_COUNT, Get number of command line arguments -* 'COMPILER_OPTIONS': COMPILER_OPTIONS, Options passed to the compiler -* 'COMPILER_VERSION': COMPILER_VERSION, Compiler version string -* 'COMPLEX': COMPLEX, Complex conversion function -* 'CONJG': CONJG, Complex conjugate function -* 'COS': COS, Cosine function -* 'COSH': COSH, Hyperbolic cosine function -* 'COUNT': COUNT, Count occurrences of TRUE in an array -* 'CPU_TIME': CPU_TIME, CPU time subroutine -* 'CSHIFT': CSHIFT, Circular shift elements of an array -* 'CTIME': CTIME, Subroutine (or function) to convert a time into a string -* 'DATE_AND_TIME': DATE_AND_TIME, Date and time subroutine -* 'DBLE': DBLE, Double precision conversion function -* 'DCMPLX': DCMPLX, Double complex conversion function -* 'DIGITS': DIGITS, Significant digits function -* 'DIM': DIM, Positive difference -* 'DOT_PRODUCT': DOT_PRODUCT, Dot product function -* 'DPROD': DPROD, Double product function -* 'DREAL': DREAL, Double real part function -* 'DSHIFTL': DSHIFTL, Combined left shift -* 'DSHIFTR': DSHIFTR, Combined right shift -* 'DTIME': DTIME, Execution time subroutine (or function) -* 'EOSHIFT': EOSHIFT, End-off shift elements of an array -* 'EPSILON': EPSILON, Epsilon function -* 'ERF': ERF, Error function -* 'ERFC': ERFC, Complementary error function -* 'ERFC_SCALED': ERFC_SCALED, Exponentially-scaled complementary error function -* 'ETIME': ETIME, Execution time subroutine (or function) -* 'EXECUTE_COMMAND_LINE': EXECUTE_COMMAND_LINE, Execute a shell command -* 'EXIT': EXIT, Exit the program with status. -* 'EXP': EXP, Exponential function -* 'EXPONENT': EXPONENT, Exponent function -* 'EXTENDS_TYPE_OF': EXTENDS_TYPE_OF, Query dynamic type for extension -* 'FDATE': FDATE, Subroutine (or function) to get the current time as a string -* 'FGET': FGET, Read a single character in stream mode from stdin -* 'FGETC': FGETC, Read a single character in stream mode -* 'FLOOR': FLOOR, Integer floor function -* 'FLUSH': FLUSH, Flush I/O unit(s) -* 'FNUM': FNUM, File number function -* 'FPUT': FPUT, Write a single character in stream mode to stdout -* 'FPUTC': FPUTC, Write a single character in stream mode -* 'FRACTION': FRACTION, Fractional part of the model representation -* 'FREE': FREE, Memory de-allocation subroutine -* 'FSEEK': FSEEK, Low level file positioning subroutine -* 'FSTAT': FSTAT, Get file status -* 'FTELL': FTELL, Current stream position -* 'GAMMA': GAMMA, Gamma function -* 'GERROR': GERROR, Get last system error message -* 'GETARG': GETARG, Get command line arguments -* 'GET_COMMAND': GET_COMMAND, Get the entire command line -* 'GET_COMMAND_ARGUMENT': GET_COMMAND_ARGUMENT, Get command line arguments -* 'GETCWD': GETCWD, Get current working directory -* 'GETENV': GETENV, Get an environmental variable -* 'GET_ENVIRONMENT_VARIABLE': GET_ENVIRONMENT_VARIABLE, Get an environmental variable -* 'GETGID': GETGID, Group ID function -* 'GETLOG': GETLOG, Get login name -* 'GETPID': GETPID, Process ID function -* 'GETUID': GETUID, User ID function -* 'GMTIME': GMTIME, Convert time to GMT info -* 'HOSTNM': HOSTNM, Get system host name -* 'HUGE': HUGE, Largest number of a kind -* 'HYPOT': HYPOT, Euclidean distance function -* 'IACHAR': IACHAR, Code in ASCII collating sequence -* 'IALL': IALL, Bitwise AND of array elements -* 'IAND': IAND, Bitwise logical and -* 'IANY': IANY, Bitwise OR of array elements -* 'IARGC': IARGC, Get the number of command line arguments -* 'IBCLR': IBCLR, Clear bit -* 'IBITS': IBITS, Bit extraction -* 'IBSET': IBSET, Set bit -* 'ICHAR': ICHAR, Character-to-integer conversion function -* 'IDATE': IDATE, Current local time (day/month/year) -* 'IEOR': IEOR, Bitwise logical exclusive or -* 'IERRNO': IERRNO, Function to get the last system error number -* 'IMAGE_INDEX': IMAGE_INDEX, Cosubscript to image index conversion -* 'INDEX': INDEX intrinsic, Position of a substring within a string -* 'INT': INT, Convert to integer type -* 'INT2': INT2, Convert to 16-bit integer type -* 'INT8': INT8, Convert to 64-bit integer type -* 'IOR': IOR, Bitwise logical or -* 'IPARITY': IPARITY, Bitwise XOR of array elements -* 'IRAND': IRAND, Integer pseudo-random number -* 'IS_IOSTAT_END': IS_IOSTAT_END, Test for end-of-file value -* 'IS_IOSTAT_EOR': IS_IOSTAT_EOR, Test for end-of-record value -* 'ISATTY': ISATTY, Whether a unit is a terminal device -* 'ISHFT': ISHFT, Shift bits -* 'ISHFTC': ISHFTC, Shift bits circularly -* 'ISNAN': ISNAN, Tests for a NaN -* 'ITIME': ITIME, Current local time (hour/minutes/seconds) -* 'KILL': KILL, Send a signal to a process -* 'KIND': KIND, Kind of an entity -* 'LBOUND': LBOUND, Lower dimension bounds of an array -* 'LCOBOUND': LCOBOUND, Lower codimension bounds of an array -* 'LEADZ': LEADZ, Number of leading zero bits of an integer -* 'LEN': LEN, Length of a character entity -* 'LEN_TRIM': LEN_TRIM, Length of a character entity without trailing blank characters -* 'LGE': LGE, Lexical greater than or equal -* 'LGT': LGT, Lexical greater than -* 'LINK': LINK, Create a hard link -* 'LLE': LLE, Lexical less than or equal -* 'LLT': LLT, Lexical less than -* 'LNBLNK': LNBLNK, Index of the last non-blank character in a string -* 'LOC': LOC, Returns the address of a variable -* 'LOG': LOG, Logarithm function -* 'LOG10': LOG10, Base 10 logarithm function -* 'LOG_GAMMA': LOG_GAMMA, Logarithm of the Gamma function -* 'LOGICAL': LOGICAL, Convert to logical type -* 'LONG': LONG, Convert to integer type -* 'LSHIFT': LSHIFT, Left shift bits -* 'LSTAT': LSTAT, Get file status -* 'LTIME': LTIME, Convert time to local time info -* 'MALLOC': MALLOC, Dynamic memory allocation function -* 'MASKL': MASKL, Left justified mask -* 'MASKR': MASKR, Right justified mask -* 'MATMUL': MATMUL, matrix multiplication -* 'MAX': MAX, Maximum value of an argument list -* 'MAXEXPONENT': MAXEXPONENT, Maximum exponent of a real kind -* 'MAXLOC': MAXLOC, Location of the maximum value within an array -* 'MAXVAL': MAXVAL, Maximum value of an array -* 'MCLOCK': MCLOCK, Time function -* 'MCLOCK8': MCLOCK8, Time function (64-bit) -* 'MERGE': MERGE, Merge arrays -* 'MERGE_BITS': MERGE_BITS, Merge of bits under mask -* 'MIN': MIN, Minimum value of an argument list -* 'MINEXPONENT': MINEXPONENT, Minimum exponent of a real kind -* 'MINLOC': MINLOC, Location of the minimum value within an array -* 'MINVAL': MINVAL, Minimum value of an array -* 'MOD': MOD, Remainder function -* 'MODULO': MODULO, Modulo function -* 'MOVE_ALLOC': MOVE_ALLOC, Move allocation from one object to another -* 'MVBITS': MVBITS, Move bits from one integer to another -* 'NEAREST': NEAREST, Nearest representable number -* 'NEW_LINE': NEW_LINE, New line character -* 'NINT': NINT, Nearest whole number -* 'NORM2': NORM2, Euclidean vector norm -* 'NOT': NOT, Logical negation -* 'NULL': NULL, Function that returns an disassociated pointer -* 'NUM_IMAGES': NUM_IMAGES, Number of images -* 'OR': OR, Bitwise logical OR -* 'PACK': PACK, Pack an array into an array of rank one -* 'PARITY': PARITY, Reduction with exclusive OR -* 'PERROR': PERROR, Print system error message -* 'POPCNT': POPCNT, Number of bits set -* 'POPPAR': POPPAR, Parity of the number of bits set -* 'PRECISION': PRECISION, Decimal precision of a real kind -* 'PRESENT': PRESENT, Determine whether an optional dummy argument is specified -* 'PRODUCT': PRODUCT, Product of array elements -* 'RADIX': RADIX, Base of a data model -* 'RAN': RAN, Real pseudo-random number -* 'RAND': RAND, Real pseudo-random number -* 'RANDOM_NUMBER': RANDOM_NUMBER, Pseudo-random number -* 'RANDOM_SEED': RANDOM_SEED, Initialize a pseudo-random number sequence -* 'RANGE': RANGE, Decimal exponent range -* 'RANK' : RANK, Rank of a data object -* 'REAL': REAL, Convert to real type -* 'RENAME': RENAME, Rename a file -* 'REPEAT': REPEAT, Repeated string concatenation -* 'RESHAPE': RESHAPE, Function to reshape an array -* 'RRSPACING': RRSPACING, Reciprocal of the relative spacing -* 'RSHIFT': RSHIFT, Right shift bits -* 'SAME_TYPE_AS': SAME_TYPE_AS, Query dynamic types for equality -* 'SCALE': SCALE, Scale a real value -* 'SCAN': SCAN, Scan a string for the presence of a set of characters -* 'SECNDS': SECNDS, Time function -* 'SECOND': SECOND, CPU time function -* 'SELECTED_CHAR_KIND': SELECTED_CHAR_KIND, Choose character kind -* 'SELECTED_INT_KIND': SELECTED_INT_KIND, Choose integer kind -* 'SELECTED_REAL_KIND': SELECTED_REAL_KIND, Choose real kind -* 'SET_EXPONENT': SET_EXPONENT, Set the exponent of the model -* 'SHAPE': SHAPE, Determine the shape of an array -* 'SHIFTA': SHIFTA, Right shift with fill -* 'SHIFTL': SHIFTL, Left shift -* 'SHIFTR': SHIFTR, Right shift -* 'SIGN': SIGN, Sign copying function -* 'SIGNAL': SIGNAL, Signal handling subroutine (or function) -* 'SIN': SIN, Sine function -* 'SINH': SINH, Hyperbolic sine function -* 'SIZE': SIZE, Function to determine the size of an array -* 'SIZEOF': SIZEOF, Determine the size in bytes of an expression -* 'SLEEP': SLEEP, Sleep for the specified number of seconds -* 'SPACING': SPACING, Smallest distance between two numbers of a given type -* 'SPREAD': SPREAD, Add a dimension to an array -* 'SQRT': SQRT, Square-root function -* 'SRAND': SRAND, Reinitialize the random number generator -* 'STAT': STAT, Get file status -* 'STORAGE_SIZE': STORAGE_SIZE, Storage size in bits -* 'SUM': SUM, Sum of array elements -* 'SYMLNK': SYMLNK, Create a symbolic link -* 'SYSTEM': SYSTEM, Execute a shell command -* 'SYSTEM_CLOCK': SYSTEM_CLOCK, Time function -* 'TAN': TAN, Tangent function -* 'TANH': TANH, Hyperbolic tangent function -* 'THIS_IMAGE': THIS_IMAGE, Cosubscript index of this image -* 'TIME': TIME, Time function -* 'TIME8': TIME8, Time function (64-bit) -* 'TINY': TINY, Smallest positive number of a real kind -* 'TRAILZ': TRAILZ, Number of trailing zero bits of an integer -* 'TRANSFER': TRANSFER, Transfer bit patterns -* 'TRANSPOSE': TRANSPOSE, Transpose an array of rank two -* 'TRIM': TRIM, Remove trailing blank characters of a string -* 'TTYNAM': TTYNAM, Get the name of a terminal device. -* 'UBOUND': UBOUND, Upper dimension bounds of an array -* 'UCOBOUND': UCOBOUND, Upper codimension bounds of an array -* 'UMASK': UMASK, Set the file creation mask -* 'UNLINK': UNLINK, Remove a file from the file system -* 'UNPACK': UNPACK, Unpack an array of rank one into an array -* 'VERIFY': VERIFY, Scan a string for the absence of a set of characters -* 'XOR': XOR, Bitwise logical exclusive or - - -File: gfortran.info, Node: Introduction to Intrinsics, Next: ABORT, Up: Intrinsic Procedures - -8.1 Introduction to intrinsic procedures -======================================== - -The intrinsic procedures provided by GNU Fortran include all of the -intrinsic procedures required by the Fortran 95 standard, a set of -intrinsic procedures for backwards compatibility with G77, and a -selection of intrinsic procedures from the Fortran 2003 and Fortran 2008 -standards. Any conflict between a description here and a description in -either the Fortran 95 standard, the Fortran 2003 standard or the Fortran -2008 standard is unintentional, and the standard(s) should be considered -authoritative. - - The enumeration of the 'KIND' type parameter is processor defined in -the Fortran 95 standard. GNU Fortran defines the default integer type -and default real type by 'INTEGER(KIND=4)' and 'REAL(KIND=4)', -respectively. The standard mandates that both data types shall have -another kind, which have more precision. On typical target -architectures supported by 'gfortran', this kind type parameter is -'KIND=8'. Hence, 'REAL(KIND=8)' and 'DOUBLE PRECISION' are equivalent. -In the description of generic intrinsic procedures, the kind type -parameter will be specified by 'KIND=*', and in the description of -specific names for an intrinsic procedure the kind type parameter will -be explicitly given (e.g., 'REAL(KIND=4)' or 'REAL(KIND=8)'). Finally, -for brevity the optional 'KIND=' syntax will be omitted. - - Many of the intrinsic procedures take one or more optional arguments. -This document follows the convention used in the Fortran 95 standard, -and denotes such arguments by square brackets. - - GNU Fortran offers the '-std=f95' and '-std=gnu' options, which can -be used to restrict the set of intrinsic procedures to a given standard. -By default, 'gfortran' sets the '-std=gnu' option, and so all intrinsic -procedures described here are accepted. There is one caveat. For a -select group of intrinsic procedures, 'g77' implemented both a function -and a subroutine. Both classes have been implemented in 'gfortran' for -backwards compatibility with 'g77'. It is noted here that these -functions and subroutines cannot be intermixed in a given subprogram. -In the descriptions that follow, the applicable standard for each -intrinsic procedure is noted. - - -File: gfortran.info, Node: ABORT, Next: ABS, Prev: Introduction to Intrinsics, Up: Intrinsic Procedures - -8.2 'ABORT' -- Abort the program -================================ - -_Description_: - 'ABORT' causes immediate termination of the program. On operating - systems that support a core dump, 'ABORT' will produce a core dump. - It will also print a backtrace, unless '-fno-backtrace' is given. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL ABORT' - -_Return value_: - Does not return. - -_Example_: - program test_abort - integer :: i = 1, j = 2 - if (i /= j) call abort - end program test_abort - -_See also_: - *note EXIT::, *note KILL::, *note BACKTRACE:: - - -File: gfortran.info, Node: ABS, Next: ACCESS, Prev: ABORT, Up: Intrinsic Procedures - -8.3 'ABS' -- Absolute value -=========================== - -_Description_: - 'ABS(A)' computes the absolute value of 'A'. - -_Standard_: - Fortran 77 and later, has overloads that are GNU extensions - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ABS(A)' - -_Arguments_: - A The type of the argument shall be an 'INTEGER', - 'REAL', or 'COMPLEX'. - -_Return value_: - The return value is of the same type and kind as the argument - except the return value is 'REAL' for a 'COMPLEX' argument. - -_Example_: - program test_abs - integer :: i = -1 - real :: x = -1.e0 - complex :: z = (-1.e0,0.e0) - i = abs(i) - x = abs(x) - x = abs(z) - end program test_abs - -_Specific names_: - Name Argument Return type Standard - 'ABS(A)' 'REAL(4) A' 'REAL(4)' Fortran 77 and - later - 'CABS(A)' 'COMPLEX(4) 'REAL(4)' Fortran 77 and - A' later - 'DABS(A)' 'REAL(8) A' 'REAL(8)' Fortran 77 and - later - 'IABS(A)' 'INTEGER(4) 'INTEGER(4)' Fortran 77 and - A' later - 'ZABS(A)' 'COMPLEX(8) 'COMPLEX(8)' GNU extension - A' - 'CDABS(A)' 'COMPLEX(8) 'COMPLEX(8)' GNU extension - A' - - -File: gfortran.info, Node: ACCESS, Next: ACHAR, Prev: ABS, Up: Intrinsic Procedures - -8.4 'ACCESS' -- Checks file access modes -======================================== - -_Description_: - 'ACCESS(NAME, MODE)' checks whether the file NAME exists, is - readable, writable or executable. Except for the executable check, - 'ACCESS' can be replaced by Fortran 95's 'INQUIRE'. - -_Standard_: - GNU extension - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = ACCESS(NAME, MODE)' - -_Arguments_: - NAME Scalar 'CHARACTER' of default kind with the file - name. Tailing blank are ignored unless the - character 'achar(0)' is present, then all - characters up to and excluding 'achar(0)' are - used as file name. - MODE Scalar 'CHARACTER' of default kind with the file - access mode, may be any concatenation of '"r"' - (readable), '"w"' (writable) and '"x"' - (executable), or '" "' to check for existence. - -_Return value_: - Returns a scalar 'INTEGER', which is '0' if the file is accessible - in the given mode; otherwise or if an invalid argument has been - given for 'MODE' the value '1' is returned. - -_Example_: - program access_test - implicit none - character(len=*), parameter :: file = 'test.dat' - character(len=*), parameter :: file2 = 'test.dat '//achar(0) - if(access(file,' ') == 0) print *, trim(file),' is exists' - if(access(file,'r') == 0) print *, trim(file),' is readable' - if(access(file,'w') == 0) print *, trim(file),' is writable' - if(access(file,'x') == 0) print *, trim(file),' is executable' - if(access(file2,'rwx') == 0) & - print *, trim(file2),' is readable, writable and executable' - end program access_test -_Specific names_: -_See also_: - - -File: gfortran.info, Node: ACHAR, Next: ACOS, Prev: ACCESS, Up: Intrinsic Procedures - -8.5 'ACHAR' -- Character in ASCII collating sequence -==================================================== - -_Description_: - 'ACHAR(I)' returns the character located at position 'I' in the - ASCII collating sequence. - -_Standard_: - Fortran 77 and later, with KIND argument Fortran 2003 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ACHAR(I [, KIND])' - -_Arguments_: - I The type shall be 'INTEGER'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'CHARACTER' with a length of one. If - the KIND argument is present, the return value is of the specified - kind and of the default kind otherwise. - -_Example_: - program test_achar - character c - c = achar(32) - end program test_achar - -_Note_: - See *note ICHAR:: for a discussion of converting between numerical - values and formatted string representations. - -_See also_: - *note CHAR::, *note IACHAR::, *note ICHAR:: - - -File: gfortran.info, Node: ACOS, Next: ACOSH, Prev: ACHAR, Up: Intrinsic Procedures - -8.6 'ACOS' -- Arccosine function -================================ - -_Description_: - 'ACOS(X)' computes the arccosine of X (inverse of 'COS(X)'). - -_Standard_: - Fortran 77 and later, for a complex argument Fortran 2008 or later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ACOS(X)' - -_Arguments_: - X The type shall either be 'REAL' with a magnitude - that is less than or equal to one - or the type - shall be 'COMPLEX'. - -_Return value_: - The return value is of the same type and kind as X. The real part - of the result is in radians and lies in the range 0 \leq \Re - \acos(x) \leq \pi. - -_Example_: - program test_acos - real(8) :: x = 0.866_8 - x = acos(x) - end program test_acos - -_Specific names_: - Name Argument Return type Standard - 'ACOS(X)' 'REAL(4) X' 'REAL(4)' Fortran 77 and - later - 'DACOS(X)' 'REAL(8) X' 'REAL(8)' Fortran 77 and - later - -_See also_: - Inverse function: *note COS:: - - -File: gfortran.info, Node: ACOSH, Next: ADJUSTL, Prev: ACOS, Up: Intrinsic Procedures - -8.7 'ACOSH' -- Inverse hyperbolic cosine function -================================================= - -_Description_: - 'ACOSH(X)' computes the inverse hyperbolic cosine of X. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ACOSH(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value has the same type and kind as X. If X is complex, - the imaginary part of the result is in radians and lies between 0 - \leq \Im \acosh(x) \leq \pi. - -_Example_: - PROGRAM test_acosh - REAL(8), DIMENSION(3) :: x = (/ 1.0, 2.0, 3.0 /) - WRITE (*,*) ACOSH(x) - END PROGRAM - -_Specific names_: - Name Argument Return type Standard - 'DACOSH(X)' 'REAL(8) X' 'REAL(8)' GNU extension - -_See also_: - Inverse function: *note COSH:: - - -File: gfortran.info, Node: ADJUSTL, Next: ADJUSTR, Prev: ACOSH, Up: Intrinsic Procedures - -8.8 'ADJUSTL' -- Left adjust a string -===================================== - -_Description_: - 'ADJUSTL(STRING)' will left adjust a string by removing leading - spaces. Spaces are inserted at the end of the string as needed. - -_Standard_: - Fortran 90 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ADJUSTL(STRING)' - -_Arguments_: - STRING The type shall be 'CHARACTER'. - -_Return value_: - The return value is of type 'CHARACTER' and of the same kind as - STRING where leading spaces are removed and the same number of - spaces are inserted on the end of STRING. - -_Example_: - program test_adjustl - character(len=20) :: str = ' gfortran' - str = adjustl(str) - print *, str - end program test_adjustl - -_See also_: - *note ADJUSTR::, *note TRIM:: - - -File: gfortran.info, Node: ADJUSTR, Next: AIMAG, Prev: ADJUSTL, Up: Intrinsic Procedures - -8.9 'ADJUSTR' -- Right adjust a string -====================================== - -_Description_: - 'ADJUSTR(STRING)' will right adjust a string by removing trailing - spaces. Spaces are inserted at the start of the string as needed. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ADJUSTR(STRING)' - -_Arguments_: - STR The type shall be 'CHARACTER'. - -_Return value_: - The return value is of type 'CHARACTER' and of the same kind as - STRING where trailing spaces are removed and the same number of - spaces are inserted at the start of STRING. - -_Example_: - program test_adjustr - character(len=20) :: str = 'gfortran' - str = adjustr(str) - print *, str - end program test_adjustr - -_See also_: - *note ADJUSTL::, *note TRIM:: - - -File: gfortran.info, Node: AIMAG, Next: AINT, Prev: ADJUSTR, Up: Intrinsic Procedures - -8.10 'AIMAG' -- Imaginary part of complex number -================================================ - -_Description_: - 'AIMAG(Z)' yields the imaginary part of complex argument 'Z'. The - 'IMAG(Z)' and 'IMAGPART(Z)' intrinsic functions are provided for - compatibility with 'g77', and their use in new code is strongly - discouraged. - -_Standard_: - Fortran 77 and later, has overloads that are GNU extensions - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = AIMAG(Z)' - -_Arguments_: - Z The type of the argument shall be 'COMPLEX'. - -_Return value_: - The return value is of type 'REAL' with the kind type parameter of - the argument. - -_Example_: - program test_aimag - complex(4) z4 - complex(8) z8 - z4 = cmplx(1.e0_4, 0.e0_4) - z8 = cmplx(0.e0_8, 1.e0_8) - print *, aimag(z4), dimag(z8) - end program test_aimag - -_Specific names_: - Name Argument Return type Standard - 'AIMAG(Z)' 'COMPLEX Z' 'REAL' GNU extension - 'DIMAG(Z)' 'COMPLEX(8) 'REAL(8)' GNU extension - Z' - 'IMAG(Z)' 'COMPLEX Z' 'REAL' GNU extension - 'IMAGPART(Z)' 'COMPLEX Z' 'REAL' GNU extension - - -File: gfortran.info, Node: AINT, Next: ALARM, Prev: AIMAG, Up: Intrinsic Procedures - -8.11 'AINT' -- Truncate to a whole number -========================================= - -_Description_: - 'AINT(A [, KIND])' truncates its argument to a whole number. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = AINT(A [, KIND])' - -_Arguments_: - A The type of the argument shall be 'REAL'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'REAL' with the kind type parameter of - the argument if the optional KIND is absent; otherwise, the kind - type parameter will be given by KIND. If the magnitude of X is - less than one, 'AINT(X)' returns zero. If the magnitude is equal - to or greater than one then it returns the largest whole number - that does not exceed its magnitude. The sign is the same as the - sign of X. - -_Example_: - program test_aint - real(4) x4 - real(8) x8 - x4 = 1.234E0_4 - x8 = 4.321_8 - print *, aint(x4), dint(x8) - x8 = aint(x4,8) - end program test_aint - -_Specific names_: - Name Argument Return type Standard - 'AINT(A)' 'REAL(4) A' 'REAL(4)' Fortran 77 and - later - 'DINT(A)' 'REAL(8) A' 'REAL(8)' Fortran 77 and - later - - -File: gfortran.info, Node: ALARM, Next: ALL, Prev: AINT, Up: Intrinsic Procedures - -8.12 'ALARM' -- Execute a routine after a given delay -===================================================== - -_Description_: - 'ALARM(SECONDS, HANDLER [, STATUS])' causes external subroutine - HANDLER to be executed after a delay of SECONDS by using 'alarm(2)' - to set up a signal and 'signal(2)' to catch it. If STATUS is - supplied, it will be returned with the number of seconds remaining - until any previously scheduled alarm was due to be delivered, or - zero if there was no previously scheduled alarm. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL ALARM(SECONDS, HANDLER [, STATUS])' - -_Arguments_: - SECONDS The type of the argument shall be a scalar - 'INTEGER'. It is 'INTENT(IN)'. - HANDLER Signal handler ('INTEGER FUNCTION' or - 'SUBROUTINE') or dummy/global 'INTEGER' scalar. - The scalar values may be either 'SIG_IGN=1' to - ignore the alarm generated or 'SIG_DFL=0' to set - the default action. It is 'INTENT(IN)'. - STATUS (Optional) STATUS shall be a scalar variable of - the default 'INTEGER' kind. It is - 'INTENT(OUT)'. - -_Example_: - program test_alarm - external handler_print - integer i - call alarm (3, handler_print, i) - print *, i - call sleep(10) - end program test_alarm - This will cause the external routine HANDLER_PRINT to be called - after 3 seconds. - - -File: gfortran.info, Node: ALL, Next: ALLOCATED, Prev: ALARM, Up: Intrinsic Procedures - -8.13 'ALL' -- All values in MASK along DIM are true -=================================================== - -_Description_: - 'ALL(MASK [, DIM])' determines if all the values are true in MASK - in the array along dimension DIM. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = ALL(MASK [, DIM])' - -_Arguments_: - MASK The type of the argument shall be 'LOGICAL' and - it shall not be scalar. - DIM (Optional) DIM shall be a scalar integer with a - value that lies between one and the rank of - MASK. - -_Return value_: - 'ALL(MASK)' returns a scalar value of type 'LOGICAL' where the kind - type parameter is the same as the kind type parameter of MASK. If - DIM is present, then 'ALL(MASK, DIM)' returns an array with the - rank of MASK minus 1. The shape is determined from the shape of - MASK where the DIM dimension is elided. - - (A) - 'ALL(MASK)' is true if all elements of MASK are true. It also - is true if MASK has zero size; otherwise, it is false. - (B) - If the rank of MASK is one, then 'ALL(MASK,DIM)' is equivalent - to 'ALL(MASK)'. If the rank is greater than one, then - 'ALL(MASK,DIM)' is determined by applying 'ALL' to the array - sections. - -_Example_: - program test_all - logical l - l = all((/.true., .true., .true./)) - print *, l - call section - contains - subroutine section - integer a(2,3), b(2,3) - a = 1 - b = 1 - b(2,2) = 2 - print *, all(a .eq. b, 1) - print *, all(a .eq. b, 2) - end subroutine section - end program test_all - - -File: gfortran.info, Node: ALLOCATED, Next: AND, Prev: ALL, Up: Intrinsic Procedures - -8.14 'ALLOCATED' -- Status of an allocatable entity -=================================================== - -_Description_: - 'ALLOCATED(ARRAY)' and 'ALLOCATED(SCALAR)' check the allocation - status of ARRAY and SCALAR, respectively. - -_Standard_: - Fortran 95 and later. Note, the 'SCALAR=' keyword and allocatable - scalar entities are available in Fortran 2003 and later. - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = ALLOCATED(ARRAY)' - 'RESULT = ALLOCATED(SCALAR)' - -_Arguments_: - ARRAY The argument shall be an 'ALLOCATABLE' array. - SCALAR The argument shall be an 'ALLOCATABLE' scalar. - -_Return value_: - The return value is a scalar 'LOGICAL' with the default logical - kind type parameter. If the argument is allocated, then the result - is '.TRUE.'; otherwise, it returns '.FALSE.' - -_Example_: - program test_allocated - integer :: i = 4 - real(4), allocatable :: x(:) - if (.not. allocated(x)) allocate(x(i)) - end program test_allocated - - -File: gfortran.info, Node: AND, Next: ANINT, Prev: ALLOCATED, Up: Intrinsic Procedures - -8.15 'AND' -- Bitwise logical AND -================================= - -_Description_: - Bitwise logical 'AND'. - - This intrinsic routine is provided for backwards compatibility with - GNU Fortran 77. For integer arguments, programmers should consider - the use of the *note IAND:: intrinsic defined by the Fortran - standard. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = AND(I, J)' - -_Arguments_: - I The type shall be either a scalar 'INTEGER' type - or a scalar 'LOGICAL' type. - J The type shall be the same as the type of I. - -_Return value_: - The return type is either a scalar 'INTEGER' or a scalar 'LOGICAL'. - If the kind type parameters differ, then the smaller kind type is - implicitly converted to larger kind, and the return has the larger - kind. - -_Example_: - PROGRAM test_and - LOGICAL :: T = .TRUE., F = .FALSE. - INTEGER :: a, b - DATA a / Z'F' /, b / Z'3' / - - WRITE (*,*) AND(T, T), AND(T, F), AND(F, T), AND(F, F) - WRITE (*,*) AND(a, b) - END PROGRAM - -_See also_: - Fortran 95 elemental function: *note IAND:: - - -File: gfortran.info, Node: ANINT, Next: ANY, Prev: AND, Up: Intrinsic Procedures - -8.16 'ANINT' -- Nearest whole number -==================================== - -_Description_: - 'ANINT(A [, KIND])' rounds its argument to the nearest whole - number. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ANINT(A [, KIND])' - -_Arguments_: - A The type of the argument shall be 'REAL'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type real with the kind type parameter of - the argument if the optional KIND is absent; otherwise, the kind - type parameter will be given by KIND. If A is greater than zero, - 'ANINT(A)' returns 'AINT(X+0.5)'. If A is less than or equal to - zero then it returns 'AINT(X-0.5)'. - -_Example_: - program test_anint - real(4) x4 - real(8) x8 - x4 = 1.234E0_4 - x8 = 4.321_8 - print *, anint(x4), dnint(x8) - x8 = anint(x4,8) - end program test_anint - -_Specific names_: - Name Argument Return type Standard - 'AINT(A)' 'REAL(4) A' 'REAL(4)' Fortran 77 and - later - 'DNINT(A)' 'REAL(8) A' 'REAL(8)' Fortran 77 and - later - - -File: gfortran.info, Node: ANY, Next: ASIN, Prev: ANINT, Up: Intrinsic Procedures - -8.17 'ANY' -- Any value in MASK along DIM is true -================================================= - -_Description_: - 'ANY(MASK [, DIM])' determines if any of the values in the logical - array MASK along dimension DIM are '.TRUE.'. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = ANY(MASK [, DIM])' - -_Arguments_: - MASK The type of the argument shall be 'LOGICAL' and - it shall not be scalar. - DIM (Optional) DIM shall be a scalar integer with a - value that lies between one and the rank of - MASK. - -_Return value_: - 'ANY(MASK)' returns a scalar value of type 'LOGICAL' where the kind - type parameter is the same as the kind type parameter of MASK. If - DIM is present, then 'ANY(MASK, DIM)' returns an array with the - rank of MASK minus 1. The shape is determined from the shape of - MASK where the DIM dimension is elided. - - (A) - 'ANY(MASK)' is true if any element of MASK is true; otherwise, - it is false. It also is false if MASK has zero size. - (B) - If the rank of MASK is one, then 'ANY(MASK,DIM)' is equivalent - to 'ANY(MASK)'. If the rank is greater than one, then - 'ANY(MASK,DIM)' is determined by applying 'ANY' to the array - sections. - -_Example_: - program test_any - logical l - l = any((/.true., .true., .true./)) - print *, l - call section - contains - subroutine section - integer a(2,3), b(2,3) - a = 1 - b = 1 - b(2,2) = 2 - print *, any(a .eq. b, 1) - print *, any(a .eq. b, 2) - end subroutine section - end program test_any - - -File: gfortran.info, Node: ASIN, Next: ASINH, Prev: ANY, Up: Intrinsic Procedures - -8.18 'ASIN' -- Arcsine function -=============================== - -_Description_: - 'ASIN(X)' computes the arcsine of its X (inverse of 'SIN(X)'). - -_Standard_: - Fortran 77 and later, for a complex argument Fortran 2008 or later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ASIN(X)' - -_Arguments_: - X The type shall be either 'REAL' and a magnitude - that is less than or equal to one - or be - 'COMPLEX'. - -_Return value_: - The return value is of the same type and kind as X. The real part - of the result is in radians and lies in the range -\pi/2 \leq \Re - \asin(x) \leq \pi/2. - -_Example_: - program test_asin - real(8) :: x = 0.866_8 - x = asin(x) - end program test_asin - -_Specific names_: - Name Argument Return type Standard - 'ASIN(X)' 'REAL(4) X' 'REAL(4)' Fortran 77 and - later - 'DASIN(X)' 'REAL(8) X' 'REAL(8)' Fortran 77 and - later - -_See also_: - Inverse function: *note SIN:: - - -File: gfortran.info, Node: ASINH, Next: ASSOCIATED, Prev: ASIN, Up: Intrinsic Procedures - -8.19 'ASINH' -- Inverse hyperbolic sine function -================================================ - -_Description_: - 'ASINH(X)' computes the inverse hyperbolic sine of X. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ASINH(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value is of the same type and kind as X. If X is - complex, the imaginary part of the result is in radians and lies - between -\pi/2 \leq \Im \asinh(x) \leq \pi/2. - -_Example_: - PROGRAM test_asinh - REAL(8), DIMENSION(3) :: x = (/ -1.0, 0.0, 1.0 /) - WRITE (*,*) ASINH(x) - END PROGRAM - -_Specific names_: - Name Argument Return type Standard - 'DASINH(X)' 'REAL(8) X' 'REAL(8)' GNU extension. - -_See also_: - Inverse function: *note SINH:: - - -File: gfortran.info, Node: ASSOCIATED, Next: ATAN, Prev: ASINH, Up: Intrinsic Procedures - -8.20 'ASSOCIATED' -- Status of a pointer or pointer/target pair -=============================================================== - -_Description_: - 'ASSOCIATED(POINTER [, TARGET])' determines the status of the - pointer POINTER or if POINTER is associated with the target TARGET. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = ASSOCIATED(POINTER [, TARGET])' - -_Arguments_: - POINTER POINTER shall have the 'POINTER' attribute and - it can be of any type. - TARGET (Optional) TARGET shall be a pointer or a - target. It must have the same type, kind type - parameter, and array rank as POINTER. - The association status of neither POINTER nor TARGET shall be - undefined. - -_Return value_: - 'ASSOCIATED(POINTER)' returns a scalar value of type 'LOGICAL(4)'. - There are several cases: - (A) When the optional TARGET is not present then - 'ASSOCIATED(POINTER)' is true if POINTER is associated with a - target; otherwise, it returns false. - (B) If TARGET is present and a scalar target, the result is true if - TARGET is not a zero-sized storage sequence and the target - associated with POINTER occupies the same storage units. If - POINTER is disassociated, the result is false. - (C) If TARGET is present and an array target, the result is true if - TARGET and POINTER have the same shape, are not zero-sized - arrays, are arrays whose elements are not zero-sized storage - sequences, and TARGET and POINTER occupy the same storage - units in array element order. As in case(B), the result is - false, if POINTER is disassociated. - (D) If TARGET is present and an scalar pointer, the result is true - if TARGET is associated with POINTER, the target associated - with TARGET are not zero-sized storage sequences and occupy - the same storage units. The result is false, if either TARGET - or POINTER is disassociated. - (E) If TARGET is present and an array pointer, the result is true if - target associated with POINTER and the target associated with - TARGET have the same shape, are not zero-sized arrays, are - arrays whose elements are not zero-sized storage sequences, - and TARGET and POINTER occupy the same storage units in array - element order. The result is false, if either TARGET or - POINTER is disassociated. - -_Example_: - program test_associated - implicit none - real, target :: tgt(2) = (/1., 2./) - real, pointer :: ptr(:) - ptr => tgt - if (associated(ptr) .eqv. .false.) call abort - if (associated(ptr,tgt) .eqv. .false.) call abort - end program test_associated - -_See also_: - *note NULL:: - - -File: gfortran.info, Node: ATAN, Next: ATAN2, Prev: ASSOCIATED, Up: Intrinsic Procedures - -8.21 'ATAN' -- Arctangent function -================================== - -_Description_: - 'ATAN(X)' computes the arctangent of X. - -_Standard_: - Fortran 77 and later, for a complex argument and for two arguments - Fortran 2008 or later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ATAN(X)' - 'RESULT = ATAN(Y, X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'; if Y is - present, X shall be REAL. - Y shall - be of the - same type - and kind - as X. - -_Return value_: - The return value is of the same type and kind as X. If Y is - present, the result is identical to 'ATAN2(Y,X)'. Otherwise, it - the arcus tangent of X, where the real part of the result is in - radians and lies in the range -\pi/2 \leq \Re \atan(x) \leq \pi/2. - -_Example_: - program test_atan - real(8) :: x = 2.866_8 - x = atan(x) - end program test_atan - -_Specific names_: - Name Argument Return type Standard - 'ATAN(X)' 'REAL(4) X' 'REAL(4)' Fortran 77 and - later - 'DATAN(X)' 'REAL(8) X' 'REAL(8)' Fortran 77 and - later - -_See also_: - Inverse function: *note TAN:: - - -File: gfortran.info, Node: ATAN2, Next: ATANH, Prev: ATAN, Up: Intrinsic Procedures - -8.22 'ATAN2' -- Arctangent function -=================================== - -_Description_: - 'ATAN2(Y, X)' computes the principal value of the argument function - of the complex number X + i Y. This function can be used to - transform from Cartesian into polar coordinates and allows to - determine the angle in the correct quadrant. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ATAN2(Y, X)' - -_Arguments_: - Y The type shall be 'REAL'. - X The type and kind type parameter shall be the - same as Y. If Y is zero, then X must be - nonzero. - -_Return value_: - The return value has the same type and kind type parameter as Y. - It is the principal value of the complex number X + i Y. If X is - nonzero, then it lies in the range -\pi \le \atan (x) \leq \pi. - The sign is positive if Y is positive. If Y is zero, then the - return value is zero if X is strictly positive, \pi if X is - negative and Y is positive zero (or the processor does not handle - signed zeros), and -\pi if X is negative and Y is negative zero. - Finally, if X is zero, then the magnitude of the result is \pi/2. - -_Example_: - program test_atan2 - real(4) :: x = 1.e0_4, y = 0.5e0_4 - x = atan2(y,x) - end program test_atan2 - -_Specific names_: - Name Argument Return type Standard - 'ATAN2(X, 'REAL(4) X, 'REAL(4)' Fortran 77 and - Y)' Y' later - 'DATAN2(X, 'REAL(8) X, 'REAL(8)' Fortran 77 and - Y)' Y' later - - -File: gfortran.info, Node: ATANH, Next: ATOMIC_DEFINE, Prev: ATAN2, Up: Intrinsic Procedures - -8.23 'ATANH' -- Inverse hyperbolic tangent function -=================================================== - -_Description_: - 'ATANH(X)' computes the inverse hyperbolic tangent of X. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ATANH(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value has same type and kind as X. If X is complex, the - imaginary part of the result is in radians and lies between -\pi/2 - \leq \Im \atanh(x) \leq \pi/2. - -_Example_: - PROGRAM test_atanh - REAL, DIMENSION(3) :: x = (/ -1.0, 0.0, 1.0 /) - WRITE (*,*) ATANH(x) - END PROGRAM - -_Specific names_: - Name Argument Return type Standard - 'DATANH(X)' 'REAL(8) X' 'REAL(8)' GNU extension - -_See also_: - Inverse function: *note TANH:: - - -File: gfortran.info, Node: ATOMIC_DEFINE, Next: ATOMIC_REF, Prev: ATANH, Up: Intrinsic Procedures - -8.24 'ATOMIC_DEFINE' -- Setting a variable atomically -===================================================== - -_Description_: - 'ATOMIC_DEFINE(ATOM, VALUE)' defines the variable ATOM with the - value VALUE atomically. - -_Standard_: - Fortran 2008 and later - -_Class_: - Atomic subroutine - -_Syntax_: - 'CALL ATOMIC_DEFINE(ATOM, VALUE)' - -_Arguments_: - ATOM Scalar coarray or coindexed variable of either - integer type with 'ATOMIC_INT_KIND' kind or - logical type with 'ATOMIC_LOGICAL_KIND' kind. - VALURE Scalar and of the same type as ATOM. If the - kind is different, the value is converted to the - kind of ATOM. - -_Example_: - program atomic - use iso_fortran_env - integer(atomic_int_kind) :: atom[*] - call atomic_define (atom[1], this_image()) - end program atomic - -_See also_: - *note ATOMIC_REF::, *note ISO_FORTRAN_ENV:: - - -File: gfortran.info, Node: ATOMIC_REF, Next: BACKTRACE, Prev: ATOMIC_DEFINE, Up: Intrinsic Procedures - -8.25 'ATOMIC_REF' -- Obtaining the value of a variable atomically -================================================================= - -_Description_: - 'ATOMIC_DEFINE(ATOM, VALUE)' atomically assigns the value of the - variable ATOM to VALUE. - -_Standard_: - Fortran 2008 and later - -_Class_: - Atomic subroutine - -_Syntax_: - 'CALL ATOMIC_REF(VALUE, ATOM)' - -_Arguments_: - VALURE Scalar and of the same type as ATOM. If the - kind is different, the value is converted to the - kind of ATOM. - ATOM Scalar coarray or coindexed variable of either - integer type with 'ATOMIC_INT_KIND' kind or - logical type with 'ATOMIC_LOGICAL_KIND' kind. - -_Example_: - program atomic - use iso_fortran_env - logical(atomic_logical_kind) :: atom[*] - logical :: val - call atomic_ref (atom, .false.) - ! ... - call atomic_ref (atom, val) - if (val) then - print *, "Obtained" - end if - end program atomic - -_See also_: - *note ATOMIC_DEFINE::, *note ISO_FORTRAN_ENV:: - - -File: gfortran.info, Node: BACKTRACE, Next: BESSEL_J0, Prev: ATOMIC_REF, Up: Intrinsic Procedures - -8.26 'BACKTRACE' -- Show a backtrace -==================================== - -_Description_: - 'BACKTRACE' shows a backtrace at an arbitrary place in user code. - Program execution continues normally afterwards. The backtrace - information is printed to the unit corresponding to 'ERROR_UNIT' in - 'ISO_FORTRAN_ENV'. - -_Standard_: - GNU Extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL BACKTRACE' - -_Arguments_: - None - -_See also_: - *note ABORT:: - - -File: gfortran.info, Node: BESSEL_J0, Next: BESSEL_J1, Prev: BACKTRACE, Up: Intrinsic Procedures - -8.27 'BESSEL_J0' -- Bessel function of the first kind of order 0 -================================================================ - -_Description_: - 'BESSEL_J0(X)' computes the Bessel function of the first kind of - order 0 of X. This function is available under the name 'BESJ0' as - a GNU extension. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = BESSEL_J0(X)' - -_Arguments_: - X The type shall be 'REAL', and it shall be - scalar. - -_Return value_: - The return value is of type 'REAL' and lies in the range - - 0.4027... \leq Bessel (0,x) \leq 1. It has the same kind as X. - -_Example_: - program test_besj0 - real(8) :: x = 0.0_8 - x = bessel_j0(x) - end program test_besj0 - -_Specific names_: - Name Argument Return type Standard - 'DBESJ0(X)' 'REAL(8) X' 'REAL(8)' GNU extension - - -File: gfortran.info, Node: BESSEL_J1, Next: BESSEL_JN, Prev: BESSEL_J0, Up: Intrinsic Procedures - -8.28 'BESSEL_J1' -- Bessel function of the first kind of order 1 -================================================================ - -_Description_: - 'BESSEL_J1(X)' computes the Bessel function of the first kind of - order 1 of X. This function is available under the name 'BESJ1' as - a GNU extension. - -_Standard_: - Fortran 2008 - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = BESSEL_J1(X)' - -_Arguments_: - X The type shall be 'REAL', and it shall be - scalar. - -_Return value_: - The return value is of type 'REAL' and it lies in the range - - 0.5818... \leq Bessel (0,x) \leq 0.5818 . It has the same kind as - X. - -_Example_: - program test_besj1 - real(8) :: x = 1.0_8 - x = bessel_j1(x) - end program test_besj1 - -_Specific names_: - Name Argument Return type Standard - 'DBESJ1(X)' 'REAL(8) X' 'REAL(8)' GNU extension - - -File: gfortran.info, Node: BESSEL_JN, Next: BESSEL_Y0, Prev: BESSEL_J1, Up: Intrinsic Procedures - -8.29 'BESSEL_JN' -- Bessel function of the first kind -===================================================== - -_Description_: - 'BESSEL_JN(N, X)' computes the Bessel function of the first kind of - order N of X. This function is available under the name 'BESJN' as - a GNU extension. If N and X are arrays, their ranks and shapes - shall conform. - - 'BESSEL_JN(N1, N2, X)' returns an array with the Bessel functions - of the first kind of the orders N1 to N2. - -_Standard_: - Fortran 2008 and later, negative N is allowed as GNU extension - -_Class_: - Elemental function, except for the transformational function - 'BESSEL_JN(N1, N2, X)' - -_Syntax_: - 'RESULT = BESSEL_JN(N, X)' - 'RESULT = BESSEL_JN(N1, N2, X)' - -_Arguments_: - N Shall be a scalar or an array of type 'INTEGER'. - N1 Shall be a non-negative scalar of type - 'INTEGER'. - N2 Shall be a non-negative scalar of type - 'INTEGER'. - X Shall be a scalar or an array of type 'REAL'; - for 'BESSEL_JN(N1, N2, X)' it shall be scalar. - -_Return value_: - The return value is a scalar of type 'REAL'. It has the same kind - as X. - -_Note_: - The transformational function uses a recurrence algorithm which - might, for some values of X, lead to different results than calls - to the elemental function. - -_Example_: - program test_besjn - real(8) :: x = 1.0_8 - x = bessel_jn(5,x) - end program test_besjn - -_Specific names_: - Name Argument Return type Standard - 'DBESJN(N, 'INTEGER N' 'REAL(8)' GNU extension - X)' - 'REAL(8) X' - - -File: gfortran.info, Node: BESSEL_Y0, Next: BESSEL_Y1, Prev: BESSEL_JN, Up: Intrinsic Procedures - -8.30 'BESSEL_Y0' -- Bessel function of the second kind of order 0 -================================================================= - -_Description_: - 'BESSEL_Y0(X)' computes the Bessel function of the second kind of - order 0 of X. This function is available under the name 'BESY0' as - a GNU extension. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = BESSEL_Y0(X)' - -_Arguments_: - X The type shall be 'REAL', and it shall be - scalar. - -_Return value_: - The return value is a scalar of type 'REAL'. It has the same kind - as X. - -_Example_: - program test_besy0 - real(8) :: x = 0.0_8 - x = bessel_y0(x) - end program test_besy0 - -_Specific names_: - Name Argument Return type Standard - 'DBESY0(X)' 'REAL(8) X' 'REAL(8)' GNU extension - - -File: gfortran.info, Node: BESSEL_Y1, Next: BESSEL_YN, Prev: BESSEL_Y0, Up: Intrinsic Procedures - -8.31 'BESSEL_Y1' -- Bessel function of the second kind of order 1 -================================================================= - -_Description_: - 'BESSEL_Y1(X)' computes the Bessel function of the second kind of - order 1 of X. This function is available under the name 'BESY1' as - a GNU extension. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = BESSEL_Y1(X)' - -_Arguments_: - X The type shall be 'REAL', and it shall be - scalar. - -_Return value_: - The return value is a scalar of type 'REAL'. It has the same kind - as X. - -_Example_: - program test_besy1 - real(8) :: x = 1.0_8 - x = bessel_y1(x) - end program test_besy1 - -_Specific names_: - Name Argument Return type Standard - 'DBESY1(X)' 'REAL(8) X' 'REAL(8)' GNU extension - - -File: gfortran.info, Node: BESSEL_YN, Next: BGE, Prev: BESSEL_Y1, Up: Intrinsic Procedures - -8.32 'BESSEL_YN' -- Bessel function of the second kind -====================================================== - -_Description_: - 'BESSEL_YN(N, X)' computes the Bessel function of the second kind - of order N of X. This function is available under the name 'BESYN' - as a GNU extension. If N and X are arrays, their ranks and shapes - shall conform. - - 'BESSEL_YN(N1, N2, X)' returns an array with the Bessel functions - of the first kind of the orders N1 to N2. - -_Standard_: - Fortran 2008 and later, negative N is allowed as GNU extension - -_Class_: - Elemental function, except for the transformational function - 'BESSEL_YN(N1, N2, X)' - -_Syntax_: - 'RESULT = BESSEL_YN(N, X)' - 'RESULT = BESSEL_YN(N1, N2, X)' - -_Arguments_: - N Shall be a scalar or an array of type 'INTEGER' - . - N1 Shall be a non-negative scalar of type - 'INTEGER'. - N2 Shall be a non-negative scalar of type - 'INTEGER'. - X Shall be a scalar or an array of type 'REAL'; - for 'BESSEL_YN(N1, N2, X)' it shall be scalar. - -_Return value_: - The return value is a scalar of type 'REAL'. It has the same kind - as X. - -_Note_: - The transformational function uses a recurrence algorithm which - might, for some values of X, lead to different results than calls - to the elemental function. - -_Example_: - program test_besyn - real(8) :: x = 1.0_8 - x = bessel_yn(5,x) - end program test_besyn - -_Specific names_: - Name Argument Return type Standard - 'DBESYN(N,X)' 'INTEGER N' 'REAL(8)' GNU extension - 'REAL(8) X' - - -File: gfortran.info, Node: BGE, Next: BGT, Prev: BESSEL_YN, Up: Intrinsic Procedures - -8.33 'BGE' -- Bitwise greater than or equal to -============================================== - -_Description_: - Determines whether an integral is a bitwise greater than or equal - to another. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = BGE(I, J)' - -_Arguments_: - I Shall be of 'INTEGER' type. - J Shall be of 'INTEGER' type, and of the same kind - as I. - -_Return value_: - The return value is of type 'LOGICAL' and of the default kind. - -_See also_: - *note BGT::, *note BLE::, *note BLT:: - - -File: gfortran.info, Node: BGT, Next: BIT_SIZE, Prev: BGE, Up: Intrinsic Procedures - -8.34 'BGT' -- Bitwise greater than -================================== - -_Description_: - Determines whether an integral is a bitwise greater than another. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = BGT(I, J)' - -_Arguments_: - I Shall be of 'INTEGER' type. - J Shall be of 'INTEGER' type, and of the same kind - as I. - -_Return value_: - The return value is of type 'LOGICAL' and of the default kind. - -_See also_: - *note BGE::, *note BLE::, *note BLT:: - - -File: gfortran.info, Node: BIT_SIZE, Next: BLE, Prev: BGT, Up: Intrinsic Procedures - -8.35 'BIT_SIZE' -- Bit size inquiry function -============================================ - -_Description_: - 'BIT_SIZE(I)' returns the number of bits (integer precision plus - sign bit) represented by the type of I. The result of - 'BIT_SIZE(I)' is independent of the actual value of I. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = BIT_SIZE(I)' - -_Arguments_: - I The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' - -_Example_: - program test_bit_size - integer :: i = 123 - integer :: size - size = bit_size(i) - print *, size - end program test_bit_size - - -File: gfortran.info, Node: BLE, Next: BLT, Prev: BIT_SIZE, Up: Intrinsic Procedures - -8.36 'BLE' -- Bitwise less than or equal to -=========================================== - -_Description_: - Determines whether an integral is a bitwise less than or equal to - another. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = BLE(I, J)' - -_Arguments_: - I Shall be of 'INTEGER' type. - J Shall be of 'INTEGER' type, and of the same kind - as I. - -_Return value_: - The return value is of type 'LOGICAL' and of the default kind. - -_See also_: - *note BGT::, *note BGE::, *note BLT:: - - -File: gfortran.info, Node: BLT, Next: BTEST, Prev: BLE, Up: Intrinsic Procedures - -8.37 'BLT' -- Bitwise less than -=============================== - -_Description_: - Determines whether an integral is a bitwise less than another. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = BLT(I, J)' - -_Arguments_: - I Shall be of 'INTEGER' type. - J Shall be of 'INTEGER' type, and of the same kind - as I. - -_Return value_: - The return value is of type 'LOGICAL' and of the default kind. - -_See also_: - *note BGE::, *note BGT::, *note BLE:: - - -File: gfortran.info, Node: BTEST, Next: C_ASSOCIATED, Prev: BLT, Up: Intrinsic Procedures - -8.38 'BTEST' -- Bit test function -================================= - -_Description_: - 'BTEST(I,POS)' returns logical '.TRUE.' if the bit at POS in I is - set. The counting of the bits starts at 0. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = BTEST(I, POS)' - -_Arguments_: - I The type shall be 'INTEGER'. - POS The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'LOGICAL' - -_Example_: - program test_btest - integer :: i = 32768 + 1024 + 64 - integer :: pos - logical :: bool - do pos=0,16 - bool = btest(i, pos) - print *, pos, bool - end do - end program test_btest - - -File: gfortran.info, Node: C_ASSOCIATED, Next: C_F_POINTER, Prev: BTEST, Up: Intrinsic Procedures - -8.39 'C_ASSOCIATED' -- Status of a C pointer -============================================ - -_Description_: - 'C_ASSOCIATED(c_prt_1[, c_ptr_2])' determines the status of the C - pointer C_PTR_1 or if C_PTR_1 is associated with the target - C_PTR_2. - -_Standard_: - Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = C_ASSOCIATED(c_prt_1[, c_ptr_2])' - -_Arguments_: - C_PTR_1 Scalar of the type 'C_PTR' or 'C_FUNPTR'. - C_PTR_2 (Optional) Scalar of the same type as C_PTR_1. - -_Return value_: - The return value is of type 'LOGICAL'; it is '.false.' if either - C_PTR_1 is a C NULL pointer or if C_PTR1 and C_PTR_2 point to - different addresses. - -_Example_: - subroutine association_test(a,b) - use iso_c_binding, only: c_associated, c_loc, c_ptr - implicit none - real, pointer :: a - type(c_ptr) :: b - if(c_associated(b, c_loc(a))) & - stop 'b and a do not point to same target' - end subroutine association_test - -_See also_: - *note C_LOC::, *note C_FUNLOC:: - - -File: gfortran.info, Node: C_F_POINTER, Next: C_F_PROCPOINTER, Prev: C_ASSOCIATED, Up: Intrinsic Procedures - -8.40 'C_F_POINTER' -- Convert C into Fortran pointer -==================================================== - -_Description_: - 'C_F_POINTER(CPTR, FPTR[, SHAPE])' assigns the target of the C - pointer CPTR to the Fortran pointer FPTR and specifies its shape. - -_Standard_: - Fortran 2003 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL C_F_POINTER(CPTR, FPTR[, SHAPE])' - -_Arguments_: - CPTR scalar of the type 'C_PTR'. It is 'INTENT(IN)'. - FPTR pointer interoperable with CPTR. It is - 'INTENT(OUT)'. - SHAPE (Optional) Rank-one array of type 'INTEGER' with - 'INTENT(IN)'. It shall be present if and only - if FPTR is an array. The size must be equal to - the rank of FPTR. - -_Example_: - program main - use iso_c_binding - implicit none - interface - subroutine my_routine(p) bind(c,name='myC_func') - import :: c_ptr - type(c_ptr), intent(out) :: p - end subroutine - end interface - type(c_ptr) :: cptr - real,pointer :: a(:) - call my_routine(cptr) - call c_f_pointer(cptr, a, [12]) - end program main - -_See also_: - *note C_LOC::, *note C_F_PROCPOINTER:: - - -File: gfortran.info, Node: C_F_PROCPOINTER, Next: C_FUNLOC, Prev: C_F_POINTER, Up: Intrinsic Procedures - -8.41 'C_F_PROCPOINTER' -- Convert C into Fortran procedure pointer -================================================================== - -_Description_: - 'C_F_PROCPOINTER(CPTR, FPTR)' Assign the target of the C function - pointer CPTR to the Fortran procedure pointer FPTR. - -_Standard_: - Fortran 2003 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL C_F_PROCPOINTER(cptr, fptr)' - -_Arguments_: - CPTR scalar of the type 'C_FUNPTR'. It is - 'INTENT(IN)'. - FPTR procedure pointer interoperable with CPTR. It - is 'INTENT(OUT)'. - -_Example_: - program main - use iso_c_binding - implicit none - abstract interface - function func(a) - import :: c_float - real(c_float), intent(in) :: a - real(c_float) :: func - end function - end interface - interface - function getIterFunc() bind(c,name="getIterFunc") - import :: c_funptr - type(c_funptr) :: getIterFunc - end function - end interface - type(c_funptr) :: cfunptr - procedure(func), pointer :: myFunc - cfunptr = getIterFunc() - call c_f_procpointer(cfunptr, myFunc) - end program main - -_See also_: - *note C_LOC::, *note C_F_POINTER:: - - -File: gfortran.info, Node: C_FUNLOC, Next: C_LOC, Prev: C_F_PROCPOINTER, Up: Intrinsic Procedures - -8.42 'C_FUNLOC' -- Obtain the C address of a procedure -====================================================== - -_Description_: - 'C_FUNLOC(x)' determines the C address of the argument. - -_Standard_: - Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = C_FUNLOC(x)' - -_Arguments_: - X Interoperable function or pointer to such - function. - -_Return value_: - The return value is of type 'C_FUNPTR' and contains the C address - of the argument. - -_Example_: - module x - use iso_c_binding - implicit none - contains - subroutine sub(a) bind(c) - real(c_float) :: a - a = sqrt(a)+5.0 - end subroutine sub - end module x - program main - use iso_c_binding - use x - implicit none - interface - subroutine my_routine(p) bind(c,name='myC_func') - import :: c_funptr - type(c_funptr), intent(in) :: p - end subroutine - end interface - call my_routine(c_funloc(sub)) - end program main - -_See also_: - *note C_ASSOCIATED::, *note C_LOC::, *note C_F_POINTER::, *note - C_F_PROCPOINTER:: - - -File: gfortran.info, Node: C_LOC, Next: C_SIZEOF, Prev: C_FUNLOC, Up: Intrinsic Procedures - -8.43 'C_LOC' -- Obtain the C address of an object -================================================= - -_Description_: - 'C_LOC(X)' determines the C address of the argument. - -_Standard_: - Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = C_LOC(X)' - -_Arguments_: - X Shall have either the POINTER or TARGET attribute. - It shall not be a coindexed object. It shall either - be a variable with interoperable type and kind type - parameters, or be a scalar, nonpolymorphic variable - with no length type parameters. - - -_Return value_: - The return value is of type 'C_PTR' and contains the C address of - the argument. - -_Example_: - subroutine association_test(a,b) - use iso_c_binding, only: c_associated, c_loc, c_ptr - implicit none - real, pointer :: a - type(c_ptr) :: b - if(c_associated(b, c_loc(a))) & - stop 'b and a do not point to same target' - end subroutine association_test - -_See also_: - *note C_ASSOCIATED::, *note C_FUNLOC::, *note C_F_POINTER::, *note - C_F_PROCPOINTER:: - - -File: gfortran.info, Node: C_SIZEOF, Next: CEILING, Prev: C_LOC, Up: Intrinsic Procedures - -8.44 'C_SIZEOF' -- Size in bytes of an expression -================================================= - -_Description_: - 'C_SIZEOF(X)' calculates the number of bytes of storage the - expression 'X' occupies. - -_Standard_: - Fortran 2008 - -_Class_: - Inquiry function of the module 'ISO_C_BINDING' - -_Syntax_: - 'N = C_SIZEOF(X)' - -_Arguments_: - X The argument shall be an interoperable data - entity. - -_Return value_: - The return value is of type integer and of the system-dependent - kind 'C_SIZE_T' (from the 'ISO_C_BINDING' module). Its value is - the number of bytes occupied by the argument. If the argument has - the 'POINTER' attribute, the number of bytes of the storage area - pointed to is returned. If the argument is of a derived type with - 'POINTER' or 'ALLOCATABLE' components, the return value does not - account for the sizes of the data pointed to by these components. - -_Example_: - use iso_c_binding - integer(c_int) :: i - real(c_float) :: r, s(5) - print *, (c_sizeof(s)/c_sizeof(r) == 5) - end - The example will print '.TRUE.' unless you are using a platform - where default 'REAL' variables are unusually padded. - -_See also_: - *note SIZEOF::, *note STORAGE_SIZE:: - - -File: gfortran.info, Node: CEILING, Next: CHAR, Prev: C_SIZEOF, Up: Intrinsic Procedures - -8.45 'CEILING' -- Integer ceiling function -========================================== - -_Description_: - 'CEILING(A)' returns the least integer greater than or equal to A. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = CEILING(A [, KIND])' - -_Arguments_: - A The type shall be 'REAL'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER(KIND)' if KIND is present and - a default-kind 'INTEGER' otherwise. - -_Example_: - program test_ceiling - real :: x = 63.29 - real :: y = -63.59 - print *, ceiling(x) ! returns 64 - print *, ceiling(y) ! returns -63 - end program test_ceiling - -_See also_: - *note FLOOR::, *note NINT:: - - -File: gfortran.info, Node: CHAR, Next: CHDIR, Prev: CEILING, Up: Intrinsic Procedures - -8.46 'CHAR' -- Character conversion function -============================================ - -_Description_: - 'CHAR(I [, KIND])' returns the character represented by the integer - I. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = CHAR(I [, KIND])' - -_Arguments_: - I The type shall be 'INTEGER'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'CHARACTER(1)' - -_Example_: - program test_char - integer :: i = 74 - character(1) :: c - c = char(i) - print *, i, c ! returns 'J' - end program test_char - -_Specific names_: - Name Argument Return type Standard - 'CHAR(I)' 'INTEGER I' 'CHARACTER(LEN=1)'F77 and later - -_Note_: - See *note ICHAR:: for a discussion of converting between numerical - values and formatted string representations. - -_See also_: - *note ACHAR::, *note IACHAR::, *note ICHAR:: - - -File: gfortran.info, Node: CHDIR, Next: CHMOD, Prev: CHAR, Up: Intrinsic Procedures - -8.47 'CHDIR' -- Change working directory -======================================== - -_Description_: - Change current working directory to a specified path. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL CHDIR(NAME [, STATUS])' - 'STATUS = CHDIR(NAME)' - -_Arguments_: - NAME The type shall be 'CHARACTER' of default kind - and shall specify a valid path within the file - system. - STATUS (Optional) 'INTEGER' status flag of the default - kind. Returns 0 on success, and a system - specific and nonzero error code otherwise. - -_Example_: - PROGRAM test_chdir - CHARACTER(len=255) :: path - CALL getcwd(path) - WRITE(*,*) TRIM(path) - CALL chdir("/tmp") - CALL getcwd(path) - WRITE(*,*) TRIM(path) - END PROGRAM - -_See also_: - *note GETCWD:: - - -File: gfortran.info, Node: CHMOD, Next: CMPLX, Prev: CHDIR, Up: Intrinsic Procedures - -8.48 'CHMOD' -- Change access permissions of files -================================================== - -_Description_: - 'CHMOD' changes the permissions of a file. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL CHMOD(NAME, MODE[, STATUS])' - 'STATUS = CHMOD(NAME, MODE)' - -_Arguments_: - - NAME Scalar 'CHARACTER' of default kind with the file - name. Trailing blanks are ignored unless the - character 'achar(0)' is present, then all - characters up to and excluding 'achar(0)' are - used as the file name. - - MODE Scalar 'CHARACTER' of default kind giving the - file permission. MODE uses the same syntax as - the 'chmod' utility as defined by the POSIX - standard. The argument shall either be a string - of a nonnegative octal number or a symbolic - mode. - - STATUS (optional) scalar 'INTEGER', which is '0' on - success and nonzero otherwise. - -_Return value_: - In either syntax, STATUS is set to '0' on success and nonzero - otherwise. - -_Example_: - 'CHMOD' as subroutine - program chmod_test - implicit none - integer :: status - call chmod('test.dat','u+x',status) - print *, 'Status: ', status - end program chmod_test - 'CHMOD' as function: - program chmod_test - implicit none - integer :: status - status = chmod('test.dat','u+x') - print *, 'Status: ', status - end program chmod_test - - -File: gfortran.info, Node: CMPLX, Next: COMMAND_ARGUMENT_COUNT, Prev: CHMOD, Up: Intrinsic Procedures - -8.49 'CMPLX' -- Complex conversion function -=========================================== - -_Description_: - 'CMPLX(X [, Y [, KIND]])' returns a complex number where X is - converted to the real component. If Y is present it is converted - to the imaginary component. If Y is not present then the imaginary - component is set to 0.0. If X is complex then Y must not be - present. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = CMPLX(X [, Y [, KIND]])' - -_Arguments_: - X The type may be 'INTEGER', 'REAL', or 'COMPLEX'. - Y (Optional; only allowed if X is not 'COMPLEX'.) - May be 'INTEGER' or 'REAL'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of 'COMPLEX' type, with a kind equal to KIND if - it is specified. If KIND is not specified, the result is of the - default 'COMPLEX' kind, regardless of the kinds of X and Y. - -_Example_: - program test_cmplx - integer :: i = 42 - real :: x = 3.14 - complex :: z - z = cmplx(i, x) - print *, z, cmplx(x) - end program test_cmplx - -_See also_: - *note COMPLEX:: - - -File: gfortran.info, Node: COMMAND_ARGUMENT_COUNT, Next: COMPILER_OPTIONS, Prev: CMPLX, Up: Intrinsic Procedures - -8.50 'COMMAND_ARGUMENT_COUNT' -- Get number of command line arguments -===================================================================== - -_Description_: - 'COMMAND_ARGUMENT_COUNT' returns the number of arguments passed on - the command line when the containing program was invoked. - -_Standard_: - Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = COMMAND_ARGUMENT_COUNT()' - -_Arguments_: - None - -_Return value_: - The return value is an 'INTEGER' of default kind. - -_Example_: - program test_command_argument_count - integer :: count - count = command_argument_count() - print *, count - end program test_command_argument_count - -_See also_: - *note GET_COMMAND::, *note GET_COMMAND_ARGUMENT:: - - -File: gfortran.info, Node: COMPILER_OPTIONS, Next: COMPILER_VERSION, Prev: COMMAND_ARGUMENT_COUNT, Up: Intrinsic Procedures - -8.51 'COMPILER_OPTIONS' -- Options passed to the compiler -========================================================= - -_Description_: - 'COMPILER_OPTIONS' returns a string with the options used for - compiling. - -_Standard_: - Fortran 2008 - -_Class_: - Inquiry function of the module 'ISO_FORTRAN_ENV' - -_Syntax_: - 'STR = COMPILER_OPTIONS()' - -_Arguments_: - None. - -_Return value_: - The return value is a default-kind string with system-dependent - length. It contains the compiler flags used to compile the file, - which called the 'COMPILER_OPTIONS' intrinsic. - -_Example_: - use iso_fortran_env - print '(4a)', 'This file was compiled by ', & - compiler_version(), ' using the options ', & - compiler_options() - end - -_See also_: - *note COMPILER_VERSION::, *note ISO_FORTRAN_ENV:: - - -File: gfortran.info, Node: COMPILER_VERSION, Next: COMPLEX, Prev: COMPILER_OPTIONS, Up: Intrinsic Procedures - -8.52 'COMPILER_VERSION' -- Compiler version string -================================================== - -_Description_: - 'COMPILER_VERSION' returns a string with the name and the version - of the compiler. - -_Standard_: - Fortran 2008 - -_Class_: - Inquiry function of the module 'ISO_FORTRAN_ENV' - -_Syntax_: - 'STR = COMPILER_VERSION()' - -_Arguments_: - None. - -_Return value_: - The return value is a default-kind string with system-dependent - length. It contains the name of the compiler and its version - number. - -_Example_: - use iso_fortran_env - print '(4a)', 'This file was compiled by ', & - compiler_version(), ' using the options ', & - compiler_options() - end - -_See also_: - *note COMPILER_OPTIONS::, *note ISO_FORTRAN_ENV:: - - -File: gfortran.info, Node: COMPLEX, Next: CONJG, Prev: COMPILER_VERSION, Up: Intrinsic Procedures - -8.53 'COMPLEX' -- Complex conversion function -============================================= - -_Description_: - 'COMPLEX(X, Y)' returns a complex number where X is converted to - the real component and Y is converted to the imaginary component. - -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = COMPLEX(X, Y)' - -_Arguments_: - X The type may be 'INTEGER' or 'REAL'. - Y The type may be 'INTEGER' or 'REAL'. - -_Return value_: - If X and Y are both of 'INTEGER' type, then the return value is of - default 'COMPLEX' type. - - If X and Y are of 'REAL' type, or one is of 'REAL' type and one is - of 'INTEGER' type, then the return value is of 'COMPLEX' type with - a kind equal to that of the 'REAL' argument with the highest - precision. - -_Example_: - program test_complex - integer :: i = 42 - real :: x = 3.14 - print *, complex(i, x) - end program test_complex - -_See also_: - *note CMPLX:: - - -File: gfortran.info, Node: CONJG, Next: COS, Prev: COMPLEX, Up: Intrinsic Procedures - -8.54 'CONJG' -- Complex conjugate function -========================================== - -_Description_: - 'CONJG(Z)' returns the conjugate of Z. If Z is '(x, y)' then the - result is '(x, -y)' - -_Standard_: - Fortran 77 and later, has overloads that are GNU extensions - -_Class_: - Elemental function - -_Syntax_: - 'Z = CONJG(Z)' - -_Arguments_: - Z The type shall be 'COMPLEX'. - -_Return value_: - The return value is of type 'COMPLEX'. - -_Example_: - program test_conjg - complex :: z = (2.0, 3.0) - complex(8) :: dz = (2.71_8, -3.14_8) - z= conjg(z) - print *, z - dz = dconjg(dz) - print *, dz - end program test_conjg - -_Specific names_: - Name Argument Return type Standard - 'CONJG(Z)' 'COMPLEX Z' 'COMPLEX' GNU extension - 'DCONJG(Z)' 'COMPLEX(8) 'COMPLEX(8)' GNU extension - Z' - - -File: gfortran.info, Node: COS, Next: COSH, Prev: CONJG, Up: Intrinsic Procedures - -8.55 'COS' -- Cosine function -============================= - -_Description_: - 'COS(X)' computes the cosine of X. - -_Standard_: - Fortran 77 and later, has overloads that are GNU extensions - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = COS(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value is of the same type and kind as X. The real part - of the result is in radians. If X is of the type 'REAL', the - return value lies in the range -1 \leq \cos (x) \leq 1. - -_Example_: - program test_cos - real :: x = 0.0 - x = cos(x) - end program test_cos - -_Specific names_: - Name Argument Return type Standard - 'COS(X)' 'REAL(4) X' 'REAL(4)' Fortran 77 and - later - 'DCOS(X)' 'REAL(8) X' 'REAL(8)' Fortran 77 and - later - 'CCOS(X)' 'COMPLEX(4) 'COMPLEX(4)' Fortran 77 and - X' later - 'ZCOS(X)' 'COMPLEX(8) 'COMPLEX(8)' GNU extension - X' - 'CDCOS(X)' 'COMPLEX(8) 'COMPLEX(8)' GNU extension - X' - -_See also_: - Inverse function: *note ACOS:: - - -File: gfortran.info, Node: COSH, Next: COUNT, Prev: COS, Up: Intrinsic Procedures - -8.56 'COSH' -- Hyperbolic cosine function -========================================= - -_Description_: - 'COSH(X)' computes the hyperbolic cosine of X. - -_Standard_: - Fortran 77 and later, for a complex argument Fortran 2008 or later - -_Class_: - Elemental function - -_Syntax_: - 'X = COSH(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value has same type and kind as X. If X is complex, the - imaginary part of the result is in radians. If X is 'REAL', the - return value has a lower bound of one, \cosh (x) \geq 1. - -_Example_: - program test_cosh - real(8) :: x = 1.0_8 - x = cosh(x) - end program test_cosh - -_Specific names_: - Name Argument Return type Standard - 'COSH(X)' 'REAL(4) X' 'REAL(4)' Fortran 77 and - later - 'DCOSH(X)' 'REAL(8) X' 'REAL(8)' Fortran 77 and - later - -_See also_: - Inverse function: *note ACOSH:: - - -File: gfortran.info, Node: COUNT, Next: CPU_TIME, Prev: COSH, Up: Intrinsic Procedures - -8.57 'COUNT' -- Count function -============================== - -_Description_: - - Counts the number of '.TRUE.' elements in a logical MASK, or, if - the DIM argument is supplied, counts the number of elements along - each row of the array in the DIM direction. If the array has zero - size, or all of the elements of MASK are '.FALSE.', then the result - is '0'. - -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = COUNT(MASK [, DIM, KIND])' - -_Arguments_: - MASK The type shall be 'LOGICAL'. - DIM (Optional) The type shall be 'INTEGER'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. If DIM is - present, the result is an array with a rank one less than the rank - of ARRAY, and a size corresponding to the shape of ARRAY with the - DIM dimension removed. - -_Example_: - program test_count - integer, dimension(2,3) :: a, b - logical, dimension(2,3) :: mask - a = reshape( (/ 1, 2, 3, 4, 5, 6 /), (/ 2, 3 /)) - b = reshape( (/ 0, 7, 3, 4, 5, 8 /), (/ 2, 3 /)) - print '(3i3)', a(1,:) - print '(3i3)', a(2,:) - print * - print '(3i3)', b(1,:) - print '(3i3)', b(2,:) - print * - mask = a.ne.b - print '(3l3)', mask(1,:) - print '(3l3)', mask(2,:) - print * - print '(3i3)', count(mask) - print * - print '(3i3)', count(mask, 1) - print * - print '(3i3)', count(mask, 2) - end program test_count - - -File: gfortran.info, Node: CPU_TIME, Next: CSHIFT, Prev: COUNT, Up: Intrinsic Procedures - -8.58 'CPU_TIME' -- CPU elapsed time in seconds -============================================== - -_Description_: - Returns a 'REAL' value representing the elapsed CPU time in - seconds. This is useful for testing segments of code to determine - execution time. - - If a time source is available, time will be reported with - microsecond resolution. If no time source is available, TIME is - set to '-1.0'. - - Note that TIME may contain a, system dependent, arbitrary offset - and may not start with '0.0'. For 'CPU_TIME', the absolute value - is meaningless, only differences between subsequent calls to this - subroutine, as shown in the example below, should be used. - -_Standard_: - Fortran 95 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL CPU_TIME(TIME)' - -_Arguments_: - TIME The type shall be 'REAL' with 'INTENT(OUT)'. - -_Return value_: - None - -_Example_: - program test_cpu_time - real :: start, finish - call cpu_time(start) - ! put code to test here - call cpu_time(finish) - print '("Time = ",f6.3," seconds.")',finish-start - end program test_cpu_time - -_See also_: - *note SYSTEM_CLOCK::, *note DATE_AND_TIME:: - - -File: gfortran.info, Node: CSHIFT, Next: CTIME, Prev: CPU_TIME, Up: Intrinsic Procedures - -8.59 'CSHIFT' -- Circular shift elements of an array -==================================================== - -_Description_: - 'CSHIFT(ARRAY, SHIFT [, DIM])' performs a circular shift on - elements of ARRAY along the dimension of DIM. If DIM is omitted it - is taken to be '1'. DIM is a scalar of type 'INTEGER' in the range - of 1 \leq DIM \leq n) where n is the rank of ARRAY. If the rank of - ARRAY is one, then all elements of ARRAY are shifted by SHIFT - places. If rank is greater than one, then all complete rank one - sections of ARRAY along the given dimension are shifted. Elements - shifted out one end of each rank one section are shifted back in - the other end. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = CSHIFT(ARRAY, SHIFT [, DIM])' - -_Arguments_: - ARRAY Shall be an array of any type. - SHIFT The type shall be 'INTEGER'. - DIM The type shall be 'INTEGER'. - -_Return value_: - Returns an array of same type and rank as the ARRAY argument. - -_Example_: - program test_cshift - integer, dimension(3,3) :: a - a = reshape( (/ 1, 2, 3, 4, 5, 6, 7, 8, 9 /), (/ 3, 3 /)) - print '(3i3)', a(1,:) - print '(3i3)', a(2,:) - print '(3i3)', a(3,:) - a = cshift(a, SHIFT=(/1, 2, -1/), DIM=2) - print * - print '(3i3)', a(1,:) - print '(3i3)', a(2,:) - print '(3i3)', a(3,:) - end program test_cshift - - -File: gfortran.info, Node: CTIME, Next: DATE_AND_TIME, Prev: CSHIFT, Up: Intrinsic Procedures - -8.60 'CTIME' -- Convert a time into a string -============================================ - -_Description_: - 'CTIME' converts a system time value, such as returned by 'TIME8', - to a string. Unless the application has called 'setlocale', the - output will be in the default locale, of length 24 and of the form - 'Sat Aug 19 18:13:14 1995'. In other locales, a longer string may - result. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL CTIME(TIME, RESULT)'. - 'RESULT = CTIME(TIME)'. - -_Arguments_: - TIME The type shall be of type 'INTEGER'. - RESULT The type shall be of type 'CHARACTER' and of - default kind. It is an 'INTENT(OUT)' argument. - If the length of this variable is too short for - the time and date string to fit completely, it - will be blank on procedure return. - -_Return value_: - The converted date and time as a string. - -_Example_: - program test_ctime - integer(8) :: i - character(len=30) :: date - i = time8() - - ! Do something, main part of the program - - call ctime(i,date) - print *, 'Program was started on ', date - end program test_ctime - -_See Also_: - *note DATE_AND_TIME::, *note GMTIME::, *note LTIME::, *note TIME::, - *note TIME8:: - - -File: gfortran.info, Node: DATE_AND_TIME, Next: DBLE, Prev: CTIME, Up: Intrinsic Procedures - -8.61 'DATE_AND_TIME' -- Date and time subroutine -================================================ - -_Description_: - 'DATE_AND_TIME(DATE, TIME, ZONE, VALUES)' gets the corresponding - date and time information from the real-time system clock. DATE is - 'INTENT(OUT)' and has form ccyymmdd. TIME is 'INTENT(OUT)' and has - form hhmmss.sss. ZONE is 'INTENT(OUT)' and has form (+-)hhmm, - representing the difference with respect to Coordinated Universal - Time (UTC). Unavailable time and date parameters return blanks. - - VALUES is 'INTENT(OUT)' and provides the following: - - 'VALUE(1)': The year - 'VALUE(2)': The month - 'VALUE(3)': The day of the month - 'VALUE(4)': Time difference with UTC in - minutes - 'VALUE(5)': The hour of the day - 'VALUE(6)': The minutes of the hour - 'VALUE(7)': The seconds of the minute - 'VALUE(8)': The milliseconds of the - second - -_Standard_: - Fortran 95 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL DATE_AND_TIME([DATE, TIME, ZONE, VALUES])' - -_Arguments_: - DATE (Optional) The type shall be 'CHARACTER(LEN=8)' - or larger, and of default kind. - TIME (Optional) The type shall be 'CHARACTER(LEN=10)' - or larger, and of default kind. - ZONE (Optional) The type shall be 'CHARACTER(LEN=5)' - or larger, and of default kind. - VALUES (Optional) The type shall be 'INTEGER(8)'. - -_Return value_: - None - -_Example_: - program test_time_and_date - character(8) :: date - character(10) :: time - character(5) :: zone - integer,dimension(8) :: values - ! using keyword arguments - call date_and_time(date,time,zone,values) - call date_and_time(DATE=date,ZONE=zone) - call date_and_time(TIME=time) - call date_and_time(VALUES=values) - print '(a,2x,a,2x,a)', date, time, zone - print '(8i5)', values - end program test_time_and_date - -_See also_: - *note CPU_TIME::, *note SYSTEM_CLOCK:: - - -File: gfortran.info, Node: DBLE, Next: DCMPLX, Prev: DATE_AND_TIME, Up: Intrinsic Procedures - -8.62 'DBLE' -- Double conversion function -========================================= - -_Description_: - 'DBLE(A)' Converts A to double precision real type. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = DBLE(A)' - -_Arguments_: - A The type shall be 'INTEGER', 'REAL', or - 'COMPLEX'. - -_Return value_: - The return value is of type double precision real. - -_Example_: - program test_dble - real :: x = 2.18 - integer :: i = 5 - complex :: z = (2.3,1.14) - print *, dble(x), dble(i), dble(z) - end program test_dble - -_See also_: - *note REAL:: - - -File: gfortran.info, Node: DCMPLX, Next: DIGITS, Prev: DBLE, Up: Intrinsic Procedures - -8.63 'DCMPLX' -- Double complex conversion function -=================================================== - -_Description_: - 'DCMPLX(X [,Y])' returns a double complex number where X is - converted to the real component. If Y is present it is converted - to the imaginary component. If Y is not present then the imaginary - component is set to 0.0. If X is complex then Y must not be - present. - -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = DCMPLX(X [, Y])' - -_Arguments_: - X The type may be 'INTEGER', 'REAL', or 'COMPLEX'. - Y (Optional if X is not 'COMPLEX'.) May be - 'INTEGER' or 'REAL'. - -_Return value_: - The return value is of type 'COMPLEX(8)' - -_Example_: - program test_dcmplx - integer :: i = 42 - real :: x = 3.14 - complex :: z - z = cmplx(i, x) - print *, dcmplx(i) - print *, dcmplx(x) - print *, dcmplx(z) - print *, dcmplx(x,i) - end program test_dcmplx - - -File: gfortran.info, Node: DIGITS, Next: DIM, Prev: DCMPLX, Up: Intrinsic Procedures - -8.64 'DIGITS' -- Significant binary digits function -=================================================== - -_Description_: - 'DIGITS(X)' returns the number of significant binary digits of the - internal model representation of X. For example, on a system using - a 32-bit floating point representation, a default real number would - likely return 24. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = DIGITS(X)' - -_Arguments_: - X The type may be 'INTEGER' or 'REAL'. - -_Return value_: - The return value is of type 'INTEGER'. - -_Example_: - program test_digits - integer :: i = 12345 - real :: x = 3.143 - real(8) :: y = 2.33 - print *, digits(i) - print *, digits(x) - print *, digits(y) - end program test_digits - - -File: gfortran.info, Node: DIM, Next: DOT_PRODUCT, Prev: DIGITS, Up: Intrinsic Procedures - -8.65 'DIM' -- Positive difference -================================= - -_Description_: - 'DIM(X,Y)' returns the difference 'X-Y' if the result is positive; - otherwise returns zero. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = DIM(X, Y)' - -_Arguments_: - X The type shall be 'INTEGER' or 'REAL' - Y The type shall be the same type and kind as X. - -_Return value_: - The return value is of type 'INTEGER' or 'REAL'. - -_Example_: - program test_dim - integer :: i - real(8) :: x - i = dim(4, 15) - x = dim(4.345_8, 2.111_8) - print *, i - print *, x - end program test_dim - -_Specific names_: - Name Argument Return type Standard - 'DIM(X,Y)' 'REAL(4) X, 'REAL(4)' Fortran 77 and - Y' later - 'IDIM(X,Y)' 'INTEGER(4) 'INTEGER(4)' Fortran 77 and - X, Y' later - 'DDIM(X,Y)' 'REAL(8) X, 'REAL(8)' Fortran 77 and - Y' later - - -File: gfortran.info, Node: DOT_PRODUCT, Next: DPROD, Prev: DIM, Up: Intrinsic Procedures - -8.66 'DOT_PRODUCT' -- Dot product function -========================================== - -_Description_: - 'DOT_PRODUCT(VECTOR_A, VECTOR_B)' computes the dot product - multiplication of two vectors VECTOR_A and VECTOR_B. The two - vectors may be either numeric or logical and must be arrays of rank - one and of equal size. If the vectors are 'INTEGER' or 'REAL', the - result is 'SUM(VECTOR_A*VECTOR_B)'. If the vectors are 'COMPLEX', - the result is 'SUM(CONJG(VECTOR_A)*VECTOR_B)'. If the vectors are - 'LOGICAL', the result is 'ANY(VECTOR_A .AND. VECTOR_B)'. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = DOT_PRODUCT(VECTOR_A, VECTOR_B)' - -_Arguments_: - VECTOR_A The type shall be numeric or 'LOGICAL', rank 1. - VECTOR_B The type shall be numeric if VECTOR_A is of - numeric type or 'LOGICAL' if VECTOR_A is of type - 'LOGICAL'. VECTOR_B shall be a rank-one array. - -_Return value_: - If the arguments are numeric, the return value is a scalar of - numeric type, 'INTEGER', 'REAL', or 'COMPLEX'. If the arguments - are 'LOGICAL', the return value is '.TRUE.' or '.FALSE.'. - -_Example_: - program test_dot_prod - integer, dimension(3) :: a, b - a = (/ 1, 2, 3 /) - b = (/ 4, 5, 6 /) - print '(3i3)', a - print * - print '(3i3)', b - print * - print *, dot_product(a,b) - end program test_dot_prod - - -File: gfortran.info, Node: DPROD, Next: DREAL, Prev: DOT_PRODUCT, Up: Intrinsic Procedures - -8.67 'DPROD' -- Double product function -======================================= - -_Description_: - 'DPROD(X,Y)' returns the product 'X*Y'. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = DPROD(X, Y)' - -_Arguments_: - X The type shall be 'REAL'. - Y The type shall be 'REAL'. - -_Return value_: - The return value is of type 'REAL(8)'. - -_Example_: - program test_dprod - real :: x = 5.2 - real :: y = 2.3 - real(8) :: d - d = dprod(x,y) - print *, d - end program test_dprod - -_Specific names_: - Name Argument Return type Standard - 'DPROD(X,Y)' 'REAL(4) X, 'REAL(4)' Fortran 77 and - Y' later - - -File: gfortran.info, Node: DREAL, Next: DSHIFTL, Prev: DPROD, Up: Intrinsic Procedures - -8.68 'DREAL' -- Double real part function -========================================= - -_Description_: - 'DREAL(Z)' returns the real part of complex variable Z. - -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = DREAL(A)' - -_Arguments_: - A The type shall be 'COMPLEX(8)'. - -_Return value_: - The return value is of type 'REAL(8)'. - -_Example_: - program test_dreal - complex(8) :: z = (1.3_8,7.2_8) - print *, dreal(z) - end program test_dreal - -_See also_: - *note AIMAG:: - - -File: gfortran.info, Node: DSHIFTL, Next: DSHIFTR, Prev: DREAL, Up: Intrinsic Procedures - -8.69 'DSHIFTL' -- Combined left shift -===================================== - -_Description_: - 'DSHIFTL(I, J, SHIFT)' combines bits of I and J. The rightmost - SHIFT bits of the result are the leftmost SHIFT bits of J, and the - remaining bits are the rightmost bits of I. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = DSHIFTL(I, J, SHIFT)' - -_Arguments_: - I Shall be of type 'INTEGER' or a BOZ constant. - J Shall be of type 'INTEGER' or a BOZ constant. - If both I and J have integer type, then they - shall have the same kind type parameter. I and - J shall not both be BOZ constants. - SHIFT Shall be of type 'INTEGER'. It shall be - nonnegative. If I is not a BOZ constant, then - SHIFT shall be less than or equal to - 'BIT_SIZE(I)'; otherwise, SHIFT shall be less - than or equal to 'BIT_SIZE(J)'. - -_Return value_: - If either I or J is a BOZ constant, it is first converted as if by - the intrinsic function 'INT' to an integer type with the kind type - parameter of the other. - -_See also_: - *note DSHIFTR:: - - -File: gfortran.info, Node: DSHIFTR, Next: DTIME, Prev: DSHIFTL, Up: Intrinsic Procedures - -8.70 'DSHIFTR' -- Combined right shift -====================================== - -_Description_: - 'DSHIFTR(I, J, SHIFT)' combines bits of I and J. The leftmost - SHIFT bits of the result are the rightmost SHIFT bits of I, and the - remaining bits are the leftmost bits of J. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = DSHIFTR(I, J, SHIFT)' - -_Arguments_: - I Shall be of type 'INTEGER' or a BOZ constant. - J Shall be of type 'INTEGER' or a BOZ constant. - If both I and J have integer type, then they - shall have the same kind type parameter. I and - J shall not both be BOZ constants. - SHIFT Shall be of type 'INTEGER'. It shall be - nonnegative. If I is not a BOZ constant, then - SHIFT shall be less than or equal to - 'BIT_SIZE(I)'; otherwise, SHIFT shall be less - than or equal to 'BIT_SIZE(J)'. - -_Return value_: - If either I or J is a BOZ constant, it is first converted as if by - the intrinsic function 'INT' to an integer type with the kind type - parameter of the other. - -_See also_: - *note DSHIFTL:: - - -File: gfortran.info, Node: DTIME, Next: EOSHIFT, Prev: DSHIFTR, Up: Intrinsic Procedures - -8.71 'DTIME' -- Execution time subroutine (or function) -======================================================= - -_Description_: - 'DTIME(VALUES, TIME)' initially returns the number of seconds of - runtime since the start of the process's execution in TIME. VALUES - returns the user and system components of this time in 'VALUES(1)' - and 'VALUES(2)' respectively. TIME is equal to 'VALUES(1) + - VALUES(2)'. - - Subsequent invocations of 'DTIME' return values accumulated since - the previous invocation. - - On some systems, the underlying timings are represented using types - with sufficiently small limits that overflows (wrap around) are - possible, such as 32-bit types. Therefore, the values returned by - this intrinsic might be, or become, negative, or numerically less - than previous values, during a single run of the compiled program. - - Please note, that this implementation is thread safe if used within - OpenMP directives, i.e., its state will be consistent while called - from multiple threads. However, if 'DTIME' is called from multiple - threads, the result is still the time since the last invocation. - This may not give the intended results. If possible, use - 'CPU_TIME' instead. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - - VALUES and TIME are 'INTENT(OUT)' and provide the following: - - 'VALUES(1)': User time in seconds. - 'VALUES(2)': System time in seconds. - 'TIME': Run time since start in - seconds. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL DTIME(VALUES, TIME)'. - 'TIME = DTIME(VALUES)', (not recommended). - -_Arguments_: - VALUES The type shall be 'REAL(4), DIMENSION(2)'. - TIME The type shall be 'REAL(4)'. - -_Return value_: - Elapsed time in seconds since the last invocation or since the - start of program execution if not called before. - -_Example_: - program test_dtime - integer(8) :: i, j - real, dimension(2) :: tarray - real :: result - call dtime(tarray, result) - print *, result - print *, tarray(1) - print *, tarray(2) - do i=1,100000000 ! Just a delay - j = i * i - i - end do - call dtime(tarray, result) - print *, result - print *, tarray(1) - print *, tarray(2) - end program test_dtime - -_See also_: - *note CPU_TIME:: - - -File: gfortran.info, Node: EOSHIFT, Next: EPSILON, Prev: DTIME, Up: Intrinsic Procedures - -8.72 'EOSHIFT' -- End-off shift elements of an array -==================================================== - -_Description_: - 'EOSHIFT(ARRAY, SHIFT[, BOUNDARY, DIM])' performs an end-off shift - on elements of ARRAY along the dimension of DIM. If DIM is omitted - it is taken to be '1'. DIM is a scalar of type 'INTEGER' in the - range of 1 \leq DIM \leq n) where n is the rank of ARRAY. If the - rank of ARRAY is one, then all elements of ARRAY are shifted by - SHIFT places. If rank is greater than one, then all complete rank - one sections of ARRAY along the given dimension are shifted. - Elements shifted out one end of each rank one section are dropped. - If BOUNDARY is present then the corresponding value of from - BOUNDARY is copied back in the other end. If BOUNDARY is not - present then the following are copied in depending on the type of - ARRAY. - - _Array _Boundary Value_ - Type_ - Numeric 0 of the type and kind of ARRAY. - Logical '.FALSE.'. - Character(LEN)LEN blanks. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = EOSHIFT(ARRAY, SHIFT [, BOUNDARY, DIM])' - -_Arguments_: - ARRAY May be any type, not scalar. - SHIFT The type shall be 'INTEGER'. - BOUNDARY Same type as ARRAY. - DIM The type shall be 'INTEGER'. - -_Return value_: - Returns an array of same type and rank as the ARRAY argument. - -_Example_: - program test_eoshift - integer, dimension(3,3) :: a - a = reshape( (/ 1, 2, 3, 4, 5, 6, 7, 8, 9 /), (/ 3, 3 /)) - print '(3i3)', a(1,:) - print '(3i3)', a(2,:) - print '(3i3)', a(3,:) - a = EOSHIFT(a, SHIFT=(/1, 2, 1/), BOUNDARY=-5, DIM=2) - print * - print '(3i3)', a(1,:) - print '(3i3)', a(2,:) - print '(3i3)', a(3,:) - end program test_eoshift - - -File: gfortran.info, Node: EPSILON, Next: ERF, Prev: EOSHIFT, Up: Intrinsic Procedures - -8.73 'EPSILON' -- Epsilon function -================================== - -_Description_: - 'EPSILON(X)' returns the smallest number E of the same kind as X - such that 1 + E > 1. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = EPSILON(X)' - -_Arguments_: - X The type shall be 'REAL'. - -_Return value_: - The return value is of same type as the argument. - -_Example_: - program test_epsilon - real :: x = 3.143 - real(8) :: y = 2.33 - print *, EPSILON(x) - print *, EPSILON(y) - end program test_epsilon - - -File: gfortran.info, Node: ERF, Next: ERFC, Prev: EPSILON, Up: Intrinsic Procedures - -8.74 'ERF' -- Error function -============================ - -_Description_: - 'ERF(X)' computes the error function of X. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ERF(X)' - -_Arguments_: - X The type shall be 'REAL'. - -_Return value_: - The return value is of type 'REAL', of the same kind as X and lies - in the range -1 \leq erf (x) \leq 1 . - -_Example_: - program test_erf - real(8) :: x = 0.17_8 - x = erf(x) - end program test_erf - -_Specific names_: - Name Argument Return type Standard - 'DERF(X)' 'REAL(8) X' 'REAL(8)' GNU extension - - -File: gfortran.info, Node: ERFC, Next: ERFC_SCALED, Prev: ERF, Up: Intrinsic Procedures - -8.75 'ERFC' -- Error function -============================= - -_Description_: - 'ERFC(X)' computes the complementary error function of X. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ERFC(X)' - -_Arguments_: - X The type shall be 'REAL'. - -_Return value_: - The return value is of type 'REAL' and of the same kind as X. It - lies in the range 0 \leq erfc (x) \leq 2 . - -_Example_: - program test_erfc - real(8) :: x = 0.17_8 - x = erfc(x) - end program test_erfc - -_Specific names_: - Name Argument Return type Standard - 'DERFC(X)' 'REAL(8) X' 'REAL(8)' GNU extension - - -File: gfortran.info, Node: ERFC_SCALED, Next: ETIME, Prev: ERFC, Up: Intrinsic Procedures - -8.76 'ERFC_SCALED' -- Error function -==================================== - -_Description_: - 'ERFC_SCALED(X)' computes the exponentially-scaled complementary - error function of X. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ERFC_SCALED(X)' - -_Arguments_: - X The type shall be 'REAL'. - -_Return value_: - The return value is of type 'REAL' and of the same kind as X. - -_Example_: - program test_erfc_scaled - real(8) :: x = 0.17_8 - x = erfc_scaled(x) - end program test_erfc_scaled - - -File: gfortran.info, Node: ETIME, Next: EXECUTE_COMMAND_LINE, Prev: ERFC_SCALED, Up: Intrinsic Procedures - -8.77 'ETIME' -- Execution time subroutine (or function) -======================================================= - -_Description_: - 'ETIME(VALUES, TIME)' returns the number of seconds of runtime - since the start of the process's execution in TIME. VALUES returns - the user and system components of this time in 'VALUES(1)' and - 'VALUES(2)' respectively. TIME is equal to 'VALUES(1) + - VALUES(2)'. - - On some systems, the underlying timings are represented using types - with sufficiently small limits that overflows (wrap around) are - possible, such as 32-bit types. Therefore, the values returned by - this intrinsic might be, or become, negative, or numerically less - than previous values, during a single run of the compiled program. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - - VALUES and TIME are 'INTENT(OUT)' and provide the following: - - 'VALUES(1)': User time in seconds. - 'VALUES(2)': System time in seconds. - 'TIME': Run time since start in seconds. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL ETIME(VALUES, TIME)'. - 'TIME = ETIME(VALUES)', (not recommended). - -_Arguments_: - VALUES The type shall be 'REAL(4), DIMENSION(2)'. - TIME The type shall be 'REAL(4)'. - -_Return value_: - Elapsed time in seconds since the start of program execution. - -_Example_: - program test_etime - integer(8) :: i, j - real, dimension(2) :: tarray - real :: result - call ETIME(tarray, result) - print *, result - print *, tarray(1) - print *, tarray(2) - do i=1,100000000 ! Just a delay - j = i * i - i - end do - call ETIME(tarray, result) - print *, result - print *, tarray(1) - print *, tarray(2) - end program test_etime - -_See also_: - *note CPU_TIME:: - - -File: gfortran.info, Node: EXECUTE_COMMAND_LINE, Next: EXIT, Prev: ETIME, Up: Intrinsic Procedures - -8.78 'EXECUTE_COMMAND_LINE' -- Execute a shell command -====================================================== - -_Description_: - 'EXECUTE_COMMAND_LINE' runs a shell command, synchronously or - asynchronously. - - The 'COMMAND' argument is passed to the shell and executed, using - the C library's 'system' call. (The shell is 'sh' on Unix systems, - and 'cmd.exe' on Windows.) If 'WAIT' is present and has the value - false, the execution of the command is asynchronous if the system - supports it; otherwise, the command is executed synchronously. - - The three last arguments allow the user to get status information. - After synchronous execution, 'EXITSTAT' contains the integer exit - code of the command, as returned by 'system'. 'CMDSTAT' is set to - zero if the command line was executed (whatever its exit status - was). 'CMDMSG' is assigned an error message if an error has - occurred. - - Note that the 'system' function need not be thread-safe. It is the - responsibility of the user to ensure that 'system' is not called - concurrently. - -_Standard_: - Fortran 2008 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL EXECUTE_COMMAND_LINE(COMMAND [, WAIT, EXITSTAT, CMDSTAT, - CMDMSG ])' - -_Arguments_: - COMMAND Shall be a default 'CHARACTER' scalar. - WAIT (Optional) Shall be a default 'LOGICAL' scalar. - EXITSTAT (Optional) Shall be an 'INTEGER' of the default - kind. - CMDSTAT (Optional) Shall be an 'INTEGER' of the default - kind. - CMDMSG (Optional) Shall be an 'CHARACTER' scalar of the - default kind. - -_Example_: - program test_exec - integer :: i - - call execute_command_line ("external_prog.exe", exitstat=i) - print *, "Exit status of external_prog.exe was ", i - - call execute_command_line ("reindex_files.exe", wait=.false.) - print *, "Now reindexing files in the background" - - end program test_exec - -_Note_: - - Because this intrinsic is implemented in terms of the 'system' - function call, its behavior with respect to signaling is processor - dependent. In particular, on POSIX-compliant systems, the SIGINT - and SIGQUIT signals will be ignored, and the SIGCHLD will be - blocked. As such, if the parent process is terminated, the child - process might not be terminated alongside. - -_See also_: - *note SYSTEM:: - - -File: gfortran.info, Node: EXIT, Next: EXP, Prev: EXECUTE_COMMAND_LINE, Up: Intrinsic Procedures - -8.79 'EXIT' -- Exit the program with status. -============================================ - -_Description_: - 'EXIT' causes immediate termination of the program with status. If - status is omitted it returns the canonical _success_ for the - system. All Fortran I/O units are closed. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL EXIT([STATUS])' - -_Arguments_: - STATUS Shall be an 'INTEGER' of the default kind. - -_Return value_: - 'STATUS' is passed to the parent process on exit. - -_Example_: - program test_exit - integer :: STATUS = 0 - print *, 'This program is going to exit.' - call EXIT(STATUS) - end program test_exit - -_See also_: - *note ABORT::, *note KILL:: - - -File: gfortran.info, Node: EXP, Next: EXPONENT, Prev: EXIT, Up: Intrinsic Procedures - -8.80 'EXP' -- Exponential function -================================== - -_Description_: - 'EXP(X)' computes the base e exponential of X. - -_Standard_: - Fortran 77 and later, has overloads that are GNU extensions - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = EXP(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value has same type and kind as X. - -_Example_: - program test_exp - real :: x = 1.0 - x = exp(x) - end program test_exp - -_Specific names_: - Name Argument Return type Standard - 'EXP(X)' 'REAL(4) X' 'REAL(4)' Fortran 77 and - later - 'DEXP(X)' 'REAL(8) X' 'REAL(8)' Fortran 77 and - later - 'CEXP(X)' 'COMPLEX(4) 'COMPLEX(4)' Fortran 77 and - X' later - 'ZEXP(X)' 'COMPLEX(8) 'COMPLEX(8)' GNU extension - X' - 'CDEXP(X)' 'COMPLEX(8) 'COMPLEX(8)' GNU extension - X' - - -File: gfortran.info, Node: EXPONENT, Next: EXTENDS_TYPE_OF, Prev: EXP, Up: Intrinsic Procedures - -8.81 'EXPONENT' -- Exponent function -==================================== - -_Description_: - 'EXPONENT(X)' returns the value of the exponent part of X. If X is - zero the value returned is zero. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = EXPONENT(X)' - -_Arguments_: - X The type shall be 'REAL'. - -_Return value_: - The return value is of type default 'INTEGER'. - -_Example_: - program test_exponent - real :: x = 1.0 - integer :: i - i = exponent(x) - print *, i - print *, exponent(0.0) - end program test_exponent - - -File: gfortran.info, Node: EXTENDS_TYPE_OF, Next: FDATE, Prev: EXPONENT, Up: Intrinsic Procedures - -8.82 'EXTENDS_TYPE_OF' -- Query dynamic type for extension -========================================================== - -_Description_: - Query dynamic type for extension. - -_Standard_: - Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = EXTENDS_TYPE_OF(A, MOLD)' - -_Arguments_: - A Shall be an object of extensible declared type - or unlimited polymorphic. - MOLD Shall be an object of extensible declared type - or unlimited polymorphic. - -_Return value_: - The return value is a scalar of type default logical. It is true - if and only if the dynamic type of A is an extension type of the - dynamic type of MOLD. - -_See also_: - *note SAME_TYPE_AS:: - - -File: gfortran.info, Node: FDATE, Next: FGET, Prev: EXTENDS_TYPE_OF, Up: Intrinsic Procedures - -8.83 'FDATE' -- Get the current time as a string -================================================ - -_Description_: - 'FDATE(DATE)' returns the current date (using the same format as - 'CTIME') in DATE. It is equivalent to 'CALL CTIME(DATE, TIME())'. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL FDATE(DATE)'. - 'DATE = FDATE()'. - -_Arguments_: - DATE The type shall be of type 'CHARACTER' of the - default kind. It is an 'INTENT(OUT)' argument. - If the length of this variable is too short for - the date and time string to fit completely, it - will be blank on procedure return. - -_Return value_: - The current date and time as a string. - -_Example_: - program test_fdate - integer(8) :: i, j - character(len=30) :: date - call fdate(date) - print *, 'Program started on ', date - do i = 1, 100000000 ! Just a delay - j = i * i - i - end do - call fdate(date) - print *, 'Program ended on ', date - end program test_fdate - -_See also_: - *note DATE_AND_TIME::, *note CTIME:: - - -File: gfortran.info, Node: FGET, Next: FGETC, Prev: FDATE, Up: Intrinsic Procedures - -8.84 'FGET' -- Read a single character in stream mode from stdin -================================================================ - -_Description_: - Read a single character in stream mode from stdin by bypassing - normal formatted output. Stream I/O should not be mixed with - normal record-oriented (formatted or unformatted) I/O on the same - unit; the results are unpredictable. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - - Note that the 'FGET' intrinsic is provided for backwards - compatibility with 'g77'. GNU Fortran provides the Fortran 2003 - Stream facility. Programmers should consider the use of new stream - IO feature in new code for future portability. See also *note - Fortran 2003 status::. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL FGET(C [, STATUS])' - 'STATUS = FGET(C)' - -_Arguments_: - C The type shall be 'CHARACTER' and of default - kind. - STATUS (Optional) status flag of type 'INTEGER'. - Returns 0 on success, -1 on end-of-file, and a - system specific positive error code otherwise. - -_Example_: - PROGRAM test_fget - INTEGER, PARAMETER :: strlen = 100 - INTEGER :: status, i = 1 - CHARACTER(len=strlen) :: str = "" - - WRITE (*,*) 'Enter text:' - DO - CALL fget(str(i:i), status) - if (status /= 0 .OR. i > strlen) exit - i = i + 1 - END DO - WRITE (*,*) TRIM(str) - END PROGRAM - -_See also_: - *note FGETC::, *note FPUT::, *note FPUTC:: - - -File: gfortran.info, Node: FGETC, Next: FLOOR, Prev: FGET, Up: Intrinsic Procedures - -8.85 'FGETC' -- Read a single character in stream mode -====================================================== - -_Description_: - Read a single character in stream mode by bypassing normal - formatted output. Stream I/O should not be mixed with normal - record-oriented (formatted or unformatted) I/O on the same unit; - the results are unpredictable. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - - Note that the 'FGET' intrinsic is provided for backwards - compatibility with 'g77'. GNU Fortran provides the Fortran 2003 - Stream facility. Programmers should consider the use of new stream - IO feature in new code for future portability. See also *note - Fortran 2003 status::. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL FGETC(UNIT, C [, STATUS])' - 'STATUS = FGETC(UNIT, C)' - -_Arguments_: - UNIT The type shall be 'INTEGER'. - C The type shall be 'CHARACTER' and of default - kind. - STATUS (Optional) status flag of type 'INTEGER'. - Returns 0 on success, -1 on end-of-file and a - system specific positive error code otherwise. - -_Example_: - PROGRAM test_fgetc - INTEGER :: fd = 42, status - CHARACTER :: c - - OPEN(UNIT=fd, FILE="/etc/passwd", ACTION="READ", STATUS = "OLD") - DO - CALL fgetc(fd, c, status) - IF (status /= 0) EXIT - call fput(c) - END DO - CLOSE(UNIT=fd) - END PROGRAM - -_See also_: - *note FGET::, *note FPUT::, *note FPUTC:: - - -File: gfortran.info, Node: FLOOR, Next: FLUSH, Prev: FGETC, Up: Intrinsic Procedures - -8.86 'FLOOR' -- Integer floor function -====================================== - -_Description_: - 'FLOOR(A)' returns the greatest integer less than or equal to X. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = FLOOR(A [, KIND])' - -_Arguments_: - A The type shall be 'REAL'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER(KIND)' if KIND is present and - of default-kind 'INTEGER' otherwise. - -_Example_: - program test_floor - real :: x = 63.29 - real :: y = -63.59 - print *, floor(x) ! returns 63 - print *, floor(y) ! returns -64 - end program test_floor - -_See also_: - *note CEILING::, *note NINT:: - - -File: gfortran.info, Node: FLUSH, Next: FNUM, Prev: FLOOR, Up: Intrinsic Procedures - -8.87 'FLUSH' -- Flush I/O unit(s) -================================= - -_Description_: - Flushes Fortran unit(s) currently open for output. Without the - optional argument, all units are flushed, otherwise just the unit - specified. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL FLUSH(UNIT)' - -_Arguments_: - UNIT (Optional) The type shall be 'INTEGER'. - -_Note_: - Beginning with the Fortran 2003 standard, there is a 'FLUSH' - statement that should be preferred over the 'FLUSH' intrinsic. - - The 'FLUSH' intrinsic and the Fortran 2003 'FLUSH' statement have - identical effect: they flush the runtime library's I/O buffer so - that the data becomes visible to other processes. This does not - guarantee that the data is committed to disk. - - On POSIX systems, you can request that all data is transferred to - the storage device by calling the 'fsync' function, with the POSIX - file descriptor of the I/O unit as argument (retrieved with GNU - intrinsic 'FNUM'). The following example shows how: - - ! Declare the interface for POSIX fsync function - interface - function fsync (fd) bind(c,name="fsync") - use iso_c_binding, only: c_int - integer(c_int), value :: fd - integer(c_int) :: fsync - end function fsync - end interface - - ! Variable declaration - integer :: ret - - ! Opening unit 10 - open (10,file="foo") - - ! ... - ! Perform I/O on unit 10 - ! ... - - ! Flush and sync - flush(10) - ret = fsync(fnum(10)) - - ! Handle possible error - if (ret /= 0) stop "Error calling FSYNC" - - -File: gfortran.info, Node: FNUM, Next: FPUT, Prev: FLUSH, Up: Intrinsic Procedures - -8.88 'FNUM' -- File number function -=================================== - -_Description_: - 'FNUM(UNIT)' returns the POSIX file descriptor number corresponding - to the open Fortran I/O unit 'UNIT'. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = FNUM(UNIT)' - -_Arguments_: - UNIT The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' - -_Example_: - program test_fnum - integer :: i - open (unit=10, status = "scratch") - i = fnum(10) - print *, i - close (10) - end program test_fnum - - -File: gfortran.info, Node: FPUT, Next: FPUTC, Prev: FNUM, Up: Intrinsic Procedures - -8.89 'FPUT' -- Write a single character in stream mode to stdout -================================================================ - -_Description_: - Write a single character in stream mode to stdout by bypassing - normal formatted output. Stream I/O should not be mixed with - normal record-oriented (formatted or unformatted) I/O on the same - unit; the results are unpredictable. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - - Note that the 'FGET' intrinsic is provided for backwards - compatibility with 'g77'. GNU Fortran provides the Fortran 2003 - Stream facility. Programmers should consider the use of new stream - IO feature in new code for future portability. See also *note - Fortran 2003 status::. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL FPUT(C [, STATUS])' - 'STATUS = FPUT(C)' - -_Arguments_: - C The type shall be 'CHARACTER' and of default - kind. - STATUS (Optional) status flag of type 'INTEGER'. - Returns 0 on success, -1 on end-of-file and a - system specific positive error code otherwise. - -_Example_: - PROGRAM test_fput - CHARACTER(len=10) :: str = "gfortran" - INTEGER :: i - DO i = 1, len_trim(str) - CALL fput(str(i:i)) - END DO - END PROGRAM - -_See also_: - *note FPUTC::, *note FGET::, *note FGETC:: - - -File: gfortran.info, Node: FPUTC, Next: FRACTION, Prev: FPUT, Up: Intrinsic Procedures - -8.90 'FPUTC' -- Write a single character in stream mode -======================================================= - -_Description_: - Write a single character in stream mode by bypassing normal - formatted output. Stream I/O should not be mixed with normal - record-oriented (formatted or unformatted) I/O on the same unit; - the results are unpredictable. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - - Note that the 'FGET' intrinsic is provided for backwards - compatibility with 'g77'. GNU Fortran provides the Fortran 2003 - Stream facility. Programmers should consider the use of new stream - IO feature in new code for future portability. See also *note - Fortran 2003 status::. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL FPUTC(UNIT, C [, STATUS])' - 'STATUS = FPUTC(UNIT, C)' - -_Arguments_: - UNIT The type shall be 'INTEGER'. - C The type shall be 'CHARACTER' and of default - kind. - STATUS (Optional) status flag of type 'INTEGER'. - Returns 0 on success, -1 on end-of-file and a - system specific positive error code otherwise. - -_Example_: - PROGRAM test_fputc - CHARACTER(len=10) :: str = "gfortran" - INTEGER :: fd = 42, i - - OPEN(UNIT = fd, FILE = "out", ACTION = "WRITE", STATUS="NEW") - DO i = 1, len_trim(str) - CALL fputc(fd, str(i:i)) - END DO - CLOSE(fd) - END PROGRAM - -_See also_: - *note FPUT::, *note FGET::, *note FGETC:: - - -File: gfortran.info, Node: FRACTION, Next: FREE, Prev: FPUTC, Up: Intrinsic Procedures - -8.91 'FRACTION' -- Fractional part of the model representation -============================================================== - -_Description_: - 'FRACTION(X)' returns the fractional part of the model - representation of 'X'. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'Y = FRACTION(X)' - -_Arguments_: - X The type of the argument shall be a 'REAL'. - -_Return value_: - The return value is of the same type and kind as the argument. The - fractional part of the model representation of 'X' is returned; it - is 'X * RADIX(X)**(-EXPONENT(X))'. - -_Example_: - program test_fraction - real :: x - x = 178.1387e-4 - print *, fraction(x), x * radix(x)**(-exponent(x)) - end program test_fraction - - -File: gfortran.info, Node: FREE, Next: FSEEK, Prev: FRACTION, Up: Intrinsic Procedures - -8.92 'FREE' -- Frees memory -=========================== - -_Description_: - Frees memory previously allocated by 'MALLOC'. The 'FREE' - intrinsic is an extension intended to be used with Cray pointers, - and is provided in GNU Fortran to allow user to compile legacy - code. For new code using Fortran 95 pointers, the memory - de-allocation intrinsic is 'DEALLOCATE'. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL FREE(PTR)' - -_Arguments_: - PTR The type shall be 'INTEGER'. It represents the - location of the memory that should be - de-allocated. - -_Return value_: - None - -_Example_: - See 'MALLOC' for an example. - -_See also_: - *note MALLOC:: - - -File: gfortran.info, Node: FSEEK, Next: FSTAT, Prev: FREE, Up: Intrinsic Procedures - -8.93 'FSEEK' -- Low level file positioning subroutine -===================================================== - -_Description_: - Moves UNIT to the specified OFFSET. If WHENCE is set to 0, the - OFFSET is taken as an absolute value 'SEEK_SET', if set to 1, - OFFSET is taken to be relative to the current position 'SEEK_CUR', - and if set to 2 relative to the end of the file 'SEEK_END'. On - error, STATUS is set to a nonzero value. If STATUS the seek fails - silently. - - This intrinsic routine is not fully backwards compatible with - 'g77'. In 'g77', the 'FSEEK' takes a statement label instead of a - STATUS variable. If FSEEK is used in old code, change - CALL FSEEK(UNIT, OFFSET, WHENCE, *label) - to - INTEGER :: status - CALL FSEEK(UNIT, OFFSET, WHENCE, status) - IF (status /= 0) GOTO label - - Please note that GNU Fortran provides the Fortran 2003 Stream - facility. Programmers should consider the use of new stream IO - feature in new code for future portability. See also *note Fortran - 2003 status::. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL FSEEK(UNIT, OFFSET, WHENCE[, STATUS])' - -_Arguments_: - UNIT Shall be a scalar of type 'INTEGER'. - OFFSET Shall be a scalar of type 'INTEGER'. - WHENCE Shall be a scalar of type 'INTEGER'. Its value - shall be either 0, 1 or 2. - STATUS (Optional) shall be a scalar of type - 'INTEGER(4)'. - -_Example_: - PROGRAM test_fseek - INTEGER, PARAMETER :: SEEK_SET = 0, SEEK_CUR = 1, SEEK_END = 2 - INTEGER :: fd, offset, ierr - - ierr = 0 - offset = 5 - fd = 10 - - OPEN(UNIT=fd, FILE="fseek.test") - CALL FSEEK(fd, offset, SEEK_SET, ierr) ! move to OFFSET - print *, FTELL(fd), ierr - - CALL FSEEK(fd, 0, SEEK_END, ierr) ! move to end - print *, FTELL(fd), ierr - - CALL FSEEK(fd, 0, SEEK_SET, ierr) ! move to beginning - print *, FTELL(fd), ierr - - CLOSE(UNIT=fd) - END PROGRAM - -_See also_: - *note FTELL:: - - -File: gfortran.info, Node: FSTAT, Next: FTELL, Prev: FSEEK, Up: Intrinsic Procedures - -8.94 'FSTAT' -- Get file status -=============================== - -_Description_: - 'FSTAT' is identical to *note STAT::, except that information about - an already opened file is obtained. - - The elements in 'VALUES' are the same as described by *note STAT::. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL FSTAT(UNIT, VALUES [, STATUS])' - 'STATUS = FSTAT(UNIT, VALUES)' - -_Arguments_: - UNIT An open I/O unit number of type 'INTEGER'. - VALUES The type shall be 'INTEGER(4), DIMENSION(13)'. - STATUS (Optional) status flag of type 'INTEGER(4)'. - Returns 0 on success and a system specific error - code otherwise. - -_Example_: - See *note STAT:: for an example. - -_See also_: - To stat a link: *note LSTAT::, to stat a file: *note STAT:: - - -File: gfortran.info, Node: FTELL, Next: GAMMA, Prev: FSTAT, Up: Intrinsic Procedures - -8.95 'FTELL' -- Current stream position -======================================= - -_Description_: - Retrieves the current position within an open file. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL FTELL(UNIT, OFFSET)' - 'OFFSET = FTELL(UNIT)' - -_Arguments_: - OFFSET Shall of type 'INTEGER'. - UNIT Shall of type 'INTEGER'. - -_Return value_: - In either syntax, OFFSET is set to the current offset of unit - number UNIT, or to -1 if the unit is not currently open. - -_Example_: - PROGRAM test_ftell - INTEGER :: i - OPEN(10, FILE="temp.dat") - CALL ftell(10,i) - WRITE(*,*) i - END PROGRAM - -_See also_: - *note FSEEK:: - - -File: gfortran.info, Node: GAMMA, Next: GERROR, Prev: FTELL, Up: Intrinsic Procedures - -8.96 'GAMMA' -- Gamma function -============================== - -_Description_: - 'GAMMA(X)' computes Gamma (\Gamma) of X. For positive, integer - values of X the Gamma function simplifies to the factorial function - \Gamma(x)=(x-1)!. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'X = GAMMA(X)' - -_Arguments_: - X Shall be of type 'REAL' and neither zero nor a - negative integer. - -_Return value_: - The return value is of type 'REAL' of the same kind as X. - -_Example_: - program test_gamma - real :: x = 1.0 - x = gamma(x) ! returns 1.0 - end program test_gamma - -_Specific names_: - Name Argument Return type Standard - 'GAMMA(X)' 'REAL(4) X' 'REAL(4)' GNU Extension - 'DGAMMA(X)' 'REAL(8) X' 'REAL(8)' GNU Extension - -_See also_: - Logarithm of the Gamma function: *note LOG_GAMMA:: - - -File: gfortran.info, Node: GERROR, Next: GETARG, Prev: GAMMA, Up: Intrinsic Procedures - -8.97 'GERROR' -- Get last system error message -============================================== - -_Description_: - Returns the system error message corresponding to the last system - error. This resembles the functionality of 'strerror(3)' in C. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL GERROR(RESULT)' - -_Arguments_: - RESULT Shall of type 'CHARACTER' and of default - -_Example_: - PROGRAM test_gerror - CHARACTER(len=100) :: msg - CALL gerror(msg) - WRITE(*,*) msg - END PROGRAM - -_See also_: - *note IERRNO::, *note PERROR:: - - -File: gfortran.info, Node: GETARG, Next: GET_COMMAND, Prev: GERROR, Up: Intrinsic Procedures - -8.98 'GETARG' -- Get command line arguments -=========================================== - -_Description_: - Retrieve the POS-th argument that was passed on the command line - when the containing program was invoked. - - This intrinsic routine is provided for backwards compatibility with - GNU Fortran 77. In new code, programmers should consider the use - of the *note GET_COMMAND_ARGUMENT:: intrinsic defined by the - Fortran 2003 standard. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL GETARG(POS, VALUE)' - -_Arguments_: - POS Shall be of type 'INTEGER' and not wider than - the default integer kind; POS \geq 0 - VALUE Shall be of type 'CHARACTER' and of default - kind. - VALUE Shall be of type 'CHARACTER'. - -_Return value_: - After 'GETARG' returns, the VALUE argument holds the POSth command - line argument. If VALUE can not hold the argument, it is truncated - to fit the length of VALUE. If there are less than POS arguments - specified at the command line, VALUE will be filled with blanks. - If POS = 0, VALUE is set to the name of the program (on systems - that support this feature). - -_Example_: - PROGRAM test_getarg - INTEGER :: i - CHARACTER(len=32) :: arg - - DO i = 1, iargc() - CALL getarg(i, arg) - WRITE (*,*) arg - END DO - END PROGRAM - -_See also_: - GNU Fortran 77 compatibility function: *note IARGC:: - - Fortran 2003 functions and subroutines: *note GET_COMMAND::, *note - GET_COMMAND_ARGUMENT::, *note COMMAND_ARGUMENT_COUNT:: - - -File: gfortran.info, Node: GET_COMMAND, Next: GET_COMMAND_ARGUMENT, Prev: GETARG, Up: Intrinsic Procedures - -8.99 'GET_COMMAND' -- Get the entire command line -================================================= - -_Description_: - Retrieve the entire command line that was used to invoke the - program. - -_Standard_: - Fortran 2003 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL GET_COMMAND([COMMAND, LENGTH, STATUS])' - -_Arguments_: - COMMAND (Optional) shall be of type 'CHARACTER' and of - default kind. - LENGTH (Optional) Shall be of type 'INTEGER' and of - default kind. - STATUS (Optional) Shall be of type 'INTEGER' and of - default kind. - -_Return value_: - If COMMAND is present, stores the entire command line that was used - to invoke the program in COMMAND. If LENGTH is present, it is - assigned the length of the command line. If STATUS is present, it - is assigned 0 upon success of the command, -1 if COMMAND is too - short to store the command line, or a positive value in case of an - error. - -_Example_: - PROGRAM test_get_command - CHARACTER(len=255) :: cmd - CALL get_command(cmd) - WRITE (*,*) TRIM(cmd) - END PROGRAM - -_See also_: - *note GET_COMMAND_ARGUMENT::, *note COMMAND_ARGUMENT_COUNT:: - - -File: gfortran.info, Node: GET_COMMAND_ARGUMENT, Next: GETCWD, Prev: GET_COMMAND, Up: Intrinsic Procedures - -8.100 'GET_COMMAND_ARGUMENT' -- Get command line arguments -========================================================== - -_Description_: - Retrieve the NUMBER-th argument that was passed on the command line - when the containing program was invoked. - -_Standard_: - Fortran 2003 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL GET_COMMAND_ARGUMENT(NUMBER [, VALUE, LENGTH, STATUS])' - -_Arguments_: - NUMBER Shall be a scalar of type 'INTEGER' and of - default kind, NUMBER \geq 0 - VALUE (Optional) Shall be a scalar of type 'CHARACTER' - and of default kind. - LENGTH (Optional) Shall be a scalar of type 'INTEGER' - and of default kind. - STATUS (Optional) Shall be a scalar of type 'INTEGER' - and of default kind. - -_Return value_: - After 'GET_COMMAND_ARGUMENT' returns, the VALUE argument holds the - NUMBER-th command line argument. If VALUE can not hold the - argument, it is truncated to fit the length of VALUE. If there are - less than NUMBER arguments specified at the command line, VALUE - will be filled with blanks. If NUMBER = 0, VALUE is set to the - name of the program (on systems that support this feature). The - LENGTH argument contains the length of the NUMBER-th command line - argument. If the argument retrieval fails, STATUS is a positive - number; if VALUE contains a truncated command line argument, STATUS - is -1; and otherwise the STATUS is zero. - -_Example_: - PROGRAM test_get_command_argument - INTEGER :: i - CHARACTER(len=32) :: arg - - i = 0 - DO - CALL get_command_argument(i, arg) - IF (LEN_TRIM(arg) == 0) EXIT - - WRITE (*,*) TRIM(arg) - i = i+1 - END DO - END PROGRAM - -_See also_: - *note GET_COMMAND::, *note COMMAND_ARGUMENT_COUNT:: - - -File: gfortran.info, Node: GETCWD, Next: GETENV, Prev: GET_COMMAND_ARGUMENT, Up: Intrinsic Procedures - -8.101 'GETCWD' -- Get current working directory -=============================================== - -_Description_: - Get current working directory. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL GETCWD(C [, STATUS])' - 'STATUS = GETCWD(C)' - -_Arguments_: - C The type shall be 'CHARACTER' and of default - kind. - STATUS (Optional) status flag. Returns 0 on success, a - system specific and nonzero error code - otherwise. - -_Example_: - PROGRAM test_getcwd - CHARACTER(len=255) :: cwd - CALL getcwd(cwd) - WRITE(*,*) TRIM(cwd) - END PROGRAM - -_See also_: - *note CHDIR:: - - -File: gfortran.info, Node: GETENV, Next: GET_ENVIRONMENT_VARIABLE, Prev: GETCWD, Up: Intrinsic Procedures - -8.102 'GETENV' -- Get an environmental variable -=============================================== - -_Description_: - Get the VALUE of the environmental variable NAME. - - This intrinsic routine is provided for backwards compatibility with - GNU Fortran 77. In new code, programmers should consider the use - of the *note GET_ENVIRONMENT_VARIABLE:: intrinsic defined by the - Fortran 2003 standard. - - Note that 'GETENV' need not be thread-safe. It is the - responsibility of the user to ensure that the environment is not - being updated concurrently with a call to the 'GETENV' intrinsic. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL GETENV(NAME, VALUE)' - -_Arguments_: - NAME Shall be of type 'CHARACTER' and of default - kind. - VALUE Shall be of type 'CHARACTER' and of default - kind. - -_Return value_: - Stores the value of NAME in VALUE. If VALUE is not large enough to - hold the data, it is truncated. If NAME is not set, VALUE will be - filled with blanks. - -_Example_: - PROGRAM test_getenv - CHARACTER(len=255) :: homedir - CALL getenv("HOME", homedir) - WRITE (*,*) TRIM(homedir) - END PROGRAM - -_See also_: - *note GET_ENVIRONMENT_VARIABLE:: - - -File: gfortran.info, Node: GET_ENVIRONMENT_VARIABLE, Next: GETGID, Prev: GETENV, Up: Intrinsic Procedures - -8.103 'GET_ENVIRONMENT_VARIABLE' -- Get an environmental variable -================================================================= - -_Description_: - Get the VALUE of the environmental variable NAME. - - Note that 'GET_ENVIRONMENT_VARIABLE' need not be thread-safe. It - is the responsibility of the user to ensure that the environment is - not being updated concurrently with a call to the - 'GET_ENVIRONMENT_VARIABLE' intrinsic. - -_Standard_: - Fortran 2003 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL GET_ENVIRONMENT_VARIABLE(NAME[, VALUE, LENGTH, STATUS, - TRIM_NAME)' - -_Arguments_: - NAME Shall be a scalar of type 'CHARACTER' and of - default kind. - VALUE (Optional) Shall be a scalar of type 'CHARACTER' - and of default kind. - LENGTH (Optional) Shall be a scalar of type 'INTEGER' - and of default kind. - STATUS (Optional) Shall be a scalar of type 'INTEGER' - and of default kind. - TRIM_NAME (Optional) Shall be a scalar of type 'LOGICAL' - and of default kind. - -_Return value_: - Stores the value of NAME in VALUE. If VALUE is not large enough to - hold the data, it is truncated. If NAME is not set, VALUE will be - filled with blanks. Argument LENGTH contains the length needed for - storing the environment variable NAME or zero if it is not present. - STATUS is -1 if VALUE is present but too short for the environment - variable; it is 1 if the environment variable does not exist and 2 - if the processor does not support environment variables; in all - other cases STATUS is zero. If TRIM_NAME is present with the value - '.FALSE.', the trailing blanks in NAME are significant; otherwise - they are not part of the environment variable name. - -_Example_: - PROGRAM test_getenv - CHARACTER(len=255) :: homedir - CALL get_environment_variable("HOME", homedir) - WRITE (*,*) TRIM(homedir) - END PROGRAM - - -File: gfortran.info, Node: GETGID, Next: GETLOG, Prev: GET_ENVIRONMENT_VARIABLE, Up: Intrinsic Procedures - -8.104 'GETGID' -- Group ID function -=================================== - -_Description_: - Returns the numerical group ID of the current process. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = GETGID()' - -_Return value_: - The return value of 'GETGID' is an 'INTEGER' of the default kind. - -_Example_: - See 'GETPID' for an example. - -_See also_: - *note GETPID::, *note GETUID:: - - -File: gfortran.info, Node: GETLOG, Next: GETPID, Prev: GETGID, Up: Intrinsic Procedures - -8.105 'GETLOG' -- Get login name -================================ - -_Description_: - Gets the username under which the program is running. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL GETLOG(C)' - -_Arguments_: - C Shall be of type 'CHARACTER' and of default - kind. - -_Return value_: - Stores the current user name in LOGIN. (On systems where POSIX - functions 'geteuid' and 'getpwuid' are not available, and the - 'getlogin' function is not implemented either, this will return a - blank string.) - -_Example_: - PROGRAM TEST_GETLOG - CHARACTER(32) :: login - CALL GETLOG(login) - WRITE(*,*) login - END PROGRAM - -_See also_: - *note GETUID:: - - -File: gfortran.info, Node: GETPID, Next: GETUID, Prev: GETLOG, Up: Intrinsic Procedures - -8.106 'GETPID' -- Process ID function -===================================== - -_Description_: - Returns the numerical process identifier of the current process. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = GETPID()' - -_Return value_: - The return value of 'GETPID' is an 'INTEGER' of the default kind. - -_Example_: - program info - print *, "The current process ID is ", getpid() - print *, "Your numerical user ID is ", getuid() - print *, "Your numerical group ID is ", getgid() - end program info - -_See also_: - *note GETGID::, *note GETUID:: - - -File: gfortran.info, Node: GETUID, Next: GMTIME, Prev: GETPID, Up: Intrinsic Procedures - -8.107 'GETUID' -- User ID function -================================== - -_Description_: - Returns the numerical user ID of the current process. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = GETUID()' - -_Return value_: - The return value of 'GETUID' is an 'INTEGER' of the default kind. - -_Example_: - See 'GETPID' for an example. - -_See also_: - *note GETPID::, *note GETLOG:: - - -File: gfortran.info, Node: GMTIME, Next: HOSTNM, Prev: GETUID, Up: Intrinsic Procedures - -8.108 'GMTIME' -- Convert time to GMT info -========================================== - -_Description_: - Given a system time value TIME (as provided by the 'TIME8' - intrinsic), fills VALUES with values extracted from it appropriate - to the UTC time zone (Universal Coordinated Time, also known in - some countries as GMT, Greenwich Mean Time), using 'gmtime(3)'. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL GMTIME(TIME, VALUES)' - -_Arguments_: - TIME An 'INTEGER' scalar expression corresponding to - a system time, with 'INTENT(IN)'. - VALUES A default 'INTEGER' array with 9 elements, with - 'INTENT(OUT)'. - -_Return value_: - The elements of VALUES are assigned as follows: - 1. Seconds after the minute, range 0-59 or 0-61 to allow for leap - seconds - 2. Minutes after the hour, range 0-59 - 3. Hours past midnight, range 0-23 - 4. Day of month, range 0-31 - 5. Number of months since January, range 0-12 - 6. Years since 1900 - 7. Number of days since Sunday, range 0-6 - 8. Days since January 1 - 9. Daylight savings indicator: positive if daylight savings is in - effect, zero if not, and negative if the information is not - available. - -_See also_: - *note CTIME::, *note LTIME::, *note TIME::, *note TIME8:: - - -File: gfortran.info, Node: HOSTNM, Next: HUGE, Prev: GMTIME, Up: Intrinsic Procedures - -8.109 'HOSTNM' -- Get system host name -====================================== - -_Description_: - Retrieves the host name of the system on which the program is - running. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL HOSTNM(C [, STATUS])' - 'STATUS = HOSTNM(NAME)' - -_Arguments_: - C Shall of type 'CHARACTER' and of default kind. - STATUS (Optional) status flag of type 'INTEGER'. - Returns 0 on success, or a system specific error - code otherwise. - -_Return value_: - In either syntax, NAME is set to the current hostname if it can be - obtained, or to a blank string otherwise. - - -File: gfortran.info, Node: HUGE, Next: HYPOT, Prev: HOSTNM, Up: Intrinsic Procedures - -8.110 'HUGE' -- Largest number of a kind -======================================== - -_Description_: - 'HUGE(X)' returns the largest number that is not an infinity in the - model of the type of 'X'. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = HUGE(X)' - -_Arguments_: - X Shall be of type 'REAL' or 'INTEGER'. - -_Return value_: - The return value is of the same type and kind as X - -_Example_: - program test_huge_tiny - print *, huge(0), huge(0.0), huge(0.0d0) - print *, tiny(0.0), tiny(0.0d0) - end program test_huge_tiny - - -File: gfortran.info, Node: HYPOT, Next: IACHAR, Prev: HUGE, Up: Intrinsic Procedures - -8.111 'HYPOT' -- Euclidean distance function -============================================ - -_Description_: - 'HYPOT(X,Y)' is the Euclidean distance function. It is equal to - \sqrt{X^2 + Y^2}, without undue underflow or overflow. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = HYPOT(X, Y)' - -_Arguments_: - X The type shall be 'REAL'. - Y The type and kind type parameter shall be the - same as X. - -_Return value_: - The return value has the same type and kind type parameter as X. - -_Example_: - program test_hypot - real(4) :: x = 1.e0_4, y = 0.5e0_4 - x = hypot(x,y) - end program test_hypot - - -File: gfortran.info, Node: IACHAR, Next: IALL, Prev: HYPOT, Up: Intrinsic Procedures - -8.112 'IACHAR' -- Code in ASCII collating sequence -================================================== - -_Description_: - 'IACHAR(C)' returns the code for the ASCII character in the first - character position of 'C'. - -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = IACHAR(C [, KIND])' - -_Arguments_: - C Shall be a scalar 'CHARACTER', with 'INTENT(IN)' - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. - -_Example_: - program test_iachar - integer i - i = iachar(' ') - end program test_iachar - -_Note_: - See *note ICHAR:: for a discussion of converting between numerical - values and formatted string representations. - -_See also_: - *note ACHAR::, *note CHAR::, *note ICHAR:: - - -File: gfortran.info, Node: IALL, Next: IAND, Prev: IACHAR, Up: Intrinsic Procedures - -8.113 'IALL' -- Bitwise AND of array elements -============================================= - -_Description_: - Reduces with bitwise AND the elements of ARRAY along dimension DIM - if the corresponding element in MASK is 'TRUE'. - -_Standard_: - Fortran 2008 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = IALL(ARRAY[, MASK])' - 'RESULT = IALL(ARRAY, DIM[, MASK])' - -_Arguments_: - ARRAY Shall be an array of type 'INTEGER' - DIM (Optional) shall be a scalar of type 'INTEGER' - with a value in the range from 1 to n, where n - equals the rank of ARRAY. - MASK (Optional) shall be of type 'LOGICAL' and either - be a scalar or an array of the same shape as - ARRAY. - -_Return value_: - The result is of the same type as ARRAY. - - If DIM is absent, a scalar with the bitwise ALL of all elements in - ARRAY is returned. Otherwise, an array of rank n-1, where n equals - the rank of ARRAY, and a shape similar to that of ARRAY with - dimension DIM dropped is returned. - -_Example_: - PROGRAM test_iall - INTEGER(1) :: a(2) - - a(1) = b'00100100' - a(2) = b'01101010' - - ! prints 00100000 - PRINT '(b8.8)', IALL(a) - END PROGRAM - -_See also_: - *note IANY::, *note IPARITY::, *note IAND:: - - -File: gfortran.info, Node: IAND, Next: IANY, Prev: IALL, Up: Intrinsic Procedures - -8.114 'IAND' -- Bitwise logical and -=================================== - -_Description_: - Bitwise logical 'AND'. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = IAND(I, J)' - -_Arguments_: - I The type shall be 'INTEGER'. - J The type shall be 'INTEGER', of the same kind as - I. (As a GNU extension, different kinds are - also permitted.) - -_Return value_: - The return type is 'INTEGER', of the same kind as the arguments. - (If the argument kinds differ, it is of the same kind as the larger - argument.) - -_Example_: - PROGRAM test_iand - INTEGER :: a, b - DATA a / Z'F' /, b / Z'3' / - WRITE (*,*) IAND(a, b) - END PROGRAM - -_See also_: - *note IOR::, *note IEOR::, *note IBITS::, *note IBSET::, *note - IBCLR::, *note NOT:: - - -File: gfortran.info, Node: IANY, Next: IARGC, Prev: IAND, Up: Intrinsic Procedures - -8.115 'IANY' -- Bitwise OR of array elements -============================================ - -_Description_: - Reduces with bitwise OR (inclusive or) the elements of ARRAY along - dimension DIM if the corresponding element in MASK is 'TRUE'. - -_Standard_: - Fortran 2008 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = IANY(ARRAY[, MASK])' - 'RESULT = IANY(ARRAY, DIM[, MASK])' - -_Arguments_: - ARRAY Shall be an array of type 'INTEGER' - DIM (Optional) shall be a scalar of type 'INTEGER' - with a value in the range from 1 to n, where n - equals the rank of ARRAY. - MASK (Optional) shall be of type 'LOGICAL' and either - be a scalar or an array of the same shape as - ARRAY. - -_Return value_: - The result is of the same type as ARRAY. - - If DIM is absent, a scalar with the bitwise OR of all elements in - ARRAY is returned. Otherwise, an array of rank n-1, where n equals - the rank of ARRAY, and a shape similar to that of ARRAY with - dimension DIM dropped is returned. - -_Example_: - PROGRAM test_iany - INTEGER(1) :: a(2) - - a(1) = b'00100100' - a(2) = b'01101010' - - ! prints 01101110 - PRINT '(b8.8)', IANY(a) - END PROGRAM - -_See also_: - *note IPARITY::, *note IALL::, *note IOR:: - - -File: gfortran.info, Node: IARGC, Next: IBCLR, Prev: IANY, Up: Intrinsic Procedures - -8.116 'IARGC' -- Get the number of command line arguments -========================================================= - -_Description_: - 'IARGC' returns the number of arguments passed on the command line - when the containing program was invoked. - - This intrinsic routine is provided for backwards compatibility with - GNU Fortran 77. In new code, programmers should consider the use - of the *note COMMAND_ARGUMENT_COUNT:: intrinsic defined by the - Fortran 2003 standard. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = IARGC()' - -_Arguments_: - None. - -_Return value_: - The number of command line arguments, type 'INTEGER(4)'. - -_Example_: - See *note GETARG:: - -_See also_: - GNU Fortran 77 compatibility subroutine: *note GETARG:: - - Fortran 2003 functions and subroutines: *note GET_COMMAND::, *note - GET_COMMAND_ARGUMENT::, *note COMMAND_ARGUMENT_COUNT:: - - -File: gfortran.info, Node: IBCLR, Next: IBITS, Prev: IARGC, Up: Intrinsic Procedures - -8.117 'IBCLR' -- Clear bit -========================== - -_Description_: - 'IBCLR' returns the value of I with the bit at position POS set to - zero. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = IBCLR(I, POS)' - -_Arguments_: - I The type shall be 'INTEGER'. - POS The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note IBITS::, *note IBSET::, *note IAND::, *note IOR::, *note - IEOR::, *note MVBITS:: - - -File: gfortran.info, Node: IBITS, Next: IBSET, Prev: IBCLR, Up: Intrinsic Procedures - -8.118 'IBITS' -- Bit extraction -=============================== - -_Description_: - 'IBITS' extracts a field of length LEN from I, starting from bit - position POS and extending left for LEN bits. The result is - right-justified and the remaining bits are zeroed. The value of - 'POS+LEN' must be less than or equal to the value 'BIT_SIZE(I)'. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = IBITS(I, POS, LEN)' - -_Arguments_: - I The type shall be 'INTEGER'. - POS The type shall be 'INTEGER'. - LEN The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note BIT_SIZE::, *note IBCLR::, *note IBSET::, *note IAND::, *note - IOR::, *note IEOR:: - - -File: gfortran.info, Node: IBSET, Next: ICHAR, Prev: IBITS, Up: Intrinsic Procedures - -8.119 'IBSET' -- Set bit -======================== - -_Description_: - 'IBSET' returns the value of I with the bit at position POS set to - one. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = IBSET(I, POS)' - -_Arguments_: - I The type shall be 'INTEGER'. - POS The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note IBCLR::, *note IBITS::, *note IAND::, *note IOR::, *note - IEOR::, *note MVBITS:: - - -File: gfortran.info, Node: ICHAR, Next: IDATE, Prev: IBSET, Up: Intrinsic Procedures - -8.120 'ICHAR' -- Character-to-integer conversion function -========================================================= - -_Description_: - 'ICHAR(C)' returns the code for the character in the first - character position of 'C' in the system's native character set. - The correspondence between characters and their codes is not - necessarily the same across different GNU Fortran implementations. - -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ICHAR(C [, KIND])' - -_Arguments_: - C Shall be a scalar 'CHARACTER', with 'INTENT(IN)' - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. - -_Example_: - program test_ichar - integer i - i = ichar(' ') - end program test_ichar - -_Specific names_: - Name Argument Return type Standard - 'ICHAR(C)' 'CHARACTER 'INTEGER(4)' Fortran 77 and - C' later - -_Note_: - No intrinsic exists to convert between a numeric value and a - formatted character string representation - for instance, given the - 'CHARACTER' value ''154'', obtaining an 'INTEGER' or 'REAL' value - with the value 154, or vice versa. Instead, this functionality is - provided by internal-file I/O, as in the following example: - program read_val - integer value - character(len=10) string, string2 - string = '154' - - ! Convert a string to a numeric value - read (string,'(I10)') value - print *, value - - ! Convert a value to a formatted string - write (string2,'(I10)') value - print *, string2 - end program read_val - -_See also_: - *note ACHAR::, *note CHAR::, *note IACHAR:: - - -File: gfortran.info, Node: IDATE, Next: IEOR, Prev: ICHAR, Up: Intrinsic Procedures - -8.121 'IDATE' -- Get current local time subroutine (day/month/year) -=================================================================== - -_Description_: - 'IDATE(VALUES)' Fills VALUES with the numerical values at the - current local time. The day (in the range 1-31), month (in the - range 1-12), and year appear in elements 1, 2, and 3 of VALUES, - respectively. The year has four significant digits. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL IDATE(VALUES)' - -_Arguments_: - VALUES The type shall be 'INTEGER, DIMENSION(3)' and - the kind shall be the default integer kind. - -_Return value_: - Does not return anything. - -_Example_: - program test_idate - integer, dimension(3) :: tarray - call idate(tarray) - print *, tarray(1) - print *, tarray(2) - print *, tarray(3) - end program test_idate - - -File: gfortran.info, Node: IEOR, Next: IERRNO, Prev: IDATE, Up: Intrinsic Procedures - -8.122 'IEOR' -- Bitwise logical exclusive or -============================================ - -_Description_: - 'IEOR' returns the bitwise Boolean exclusive-OR of I and J. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = IEOR(I, J)' - -_Arguments_: - I The type shall be 'INTEGER'. - J The type shall be 'INTEGER', of the same kind as - I. (As a GNU extension, different kinds are - also permitted.) - -_Return value_: - The return type is 'INTEGER', of the same kind as the arguments. - (If the argument kinds differ, it is of the same kind as the larger - argument.) - -_See also_: - *note IOR::, *note IAND::, *note IBITS::, *note IBSET::, *note - IBCLR::, *note NOT:: - - -File: gfortran.info, Node: IERRNO, Next: IMAGE_INDEX, Prev: IEOR, Up: Intrinsic Procedures - -8.123 'IERRNO' -- Get the last system error number -================================================== - -_Description_: - Returns the last system error number, as given by the C 'errno' - variable. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = IERRNO()' - -_Arguments_: - None. - -_Return value_: - The return value is of type 'INTEGER' and of the default integer - kind. - -_See also_: - *note PERROR:: - - -File: gfortran.info, Node: IMAGE_INDEX, Next: INDEX intrinsic, Prev: IERRNO, Up: Intrinsic Procedures - -8.124 'IMAGE_INDEX' -- Function that converts a cosubscript to an image index -============================================================================= - -_Description_: - Returns the image index belonging to a cosubscript. - -_Standard_: - Fortran 2008 and later - -_Class_: - Inquiry function. - -_Syntax_: - 'RESULT = IMAGE_INDEX(COARRAY, SUB)' - -_Arguments_: None. - COARRAY Coarray of any type. - SUB default integer rank-1 array of a size equal to - the corank of COARRAY. - -_Return value_: - Scalar default integer with the value of the image index which - corresponds to the cosubscripts. For invalid cosubscripts the - result is zero. - -_Example_: - INTEGER :: array[2,-1:4,8,*] - ! Writes 28 (or 0 if there are fewer than 28 images) - WRITE (*,*) IMAGE_INDEX (array, [2,0,3,1]) - -_See also_: - *note THIS_IMAGE::, *note NUM_IMAGES:: - - -File: gfortran.info, Node: INDEX intrinsic, Next: INT, Prev: IMAGE_INDEX, Up: Intrinsic Procedures - -8.125 'INDEX' -- Position of a substring within a string -======================================================== - -_Description_: - Returns the position of the start of the first occurrence of string - SUBSTRING as a substring in STRING, counting from one. If - SUBSTRING is not present in STRING, zero is returned. If the BACK - argument is present and true, the return value is the start of the - last occurrence rather than the first. - -_Standard_: - Fortran 77 and later, with KIND argument Fortran 2003 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = INDEX(STRING, SUBSTRING [, BACK [, KIND]])' - -_Arguments_: - STRING Shall be a scalar 'CHARACTER', with 'INTENT(IN)' - SUBSTRING Shall be a scalar 'CHARACTER', with 'INTENT(IN)' - BACK (Optional) Shall be a scalar 'LOGICAL', with - 'INTENT(IN)' - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. - -_Specific names_: - Name Argument Return type Standard - 'INDEX(STRING, 'CHARACTER' 'INTEGER(4)' Fortran 77 and - SUBSTRING)' later - -_See also_: - *note SCAN::, *note VERIFY:: - - -File: gfortran.info, Node: INT, Next: INT2, Prev: INDEX intrinsic, Up: Intrinsic Procedures - -8.126 'INT' -- Convert to integer type -====================================== - -_Description_: - Convert to integer type - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = INT(A [, KIND))' - -_Arguments_: - A Shall be of type 'INTEGER', 'REAL', or - 'COMPLEX'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - These functions return a 'INTEGER' variable or array under the - following rules: - - (A) - If A is of type 'INTEGER', 'INT(A) = A' - (B) - If A is of type 'REAL' and |A| < 1, 'INT(A)' equals '0'. If - |A| \geq 1, then 'INT(A)' equals the largest integer that does - not exceed the range of A and whose sign is the same as the - sign of A. - (C) - If A is of type 'COMPLEX', rule B is applied to the real part - of A. - -_Example_: - program test_int - integer :: i = 42 - complex :: z = (-3.7, 1.0) - print *, int(i) - print *, int(z), int(z,8) - end program - -_Specific names_: - Name Argument Return type Standard - 'INT(A)' 'REAL(4) A' 'INTEGER' Fortran 77 and - later - 'IFIX(A)' 'REAL(4) A' 'INTEGER' Fortran 77 and - later - 'IDINT(A)' 'REAL(8) A' 'INTEGER' Fortran 77 and - later - - -File: gfortran.info, Node: INT2, Next: INT8, Prev: INT, Up: Intrinsic Procedures - -8.127 'INT2' -- Convert to 16-bit integer type -============================================== - -_Description_: - Convert to a 'KIND=2' integer type. This is equivalent to the - standard 'INT' intrinsic with an optional argument of 'KIND=2', and - is only included for backwards compatibility. - - The 'SHORT' intrinsic is equivalent to 'INT2'. - -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = INT2(A)' - -_Arguments_: - A Shall be of type 'INTEGER', 'REAL', or - 'COMPLEX'. - -_Return value_: - The return value is a 'INTEGER(2)' variable. - -_See also_: - *note INT::, *note INT8::, *note LONG:: - - -File: gfortran.info, Node: INT8, Next: IOR, Prev: INT2, Up: Intrinsic Procedures - -8.128 'INT8' -- Convert to 64-bit integer type -============================================== - -_Description_: - Convert to a 'KIND=8' integer type. This is equivalent to the - standard 'INT' intrinsic with an optional argument of 'KIND=8', and - is only included for backwards compatibility. - -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = INT8(A)' - -_Arguments_: - A Shall be of type 'INTEGER', 'REAL', or - 'COMPLEX'. - -_Return value_: - The return value is a 'INTEGER(8)' variable. - -_See also_: - *note INT::, *note INT2::, *note LONG:: - - -File: gfortran.info, Node: IOR, Next: IPARITY, Prev: INT8, Up: Intrinsic Procedures - -8.129 'IOR' -- Bitwise logical or -================================= - -_Description_: - 'IOR' returns the bitwise Boolean inclusive-OR of I and J. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = IOR(I, J)' - -_Arguments_: - I The type shall be 'INTEGER'. - J The type shall be 'INTEGER', of the same kind as - I. (As a GNU extension, different kinds are - also permitted.) - -_Return value_: - The return type is 'INTEGER', of the same kind as the arguments. - (If the argument kinds differ, it is of the same kind as the larger - argument.) - -_See also_: - *note IEOR::, *note IAND::, *note IBITS::, *note IBSET::, *note - IBCLR::, *note NOT:: - - -File: gfortran.info, Node: IPARITY, Next: IRAND, Prev: IOR, Up: Intrinsic Procedures - -8.130 'IPARITY' -- Bitwise XOR of array elements -================================================ - -_Description_: - Reduces with bitwise XOR (exclusive or) the elements of ARRAY along - dimension DIM if the corresponding element in MASK is 'TRUE'. - -_Standard_: - Fortran 2008 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = IPARITY(ARRAY[, MASK])' - 'RESULT = IPARITY(ARRAY, DIM[, MASK])' - -_Arguments_: - ARRAY Shall be an array of type 'INTEGER' - DIM (Optional) shall be a scalar of type 'INTEGER' - with a value in the range from 1 to n, where n - equals the rank of ARRAY. - MASK (Optional) shall be of type 'LOGICAL' and either - be a scalar or an array of the same shape as - ARRAY. - -_Return value_: - The result is of the same type as ARRAY. - - If DIM is absent, a scalar with the bitwise XOR of all elements in - ARRAY is returned. Otherwise, an array of rank n-1, where n equals - the rank of ARRAY, and a shape similar to that of ARRAY with - dimension DIM dropped is returned. - -_Example_: - PROGRAM test_iparity - INTEGER(1) :: a(2) - - a(1) = b'00100100' - a(2) = b'01101010' - - ! prints 01001110 - PRINT '(b8.8)', IPARITY(a) - END PROGRAM - -_See also_: - *note IANY::, *note IALL::, *note IEOR::, *note PARITY:: - - -File: gfortran.info, Node: IRAND, Next: IS_IOSTAT_END, Prev: IPARITY, Up: Intrinsic Procedures - -8.131 'IRAND' -- Integer pseudo-random number -============================================= - -_Description_: - 'IRAND(FLAG)' returns a pseudo-random number from a uniform - distribution between 0 and a system-dependent limit (which is in - most cases 2147483647). If FLAG is 0, the next number in the - current sequence is returned; if FLAG is 1, the generator is - restarted by 'CALL SRAND(0)'; if FLAG has any other value, it is - used as a new seed with 'SRAND'. - - This intrinsic routine is provided for backwards compatibility with - GNU Fortran 77. It implements a simple modulo generator as - provided by 'g77'. For new code, one should consider the use of - *note RANDOM_NUMBER:: as it implements a superior algorithm. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = IRAND(I)' - -_Arguments_: - I Shall be a scalar 'INTEGER' of kind 4. - -_Return value_: - The return value is of 'INTEGER(kind=4)' type. - -_Example_: - program test_irand - integer,parameter :: seed = 86456 - - call srand(seed) - print *, irand(), irand(), irand(), irand() - print *, irand(seed), irand(), irand(), irand() - end program test_irand - - -File: gfortran.info, Node: IS_IOSTAT_END, Next: IS_IOSTAT_EOR, Prev: IRAND, Up: Intrinsic Procedures - -8.132 'IS_IOSTAT_END' -- Test for end-of-file value -=================================================== - -_Description_: - 'IS_IOSTAT_END' tests whether an variable has the value of the I/O - status "end of file". The function is equivalent to comparing the - variable with the 'IOSTAT_END' parameter of the intrinsic module - 'ISO_FORTRAN_ENV'. - -_Standard_: - Fortran 2003 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = IS_IOSTAT_END(I)' - -_Arguments_: - I Shall be of the type 'INTEGER'. - -_Return value_: - Returns a 'LOGICAL' of the default kind, which '.TRUE.' if I has - the value which indicates an end of file condition for 'IOSTAT=' - specifiers, and is '.FALSE.' otherwise. - -_Example_: - PROGRAM iostat - IMPLICIT NONE - INTEGER :: stat, i - OPEN(88, FILE='test.dat') - READ(88, *, IOSTAT=stat) i - IF(IS_IOSTAT_END(stat)) STOP 'END OF FILE' - END PROGRAM - - -File: gfortran.info, Node: IS_IOSTAT_EOR, Next: ISATTY, Prev: IS_IOSTAT_END, Up: Intrinsic Procedures - -8.133 'IS_IOSTAT_EOR' -- Test for end-of-record value -===================================================== - -_Description_: - 'IS_IOSTAT_EOR' tests whether an variable has the value of the I/O - status "end of record". The function is equivalent to comparing - the variable with the 'IOSTAT_EOR' parameter of the intrinsic - module 'ISO_FORTRAN_ENV'. - -_Standard_: - Fortran 2003 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = IS_IOSTAT_EOR(I)' - -_Arguments_: - I Shall be of the type 'INTEGER'. - -_Return value_: - Returns a 'LOGICAL' of the default kind, which '.TRUE.' if I has - the value which indicates an end of file condition for 'IOSTAT=' - specifiers, and is '.FALSE.' otherwise. - -_Example_: - PROGRAM iostat - IMPLICIT NONE - INTEGER :: stat, i(50) - OPEN(88, FILE='test.dat', FORM='UNFORMATTED') - READ(88, IOSTAT=stat) i - IF(IS_IOSTAT_EOR(stat)) STOP 'END OF RECORD' - END PROGRAM - - -File: gfortran.info, Node: ISATTY, Next: ISHFT, Prev: IS_IOSTAT_EOR, Up: Intrinsic Procedures - -8.134 'ISATTY' -- Whether a unit is a terminal device. -====================================================== - -_Description_: - Determine whether a unit is connected to a terminal device. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = ISATTY(UNIT)' - -_Arguments_: - UNIT Shall be a scalar 'INTEGER'. - -_Return value_: - Returns '.TRUE.' if the UNIT is connected to a terminal device, - '.FALSE.' otherwise. - -_Example_: - PROGRAM test_isatty - INTEGER(kind=1) :: unit - DO unit = 1, 10 - write(*,*) isatty(unit=unit) - END DO - END PROGRAM -_See also_: - *note TTYNAM:: - - -File: gfortran.info, Node: ISHFT, Next: ISHFTC, Prev: ISATTY, Up: Intrinsic Procedures - -8.135 'ISHFT' -- Shift bits -=========================== - -_Description_: - 'ISHFT' returns a value corresponding to I with all of the bits - shifted SHIFT places. A value of SHIFT greater than zero - corresponds to a left shift, a value of zero corresponds to no - shift, and a value less than zero corresponds to a right shift. If - the absolute value of SHIFT is greater than 'BIT_SIZE(I)', the - value is undefined. Bits shifted out from the left end or right - end are lost; zeros are shifted in from the opposite end. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ISHFT(I, SHIFT)' - -_Arguments_: - I The type shall be 'INTEGER'. - SHIFT The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note ISHFTC:: - - -File: gfortran.info, Node: ISHFTC, Next: ISNAN, Prev: ISHFT, Up: Intrinsic Procedures - -8.136 'ISHFTC' -- Shift bits circularly -======================================= - -_Description_: - 'ISHFTC' returns a value corresponding to I with the rightmost SIZE - bits shifted circularly SHIFT places; that is, bits shifted out one - end are shifted into the opposite end. A value of SHIFT greater - than zero corresponds to a left shift, a value of zero corresponds - to no shift, and a value less than zero corresponds to a right - shift. The absolute value of SHIFT must be less than SIZE. If the - SIZE argument is omitted, it is taken to be equivalent to - 'BIT_SIZE(I)'. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = ISHFTC(I, SHIFT [, SIZE])' - -_Arguments_: - I The type shall be 'INTEGER'. - SHIFT The type shall be 'INTEGER'. - SIZE (Optional) The type shall be 'INTEGER'; the - value must be greater than zero and less than or - equal to 'BIT_SIZE(I)'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note ISHFT:: - - -File: gfortran.info, Node: ISNAN, Next: ITIME, Prev: ISHFTC, Up: Intrinsic Procedures - -8.137 'ISNAN' -- Test for a NaN -=============================== - -_Description_: - 'ISNAN' tests whether a floating-point value is an IEEE - Not-a-Number (NaN). -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'ISNAN(X)' - -_Arguments_: - X Variable of the type 'REAL'. - - -_Return value_: - Returns a default-kind 'LOGICAL'. The returned value is 'TRUE' if - X is a NaN and 'FALSE' otherwise. - -_Example_: - program test_nan - implicit none - real :: x - x = -1.0 - x = sqrt(x) - if (isnan(x)) stop '"x" is a NaN' - end program test_nan - - -File: gfortran.info, Node: ITIME, Next: KILL, Prev: ISNAN, Up: Intrinsic Procedures - -8.138 'ITIME' -- Get current local time subroutine (hour/minutes/seconds) -========================================================================= - -_Description_: - 'IDATE(VALUES)' Fills VALUES with the numerical values at the - current local time. The hour (in the range 1-24), minute (in the - range 1-60), and seconds (in the range 1-60) appear in elements 1, - 2, and 3 of VALUES, respectively. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL ITIME(VALUES)' - -_Arguments_: - VALUES The type shall be 'INTEGER, DIMENSION(3)' and - the kind shall be the default integer kind. - -_Return value_: - Does not return anything. - -_Example_: - program test_itime - integer, dimension(3) :: tarray - call itime(tarray) - print *, tarray(1) - print *, tarray(2) - print *, tarray(3) - end program test_itime - - -File: gfortran.info, Node: KILL, Next: KIND, Prev: ITIME, Up: Intrinsic Procedures - -8.139 'KILL' -- Send a signal to a process -========================================== - -_Description_: -_Standard_: - Sends the signal specified by SIGNAL to the process PID. See - 'kill(2)'. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL KILL(C, VALUE [, STATUS])' - 'STATUS = KILL(C, VALUE)' - -_Arguments_: - C Shall be a scalar 'INTEGER', with 'INTENT(IN)' - VALUE Shall be a scalar 'INTEGER', with 'INTENT(IN)' - STATUS (Optional) status flag of type 'INTEGER(4)' or - 'INTEGER(8)'. Returns 0 on success, or a - system-specific error code otherwise. - -_See also_: - *note ABORT::, *note EXIT:: - - -File: gfortran.info, Node: KIND, Next: LBOUND, Prev: KILL, Up: Intrinsic Procedures - -8.140 'KIND' -- Kind of an entity -================================= - -_Description_: - 'KIND(X)' returns the kind value of the entity X. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'K = KIND(X)' - -_Arguments_: - X Shall be of type 'LOGICAL', 'INTEGER', 'REAL', - 'COMPLEX' or 'CHARACTER'. - -_Return value_: - The return value is a scalar of type 'INTEGER' and of the default - integer kind. - -_Example_: - program test_kind - integer,parameter :: kc = kind(' ') - integer,parameter :: kl = kind(.true.) - - print *, "The default character kind is ", kc - print *, "The default logical kind is ", kl - end program test_kind - - -File: gfortran.info, Node: LBOUND, Next: LCOBOUND, Prev: KIND, Up: Intrinsic Procedures - -8.141 'LBOUND' -- Lower dimension bounds of an array -==================================================== - -_Description_: - Returns the lower bounds of an array, or a single lower bound along - the DIM dimension. -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = LBOUND(ARRAY [, DIM [, KIND]])' - -_Arguments_: - ARRAY Shall be an array, of any type. - DIM (Optional) Shall be a scalar 'INTEGER'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. If DIM is - absent, the result is an array of the lower bounds of ARRAY. If - DIM is present, the result is a scalar corresponding to the lower - bound of the array along that dimension. If ARRAY is an expression - rather than a whole array or array structure component, or if it - has a zero extent along the relevant dimension, the lower bound is - taken to be 1. - -_See also_: - *note UBOUND::, *note LCOBOUND:: - - -File: gfortran.info, Node: LCOBOUND, Next: LEADZ, Prev: LBOUND, Up: Intrinsic Procedures - -8.142 'LCOBOUND' -- Lower codimension bounds of an array -======================================================== - -_Description_: - Returns the lower bounds of a coarray, or a single lower cobound - along the DIM codimension. -_Standard_: - Fortran 2008 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = LCOBOUND(COARRAY [, DIM [, KIND]])' - -_Arguments_: - ARRAY Shall be an coarray, of any type. - DIM (Optional) Shall be a scalar 'INTEGER'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. If DIM is - absent, the result is an array of the lower cobounds of COARRAY. - If DIM is present, the result is a scalar corresponding to the - lower cobound of the array along that codimension. - -_See also_: - *note UCOBOUND::, *note LBOUND:: - - -File: gfortran.info, Node: LEADZ, Next: LEN, Prev: LCOBOUND, Up: Intrinsic Procedures - -8.143 'LEADZ' -- Number of leading zero bits of an integer -========================================================== - -_Description_: - 'LEADZ' returns the number of leading zero bits of an integer. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LEADZ(I)' - -_Arguments_: - I Shall be of type 'INTEGER'. - -_Return value_: - The type of the return value is the default 'INTEGER'. If all the - bits of 'I' are zero, the result value is 'BIT_SIZE(I)'. - -_Example_: - PROGRAM test_leadz - WRITE (*,*) BIT_SIZE(1) ! prints 32 - WRITE (*,*) LEADZ(1) ! prints 31 - END PROGRAM - -_See also_: - *note BIT_SIZE::, *note TRAILZ::, *note POPCNT::, *note POPPAR:: - - -File: gfortran.info, Node: LEN, Next: LEN_TRIM, Prev: LEADZ, Up: Intrinsic Procedures - -8.144 'LEN' -- Length of a character entity -=========================================== - -_Description_: - Returns the length of a character string. If STRING is an array, - the length of an element of STRING is returned. Note that STRING - need not be defined when this intrinsic is invoked, since only the - length, not the content, of STRING is needed. - -_Standard_: - Fortran 77 and later, with KIND argument Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'L = LEN(STRING [, KIND])' - -_Arguments_: - STRING Shall be a scalar or array of type 'CHARACTER', - with 'INTENT(IN)' - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. - -_Specific names_: - Name Argument Return type Standard - 'LEN(STRING)' 'CHARACTER' 'INTEGER' Fortran 77 and - later - -_See also_: - *note LEN_TRIM::, *note ADJUSTL::, *note ADJUSTR:: - - -File: gfortran.info, Node: LEN_TRIM, Next: LGE, Prev: LEN, Up: Intrinsic Procedures - -8.145 'LEN_TRIM' -- Length of a character entity without trailing blank characters -================================================================================== - -_Description_: - Returns the length of a character string, ignoring any trailing - blanks. - -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LEN_TRIM(STRING [, KIND])' - -_Arguments_: - STRING Shall be a scalar of type 'CHARACTER', with - 'INTENT(IN)' - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. - -_See also_: - *note LEN::, *note ADJUSTL::, *note ADJUSTR:: - - -File: gfortran.info, Node: LGE, Next: LGT, Prev: LEN_TRIM, Up: Intrinsic Procedures - -8.146 'LGE' -- Lexical greater than or equal -============================================ - -_Description_: - Determines whether one string is lexically greater than or equal to - another string, where the two strings are interpreted as containing - ASCII character codes. If the String A and String B are not the - same length, the shorter is compared as if spaces were appended to - it to form a value that has the same length as the longer. - - In general, the lexical comparison intrinsics 'LGE', 'LGT', 'LLE', - and 'LLT' differ from the corresponding intrinsic operators '.GE.', - '.GT.', '.LE.', and '.LT.', in that the latter use the processor's - character ordering (which is not ASCII on some targets), whereas - the former always use the ASCII ordering. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LGE(STRING_A, STRING_B)' - -_Arguments_: - STRING_A Shall be of default 'CHARACTER' type. - STRING_B Shall be of default 'CHARACTER' type. - -_Return value_: - Returns '.TRUE.' if 'STRING_A >= STRING_B', and '.FALSE.' - otherwise, based on the ASCII ordering. - -_Specific names_: - Name Argument Return type Standard - 'LGE(STRING_A, 'CHARACTER' 'LOGICAL' Fortran 77 and - STRING_B)' later - -_See also_: - *note LGT::, *note LLE::, *note LLT:: - - -File: gfortran.info, Node: LGT, Next: LINK, Prev: LGE, Up: Intrinsic Procedures - -8.147 'LGT' -- Lexical greater than -=================================== - -_Description_: - Determines whether one string is lexically greater than another - string, where the two strings are interpreted as containing ASCII - character codes. If the String A and String B are not the same - length, the shorter is compared as if spaces were appended to it to - form a value that has the same length as the longer. - - In general, the lexical comparison intrinsics 'LGE', 'LGT', 'LLE', - and 'LLT' differ from the corresponding intrinsic operators '.GE.', - '.GT.', '.LE.', and '.LT.', in that the latter use the processor's - character ordering (which is not ASCII on some targets), whereas - the former always use the ASCII ordering. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LGT(STRING_A, STRING_B)' - -_Arguments_: - STRING_A Shall be of default 'CHARACTER' type. - STRING_B Shall be of default 'CHARACTER' type. - -_Return value_: - Returns '.TRUE.' if 'STRING_A > STRING_B', and '.FALSE.' otherwise, - based on the ASCII ordering. - -_Specific names_: - Name Argument Return type Standard - 'LGT(STRING_A, 'CHARACTER' 'LOGICAL' Fortran 77 and - STRING_B)' later - -_See also_: - *note LGE::, *note LLE::, *note LLT:: - - -File: gfortran.info, Node: LINK, Next: LLE, Prev: LGT, Up: Intrinsic Procedures - -8.148 'LINK' -- Create a hard link -================================== - -_Description_: - Makes a (hard) link from file PATH1 to PATH2. A null character - ('CHAR(0)') can be used to mark the end of the names in PATH1 and - PATH2; otherwise, trailing blanks in the file names are ignored. - If the STATUS argument is supplied, it contains 0 on success or a - nonzero error code upon return; see 'link(2)'. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL LINK(PATH1, PATH2 [, STATUS])' - 'STATUS = LINK(PATH1, PATH2)' - -_Arguments_: - PATH1 Shall be of default 'CHARACTER' type. - PATH2 Shall be of default 'CHARACTER' type. - STATUS (Optional) Shall be of default 'INTEGER' type. - -_See also_: - *note SYMLNK::, *note UNLINK:: - - -File: gfortran.info, Node: LLE, Next: LLT, Prev: LINK, Up: Intrinsic Procedures - -8.149 'LLE' -- Lexical less than or equal -========================================= - -_Description_: - Determines whether one string is lexically less than or equal to - another string, where the two strings are interpreted as containing - ASCII character codes. If the String A and String B are not the - same length, the shorter is compared as if spaces were appended to - it to form a value that has the same length as the longer. - - In general, the lexical comparison intrinsics 'LGE', 'LGT', 'LLE', - and 'LLT' differ from the corresponding intrinsic operators '.GE.', - '.GT.', '.LE.', and '.LT.', in that the latter use the processor's - character ordering (which is not ASCII on some targets), whereas - the former always use the ASCII ordering. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LLE(STRING_A, STRING_B)' - -_Arguments_: - STRING_A Shall be of default 'CHARACTER' type. - STRING_B Shall be of default 'CHARACTER' type. - -_Return value_: - Returns '.TRUE.' if 'STRING_A <= STRING_B', and '.FALSE.' - otherwise, based on the ASCII ordering. - -_Specific names_: - Name Argument Return type Standard - 'LLE(STRING_A, 'CHARACTER' 'LOGICAL' Fortran 77 and - STRING_B)' later - -_See also_: - *note LGE::, *note LGT::, *note LLT:: - - -File: gfortran.info, Node: LLT, Next: LNBLNK, Prev: LLE, Up: Intrinsic Procedures - -8.150 'LLT' -- Lexical less than -================================ - -_Description_: - Determines whether one string is lexically less than another - string, where the two strings are interpreted as containing ASCII - character codes. If the String A and String B are not the same - length, the shorter is compared as if spaces were appended to it to - form a value that has the same length as the longer. - - In general, the lexical comparison intrinsics 'LGE', 'LGT', 'LLE', - and 'LLT' differ from the corresponding intrinsic operators '.GE.', - '.GT.', '.LE.', and '.LT.', in that the latter use the processor's - character ordering (which is not ASCII on some targets), whereas - the former always use the ASCII ordering. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LLT(STRING_A, STRING_B)' - -_Arguments_: - STRING_A Shall be of default 'CHARACTER' type. - STRING_B Shall be of default 'CHARACTER' type. - -_Return value_: - Returns '.TRUE.' if 'STRING_A < STRING_B', and '.FALSE.' otherwise, - based on the ASCII ordering. - -_Specific names_: - Name Argument Return type Standard - 'LLT(STRING_A, 'CHARACTER' 'LOGICAL' Fortran 77 and - STRING_B)' later - -_See also_: - *note LGE::, *note LGT::, *note LLE:: - - -File: gfortran.info, Node: LNBLNK, Next: LOC, Prev: LLT, Up: Intrinsic Procedures - -8.151 'LNBLNK' -- Index of the last non-blank character in a string -=================================================================== - -_Description_: - Returns the length of a character string, ignoring any trailing - blanks. This is identical to the standard 'LEN_TRIM' intrinsic, - and is only included for backwards compatibility. - -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LNBLNK(STRING)' - -_Arguments_: - STRING Shall be a scalar of type 'CHARACTER', with - 'INTENT(IN)' - -_Return value_: - The return value is of 'INTEGER(kind=4)' type. - -_See also_: - *note INDEX intrinsic::, *note LEN_TRIM:: - - -File: gfortran.info, Node: LOC, Next: LOG, Prev: LNBLNK, Up: Intrinsic Procedures - -8.152 'LOC' -- Returns the address of a variable -================================================ - -_Description_: - 'LOC(X)' returns the address of X as an integer. - -_Standard_: - GNU extension - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = LOC(X)' - -_Arguments_: - X Variable of any type. - -_Return value_: - The return value is of type 'INTEGER', with a 'KIND' corresponding - to the size (in bytes) of a memory address on the target machine. - -_Example_: - program test_loc - integer :: i - real :: r - i = loc(r) - print *, i - end program test_loc - - -File: gfortran.info, Node: LOG, Next: LOG10, Prev: LOC, Up: Intrinsic Procedures - -8.153 'LOG' -- Natural logarithm function -========================================= - -_Description_: - 'LOG(X)' computes the natural logarithm of X, i.e. the logarithm - to the base e. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LOG(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value is of type 'REAL' or 'COMPLEX'. The kind type - parameter is the same as X. If X is 'COMPLEX', the imaginary part - \omega is in the range -\pi \leq \omega \leq \pi. - -_Example_: - program test_log - real(8) :: x = 2.7182818284590451_8 - complex :: z = (1.0, 2.0) - x = log(x) ! will yield (approximately) 1 - z = log(z) - end program test_log - -_Specific names_: - Name Argument Return type Standard - 'ALOG(X)' 'REAL(4) X' 'REAL(4)' f95, gnu - 'DLOG(X)' 'REAL(8) X' 'REAL(8)' f95, gnu - 'CLOG(X)' 'COMPLEX(4) 'COMPLEX(4)' f95, gnu - X' - 'ZLOG(X)' 'COMPLEX(8) 'COMPLEX(8)' f95, gnu - X' - 'CDLOG(X)' 'COMPLEX(8) 'COMPLEX(8)' f95, gnu - X' - - -File: gfortran.info, Node: LOG10, Next: LOG_GAMMA, Prev: LOG, Up: Intrinsic Procedures - -8.154 'LOG10' -- Base 10 logarithm function -=========================================== - -_Description_: - 'LOG10(X)' computes the base 10 logarithm of X. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LOG10(X)' - -_Arguments_: - X The type shall be 'REAL'. - -_Return value_: - The return value is of type 'REAL' or 'COMPLEX'. The kind type - parameter is the same as X. - -_Example_: - program test_log10 - real(8) :: x = 10.0_8 - x = log10(x) - end program test_log10 - -_Specific names_: - Name Argument Return type Standard - 'ALOG10(X)' 'REAL(4) X' 'REAL(4)' Fortran 95 and - later - 'DLOG10(X)' 'REAL(8) X' 'REAL(8)' Fortran 95 and - later - - -File: gfortran.info, Node: LOG_GAMMA, Next: LOGICAL, Prev: LOG10, Up: Intrinsic Procedures - -8.155 'LOG_GAMMA' -- Logarithm of the Gamma function -==================================================== - -_Description_: - 'LOG_GAMMA(X)' computes the natural logarithm of the absolute value - of the Gamma (\Gamma) function. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'X = LOG_GAMMA(X)' - -_Arguments_: - X Shall be of type 'REAL' and neither zero nor a - negative integer. - -_Return value_: - The return value is of type 'REAL' of the same kind as X. - -_Example_: - program test_log_gamma - real :: x = 1.0 - x = lgamma(x) ! returns 0.0 - end program test_log_gamma - -_Specific names_: - Name Argument Return type Standard - 'LGAMMA(X)' 'REAL(4) X' 'REAL(4)' GNU Extension - 'ALGAMA(X)' 'REAL(4) X' 'REAL(4)' GNU Extension - 'DLGAMA(X)' 'REAL(8) X' 'REAL(8)' GNU Extension - -_See also_: - Gamma function: *note GAMMA:: - - -File: gfortran.info, Node: LOGICAL, Next: LONG, Prev: LOG_GAMMA, Up: Intrinsic Procedures - -8.156 'LOGICAL' -- Convert to logical type -========================================== - -_Description_: - Converts one kind of 'LOGICAL' variable to another. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LOGICAL(L [, KIND])' - -_Arguments_: - L The type shall be 'LOGICAL'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is a 'LOGICAL' value equal to L, with a kind - corresponding to KIND, or of the default logical kind if KIND is - not given. - -_See also_: - *note INT::, *note REAL::, *note CMPLX:: - - -File: gfortran.info, Node: LONG, Next: LSHIFT, Prev: LOGICAL, Up: Intrinsic Procedures - -8.157 'LONG' -- Convert to integer type -======================================= - -_Description_: - Convert to a 'KIND=4' integer type, which is the same size as a C - 'long' integer. This is equivalent to the standard 'INT' intrinsic - with an optional argument of 'KIND=4', and is only included for - backwards compatibility. - -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LONG(A)' - -_Arguments_: - A Shall be of type 'INTEGER', 'REAL', or - 'COMPLEX'. - -_Return value_: - The return value is a 'INTEGER(4)' variable. - -_See also_: - *note INT::, *note INT2::, *note INT8:: - - -File: gfortran.info, Node: LSHIFT, Next: LSTAT, Prev: LONG, Up: Intrinsic Procedures - -8.158 'LSHIFT' -- Left shift bits -================================= - -_Description_: - 'LSHIFT' returns a value corresponding to I with all of the bits - shifted left by SHIFT places. If the absolute value of SHIFT is - greater than 'BIT_SIZE(I)', the value is undefined. Bits shifted - out from the left end are lost; zeros are shifted in from the - opposite end. - - This function has been superseded by the 'ISHFT' intrinsic, which - is standard in Fortran 95 and later, and the 'SHIFTL' intrinsic, - which is standard in Fortran 2008 and later. - -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = LSHIFT(I, SHIFT)' - -_Arguments_: - I The type shall be 'INTEGER'. - SHIFT The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note ISHFT::, *note ISHFTC::, *note RSHIFT::, *note SHIFTA::, - *note SHIFTL::, *note SHIFTR:: - - -File: gfortran.info, Node: LSTAT, Next: LTIME, Prev: LSHIFT, Up: Intrinsic Procedures - -8.159 'LSTAT' -- Get file status -================================ - -_Description_: - 'LSTAT' is identical to *note STAT::, except that if path is a - symbolic link, then the link itself is statted, not the file that - it refers to. - - The elements in 'VALUES' are the same as described by *note STAT::. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL LSTAT(NAME, VALUES [, STATUS])' - 'STATUS = LSTAT(NAME, VALUES)' - -_Arguments_: - NAME The type shall be 'CHARACTER' of the default - kind, a valid path within the file system. - VALUES The type shall be 'INTEGER(4), DIMENSION(13)'. - STATUS (Optional) status flag of type 'INTEGER(4)'. - Returns 0 on success and a system specific error - code otherwise. - -_Example_: - See *note STAT:: for an example. - -_See also_: - To stat an open file: *note FSTAT::, to stat a file: *note STAT:: - - -File: gfortran.info, Node: LTIME, Next: MALLOC, Prev: LSTAT, Up: Intrinsic Procedures - -8.160 'LTIME' -- Convert time to local time info -================================================ - -_Description_: - Given a system time value TIME (as provided by the 'TIME8' - intrinsic), fills VALUES with values extracted from it appropriate - to the local time zone using 'localtime(3)'. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL LTIME(TIME, VALUES)' - -_Arguments_: - TIME An 'INTEGER' scalar expression corresponding to - a system time, with 'INTENT(IN)'. - VALUES A default 'INTEGER' array with 9 elements, with - 'INTENT(OUT)'. - -_Return value_: - The elements of VALUES are assigned as follows: - 1. Seconds after the minute, range 0-59 or 0-61 to allow for leap - seconds - 2. Minutes after the hour, range 0-59 - 3. Hours past midnight, range 0-23 - 4. Day of month, range 0-31 - 5. Number of months since January, range 0-12 - 6. Years since 1900 - 7. Number of days since Sunday, range 0-6 - 8. Days since January 1 - 9. Daylight savings indicator: positive if daylight savings is in - effect, zero if not, and negative if the information is not - available. - -_See also_: - *note CTIME::, *note GMTIME::, *note TIME::, *note TIME8:: - - -File: gfortran.info, Node: MALLOC, Next: MASKL, Prev: LTIME, Up: Intrinsic Procedures - -8.161 'MALLOC' -- Allocate dynamic memory -========================================= - -_Description_: - 'MALLOC(SIZE)' allocates SIZE bytes of dynamic memory and returns - the address of the allocated memory. The 'MALLOC' intrinsic is an - extension intended to be used with Cray pointers, and is provided - in GNU Fortran to allow the user to compile legacy code. For new - code using Fortran 95 pointers, the memory allocation intrinsic is - 'ALLOCATE'. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'PTR = MALLOC(SIZE)' - -_Arguments_: - SIZE The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER(K)', with K such that - variables of type 'INTEGER(K)' have the same size as C pointers - ('sizeof(void *)'). - -_Example_: - The following example demonstrates the use of 'MALLOC' and 'FREE' - with Cray pointers. - - program test_malloc - implicit none - integer i - real*8 x(*), z - pointer(ptr_x,x) - - ptr_x = malloc(20*8) - do i = 1, 20 - x(i) = sqrt(1.0d0 / i) - end do - z = 0 - do i = 1, 20 - z = z + x(i) - print *, z - end do - call free(ptr_x) - end program test_malloc - -_See also_: - *note FREE:: - - -File: gfortran.info, Node: MASKL, Next: MASKR, Prev: MALLOC, Up: Intrinsic Procedures - -8.162 'MASKL' -- Left justified mask -==================================== - -_Description_: - 'MASKL(I[, KIND])' has its leftmost I bits set to 1, and the - remaining bits set to 0. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = MASKL(I[, KIND])' - -_Arguments_: - I Shall be of type 'INTEGER'. - KIND Shall be a scalar constant expression of type - 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER'. If KIND is present, it - specifies the kind value of the return type; otherwise, it is of - the default integer kind. - -_See also_: - *note MASKR:: - - -File: gfortran.info, Node: MASKR, Next: MATMUL, Prev: MASKL, Up: Intrinsic Procedures - -8.163 'MASKR' -- Right justified mask -===================================== - -_Description_: - 'MASKL(I[, KIND])' has its rightmost I bits set to 1, and the - remaining bits set to 0. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = MASKR(I[, KIND])' - -_Arguments_: - I Shall be of type 'INTEGER'. - KIND Shall be a scalar constant expression of type - 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER'. If KIND is present, it - specifies the kind value of the return type; otherwise, it is of - the default integer kind. - -_See also_: - *note MASKL:: - - -File: gfortran.info, Node: MATMUL, Next: MAX, Prev: MASKR, Up: Intrinsic Procedures - -8.164 'MATMUL' -- matrix multiplication -======================================= - -_Description_: - Performs a matrix multiplication on numeric or logical arguments. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = MATMUL(MATRIX_A, MATRIX_B)' - -_Arguments_: - MATRIX_A An array of 'INTEGER', 'REAL', 'COMPLEX', or - 'LOGICAL' type, with a rank of one or two. - MATRIX_B An array of 'INTEGER', 'REAL', or 'COMPLEX' type - if MATRIX_A is of a numeric type; otherwise, an - array of 'LOGICAL' type. The rank shall be one - or two, and the first (or only) dimension of - MATRIX_B shall be equal to the last (or only) - dimension of MATRIX_A. - -_Return value_: - The matrix product of MATRIX_A and MATRIX_B. The type and kind of - the result follow the usual type and kind promotion rules, as for - the '*' or '.AND.' operators. - -_See also_: - - -File: gfortran.info, Node: MAX, Next: MAXEXPONENT, Prev: MATMUL, Up: Intrinsic Procedures - -8.165 'MAX' -- Maximum value of an argument list -================================================ - -_Description_: - Returns the argument with the largest (most positive) value. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = MAX(A1, A2 [, A3 [, ...]])' - -_Arguments_: - A1 The type shall be 'INTEGER' or 'REAL'. - A2, A3, An expression of the same type and kind as A1. - ... (As a GNU extension, arguments of different - kinds are permitted.) - -_Return value_: - The return value corresponds to the maximum value among the - arguments, and has the same type and kind as the first argument. - -_Specific names_: - Name Argument Return type Standard - 'MAX0(A1)' 'INTEGER(4) 'INTEGER(4)' Fortran 77 and - A1' later - 'AMAX0(A1)' 'INTEGER(4) 'REAL(MAX(X))' Fortran 77 and - A1' later - 'MAX1(A1)' 'REAL A1' 'INT(MAX(X))' Fortran 77 and - later - 'AMAX1(A1)' 'REAL(4) A1' 'REAL(4)' Fortran 77 and - later - 'DMAX1(A1)' 'REAL(8) A1' 'REAL(8)' Fortran 77 and - later - -_See also_: - *note MAXLOC:: *note MAXVAL::, *note MIN:: - - -File: gfortran.info, Node: MAXEXPONENT, Next: MAXLOC, Prev: MAX, Up: Intrinsic Procedures - -8.166 'MAXEXPONENT' -- Maximum exponent of a real kind -====================================================== - -_Description_: - 'MAXEXPONENT(X)' returns the maximum exponent in the model of the - type of 'X'. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = MAXEXPONENT(X)' - -_Arguments_: - X Shall be of type 'REAL'. - -_Return value_: - The return value is of type 'INTEGER' and of the default integer - kind. - -_Example_: - program exponents - real(kind=4) :: x - real(kind=8) :: y - - print *, minexponent(x), maxexponent(x) - print *, minexponent(y), maxexponent(y) - end program exponents - - -File: gfortran.info, Node: MAXLOC, Next: MAXVAL, Prev: MAXEXPONENT, Up: Intrinsic Procedures - -8.167 'MAXLOC' -- Location of the maximum value within an array -=============================================================== - -_Description_: - Determines the location of the element in the array with the - maximum value, or, if the DIM argument is supplied, determines the - locations of the maximum element along each row of the array in the - DIM direction. If MASK is present, only the elements for which - MASK is '.TRUE.' are considered. If more than one element in the - array has the maximum value, the location returned is that of the - first such element in array element order. If the array has zero - size, or all of the elements of MASK are '.FALSE.', then the result - is an array of zeroes. Similarly, if DIM is supplied and all of - the elements of MASK along a given row are zero, the result value - for that row is zero. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = MAXLOC(ARRAY, DIM [, MASK])' - 'RESULT = MAXLOC(ARRAY [, MASK])' - -_Arguments_: - ARRAY Shall be an array of type 'INTEGER' or 'REAL'. - DIM (Optional) Shall be a scalar of type 'INTEGER', - with a value between one and the rank of ARRAY, - inclusive. It may not be an optional dummy - argument. - MASK Shall be an array of type 'LOGICAL', and - conformable with ARRAY. - -_Return value_: - If DIM is absent, the result is a rank-one array with a length - equal to the rank of ARRAY. If DIM is present, the result is an - array with a rank one less than the rank of ARRAY, and a size - corresponding to the size of ARRAY with the DIM dimension removed. - If DIM is present and ARRAY has a rank of one, the result is a - scalar. In all cases, the result is of default 'INTEGER' type. - -_See also_: - *note MAX::, *note MAXVAL:: - - -File: gfortran.info, Node: MAXVAL, Next: MCLOCK, Prev: MAXLOC, Up: Intrinsic Procedures - -8.168 'MAXVAL' -- Maximum value of an array -=========================================== - -_Description_: - Determines the maximum value of the elements in an array value, or, - if the DIM argument is supplied, determines the maximum value along - each row of the array in the DIM direction. If MASK is present, - only the elements for which MASK is '.TRUE.' are considered. If - the array has zero size, or all of the elements of MASK are - '.FALSE.', then the result is '-HUGE(ARRAY)' if ARRAY is numeric, - or a string of nulls if ARRAY is of character type. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = MAXVAL(ARRAY, DIM [, MASK])' - 'RESULT = MAXVAL(ARRAY [, MASK])' - -_Arguments_: - ARRAY Shall be an array of type 'INTEGER' or 'REAL'. - DIM (Optional) Shall be a scalar of type 'INTEGER', - with a value between one and the rank of ARRAY, - inclusive. It may not be an optional dummy - argument. - MASK Shall be an array of type 'LOGICAL', and - conformable with ARRAY. - -_Return value_: - If DIM is absent, or if ARRAY has a rank of one, the result is a - scalar. If DIM is present, the result is an array with a rank one - less than the rank of ARRAY, and a size corresponding to the size - of ARRAY with the DIM dimension removed. In all cases, the result - is of the same type and kind as ARRAY. - -_See also_: - *note MAX::, *note MAXLOC:: - - -File: gfortran.info, Node: MCLOCK, Next: MCLOCK8, Prev: MAXVAL, Up: Intrinsic Procedures - -8.169 'MCLOCK' -- Time function -=============================== - -_Description_: - Returns the number of clock ticks since the start of the process, - based on the function 'clock(3)' in the C standard library. - - This intrinsic is not fully portable, such as to systems with - 32-bit 'INTEGER' types but supporting times wider than 32 bits. - Therefore, the values returned by this intrinsic might be, or - become, negative, or numerically less than previous values, during - a single run of the compiled program. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = MCLOCK()' - -_Return value_: - The return value is a scalar of type 'INTEGER(4)', equal to the - number of clock ticks since the start of the process, or '-1' if - the system does not support 'clock(3)'. - -_See also_: - *note CTIME::, *note GMTIME::, *note LTIME::, *note MCLOCK::, *note - TIME:: - - -File: gfortran.info, Node: MCLOCK8, Next: MERGE, Prev: MCLOCK, Up: Intrinsic Procedures - -8.170 'MCLOCK8' -- Time function (64-bit) -========================================= - -_Description_: - Returns the number of clock ticks since the start of the process, - based on the function 'clock(3)' in the C standard library. - - _Warning:_ this intrinsic does not increase the range of the timing - values over that returned by 'clock(3)'. On a system with a 32-bit - 'clock(3)', 'MCLOCK8' will return a 32-bit value, even though it is - converted to a 64-bit 'INTEGER(8)' value. That means overflows of - the 32-bit value can still occur. Therefore, the values returned - by this intrinsic might be or become negative or numerically less - than previous values during a single run of the compiled program. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = MCLOCK8()' - -_Return value_: - The return value is a scalar of type 'INTEGER(8)', equal to the - number of clock ticks since the start of the process, or '-1' if - the system does not support 'clock(3)'. - -_See also_: - *note CTIME::, *note GMTIME::, *note LTIME::, *note MCLOCK::, *note - TIME8:: - - -File: gfortran.info, Node: MERGE, Next: MERGE_BITS, Prev: MCLOCK8, Up: Intrinsic Procedures - -8.171 'MERGE' -- Merge variables -================================ - -_Description_: - Select values from two arrays according to a logical mask. The - result is equal to TSOURCE if MASK is '.TRUE.', or equal to FSOURCE - if it is '.FALSE.'. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = MERGE(TSOURCE, FSOURCE, MASK)' - -_Arguments_: - TSOURCE May be of any type. - FSOURCE Shall be of the same type and type parameters as - TSOURCE. - MASK Shall be of type 'LOGICAL'. - -_Return value_: - The result is of the same type and type parameters as TSOURCE. - - -File: gfortran.info, Node: MERGE_BITS, Next: MIN, Prev: MERGE, Up: Intrinsic Procedures - -8.172 'MERGE_BITS' -- Merge of bits under mask -============================================== - -_Description_: - 'MERGE_BITS(I, J, MASK)' merges the bits of I and J as determined - by the mask. The i-th bit of the result is equal to the i-th bit - of I if the i-th bit of MASK is 1; it is equal to the i-th bit of J - otherwise. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = MERGE_BITS(I, J, MASK)' - -_Arguments_: - I Shall be of type 'INTEGER'. - J Shall be of type 'INTEGER' and of the same kind - as I. - MASK Shall be of type 'INTEGER' and of the same kind - as I. - -_Return value_: - The result is of the same type and kind as I. - - -File: gfortran.info, Node: MIN, Next: MINEXPONENT, Prev: MERGE_BITS, Up: Intrinsic Procedures - -8.173 'MIN' -- Minimum value of an argument list -================================================ - -_Description_: - Returns the argument with the smallest (most negative) value. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = MIN(A1, A2 [, A3, ...])' - -_Arguments_: - A1 The type shall be 'INTEGER' or 'REAL'. - A2, A3, An expression of the same type and kind as A1. - ... (As a GNU extension, arguments of different - kinds are permitted.) - -_Return value_: - The return value corresponds to the maximum value among the - arguments, and has the same type and kind as the first argument. - -_Specific names_: - Name Argument Return type Standard - 'MIN0(A1)' 'INTEGER(4) 'INTEGER(4)' Fortran 77 and - A1' later - 'AMIN0(A1)' 'INTEGER(4) 'REAL(4)' Fortran 77 and - A1' later - 'MIN1(A1)' 'REAL A1' 'INTEGER(4)' Fortran 77 and - later - 'AMIN1(A1)' 'REAL(4) A1' 'REAL(4)' Fortran 77 and - later - 'DMIN1(A1)' 'REAL(8) A1' 'REAL(8)' Fortran 77 and - later - -_See also_: - *note MAX::, *note MINLOC::, *note MINVAL:: - - -File: gfortran.info, Node: MINEXPONENT, Next: MINLOC, Prev: MIN, Up: Intrinsic Procedures - -8.174 'MINEXPONENT' -- Minimum exponent of a real kind -====================================================== - -_Description_: - 'MINEXPONENT(X)' returns the minimum exponent in the model of the - type of 'X'. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = MINEXPONENT(X)' - -_Arguments_: - X Shall be of type 'REAL'. - -_Return value_: - The return value is of type 'INTEGER' and of the default integer - kind. - -_Example_: - See 'MAXEXPONENT' for an example. - - -File: gfortran.info, Node: MINLOC, Next: MINVAL, Prev: MINEXPONENT, Up: Intrinsic Procedures - -8.175 'MINLOC' -- Location of the minimum value within an array -=============================================================== - -_Description_: - Determines the location of the element in the array with the - minimum value, or, if the DIM argument is supplied, determines the - locations of the minimum element along each row of the array in the - DIM direction. If MASK is present, only the elements for which - MASK is '.TRUE.' are considered. If more than one element in the - array has the minimum value, the location returned is that of the - first such element in array element order. If the array has zero - size, or all of the elements of MASK are '.FALSE.', then the result - is an array of zeroes. Similarly, if DIM is supplied and all of - the elements of MASK along a given row are zero, the result value - for that row is zero. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = MINLOC(ARRAY, DIM [, MASK])' - 'RESULT = MINLOC(ARRAY [, MASK])' - -_Arguments_: - ARRAY Shall be an array of type 'INTEGER' or 'REAL'. - DIM (Optional) Shall be a scalar of type 'INTEGER', - with a value between one and the rank of ARRAY, - inclusive. It may not be an optional dummy - argument. - MASK Shall be an array of type 'LOGICAL', and - conformable with ARRAY. - -_Return value_: - If DIM is absent, the result is a rank-one array with a length - equal to the rank of ARRAY. If DIM is present, the result is an - array with a rank one less than the rank of ARRAY, and a size - corresponding to the size of ARRAY with the DIM dimension removed. - If DIM is present and ARRAY has a rank of one, the result is a - scalar. In all cases, the result is of default 'INTEGER' type. - -_See also_: - *note MIN::, *note MINVAL:: - - -File: gfortran.info, Node: MINVAL, Next: MOD, Prev: MINLOC, Up: Intrinsic Procedures - -8.176 'MINVAL' -- Minimum value of an array -=========================================== - -_Description_: - Determines the minimum value of the elements in an array value, or, - if the DIM argument is supplied, determines the minimum value along - each row of the array in the DIM direction. If MASK is present, - only the elements for which MASK is '.TRUE.' are considered. If - the array has zero size, or all of the elements of MASK are - '.FALSE.', then the result is 'HUGE(ARRAY)' if ARRAY is numeric, or - a string of 'CHAR(255)' characters if ARRAY is of character type. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = MINVAL(ARRAY, DIM [, MASK])' - 'RESULT = MINVAL(ARRAY [, MASK])' - -_Arguments_: - ARRAY Shall be an array of type 'INTEGER' or 'REAL'. - DIM (Optional) Shall be a scalar of type 'INTEGER', - with a value between one and the rank of ARRAY, - inclusive. It may not be an optional dummy - argument. - MASK Shall be an array of type 'LOGICAL', and - conformable with ARRAY. - -_Return value_: - If DIM is absent, or if ARRAY has a rank of one, the result is a - scalar. If DIM is present, the result is an array with a rank one - less than the rank of ARRAY, and a size corresponding to the size - of ARRAY with the DIM dimension removed. In all cases, the result - is of the same type and kind as ARRAY. - -_See also_: - *note MIN::, *note MINLOC:: - - -File: gfortran.info, Node: MOD, Next: MODULO, Prev: MINVAL, Up: Intrinsic Procedures - -8.177 'MOD' -- Remainder function -================================= - -_Description_: - 'MOD(A,P)' computes the remainder of the division of A by P. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = MOD(A, P)' - -_Arguments_: - A Shall be a scalar of type 'INTEGER' or 'REAL'. - P Shall be a scalar of the same type and kind as A - and not equal to zero. - -_Return value_: - The return value is the result of 'A - (INT(A/P) * P)'. The type - and kind of the return value is the same as that of the arguments. - The returned value has the same sign as A and a magnitude less than - the magnitude of P. - -_Example_: - program test_mod - print *, mod(17,3) - print *, mod(17.5,5.5) - print *, mod(17.5d0,5.5) - print *, mod(17.5,5.5d0) - - print *, mod(-17,3) - print *, mod(-17.5,5.5) - print *, mod(-17.5d0,5.5) - print *, mod(-17.5,5.5d0) - - print *, mod(17,-3) - print *, mod(17.5,-5.5) - print *, mod(17.5d0,-5.5) - print *, mod(17.5,-5.5d0) - end program test_mod - -_Specific names_: - Name Arguments Return type Standard - 'MOD(A,P)' 'INTEGER 'INTEGER' Fortran 95 and - A,P' later - 'AMOD(A,P)' 'REAL(4) 'REAL(4)' Fortran 95 and - A,P' later - 'DMOD(A,P)' 'REAL(8) 'REAL(8)' Fortran 95 and - A,P' later - -_See also_: - *note MODULO:: - - -File: gfortran.info, Node: MODULO, Next: MOVE_ALLOC, Prev: MOD, Up: Intrinsic Procedures - -8.178 'MODULO' -- Modulo function -================================= - -_Description_: - 'MODULO(A,P)' computes the A modulo P. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = MODULO(A, P)' - -_Arguments_: - A Shall be a scalar of type 'INTEGER' or 'REAL'. - P Shall be a scalar of the same type and kind as - A. It shall not be zero. - -_Return value_: - The type and kind of the result are those of the arguments. - If A and P are of type 'INTEGER': - 'MODULO(A,P)' has the value R such that 'A=Q*P+R', where Q is - an integer and R is between 0 (inclusive) and P (exclusive). - If A and P are of type 'REAL': - 'MODULO(A,P)' has the value of 'A - FLOOR (A / P) * P'. - The returned value has the same sign as P and a magnitude less than - the magnitude of P. - -_Example_: - program test_modulo - print *, modulo(17,3) - print *, modulo(17.5,5.5) - - print *, modulo(-17,3) - print *, modulo(-17.5,5.5) - - print *, modulo(17,-3) - print *, modulo(17.5,-5.5) - end program - -_See also_: - *note MOD:: - - -File: gfortran.info, Node: MOVE_ALLOC, Next: MVBITS, Prev: MODULO, Up: Intrinsic Procedures - -8.179 'MOVE_ALLOC' -- Move allocation from one object to another -================================================================ - -_Description_: - 'MOVE_ALLOC(FROM, TO)' moves the allocation from FROM to TO. FROM - will become deallocated in the process. - -_Standard_: - Fortran 2003 and later - -_Class_: - Pure subroutine - -_Syntax_: - 'CALL MOVE_ALLOC(FROM, TO)' - -_Arguments_: - FROM 'ALLOCATABLE', 'INTENT(INOUT)', may be of any - type and kind. - TO 'ALLOCATABLE', 'INTENT(OUT)', shall be of the - same type, kind and rank as FROM. - -_Return value_: - None - -_Example_: - program test_move_alloc - integer, allocatable :: a(:), b(:) - - allocate(a(3)) - a = [ 1, 2, 3 ] - call move_alloc(a, b) - print *, allocated(a), allocated(b) - print *, b - end program test_move_alloc - - -File: gfortran.info, Node: MVBITS, Next: NEAREST, Prev: MOVE_ALLOC, Up: Intrinsic Procedures - -8.180 'MVBITS' -- Move bits from one integer to another -======================================================= - -_Description_: - Moves LEN bits from positions FROMPOS through 'FROMPOS+LEN-1' of - FROM to positions TOPOS through 'TOPOS+LEN-1' of TO. The portion - of argument TO not affected by the movement of bits is unchanged. - The values of 'FROMPOS+LEN-1' and 'TOPOS+LEN-1' must be less than - 'BIT_SIZE(FROM)'. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental subroutine - -_Syntax_: - 'CALL MVBITS(FROM, FROMPOS, LEN, TO, TOPOS)' - -_Arguments_: - FROM The type shall be 'INTEGER'. - FROMPOS The type shall be 'INTEGER'. - LEN The type shall be 'INTEGER'. - TO The type shall be 'INTEGER', of the same kind as - FROM. - TOPOS The type shall be 'INTEGER'. - -_See also_: - *note IBCLR::, *note IBSET::, *note IBITS::, *note IAND::, *note - IOR::, *note IEOR:: - - -File: gfortran.info, Node: NEAREST, Next: NEW_LINE, Prev: MVBITS, Up: Intrinsic Procedures - -8.181 'NEAREST' -- Nearest representable number -=============================================== - -_Description_: - 'NEAREST(X, S)' returns the processor-representable number nearest - to 'X' in the direction indicated by the sign of 'S'. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = NEAREST(X, S)' - -_Arguments_: - X Shall be of type 'REAL'. - S Shall be of type 'REAL' and not equal to zero. - -_Return value_: - The return value is of the same type as 'X'. If 'S' is positive, - 'NEAREST' returns the processor-representable number greater than - 'X' and nearest to it. If 'S' is negative, 'NEAREST' returns the - processor-representable number smaller than 'X' and nearest to it. - -_Example_: - program test_nearest - real :: x, y - x = nearest(42.0, 1.0) - y = nearest(42.0, -1.0) - write (*,"(3(G20.15))") x, y, x - y - end program test_nearest - - -File: gfortran.info, Node: NEW_LINE, Next: NINT, Prev: NEAREST, Up: Intrinsic Procedures - -8.182 'NEW_LINE' -- New line character -====================================== - -_Description_: - 'NEW_LINE(C)' returns the new-line character. - -_Standard_: - Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = NEW_LINE(C)' - -_Arguments_: - C The argument shall be a scalar or array of the - type 'CHARACTER'. - -_Return value_: - Returns a CHARACTER scalar of length one with the new-line - character of the same kind as parameter C. - -_Example_: - program newline - implicit none - write(*,'(A)') 'This is record 1.'//NEW_LINE('A')//'This is record 2.' - end program newline - - -File: gfortran.info, Node: NINT, Next: NORM2, Prev: NEW_LINE, Up: Intrinsic Procedures - -8.183 'NINT' -- Nearest whole number -==================================== - -_Description_: - 'NINT(A)' rounds its argument to the nearest whole number. - -_Standard_: - Fortran 77 and later, with KIND argument Fortran 90 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = NINT(A [, KIND])' - -_Arguments_: - A The type of the argument shall be 'REAL'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - Returns A with the fractional portion of its magnitude eliminated - by rounding to the nearest whole number and with its sign - preserved, converted to an 'INTEGER' of the default kind. - -_Example_: - program test_nint - real(4) x4 - real(8) x8 - x4 = 1.234E0_4 - x8 = 4.321_8 - print *, nint(x4), idnint(x8) - end program test_nint - -_Specific names_: - Name Argument Return Type Standard - 'NINT(A)' 'REAL(4) A' 'INTEGER' Fortran 95 and - later - 'IDNINT(A)' 'REAL(8) A' 'INTEGER' Fortran 95 and - later - -_See also_: - *note CEILING::, *note FLOOR:: - - -File: gfortran.info, Node: NORM2, Next: NOT, Prev: NINT, Up: Intrinsic Procedures - -8.184 'NORM2' -- Euclidean vector norms -======================================= - -_Description_: - Calculates the Euclidean vector norm (L_2 norm) of of ARRAY along - dimension DIM. - -_Standard_: - Fortran 2008 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = NORM2(ARRAY[, DIM])' - -_Arguments_: - ARRAY Shall be an array of type 'REAL' - DIM (Optional) shall be a scalar of type 'INTEGER' - with a value in the range from 1 to n, where n - equals the rank of ARRAY. - -_Return value_: - The result is of the same type as ARRAY. - - If DIM is absent, a scalar with the square root of the sum of all - elements in ARRAY squared is returned. Otherwise, an array of rank - n-1, where n equals the rank of ARRAY, and a shape similar to that - of ARRAY with dimension DIM dropped is returned. - -_Example_: - PROGRAM test_sum - REAL :: x(5) = [ real :: 1, 2, 3, 4, 5 ] - print *, NORM2(x) ! = sqrt(55.) ~ 7.416 - END PROGRAM - - -File: gfortran.info, Node: NOT, Next: NULL, Prev: NORM2, Up: Intrinsic Procedures - -8.185 'NOT' -- Logical negation -=============================== - -_Description_: - 'NOT' returns the bitwise Boolean inverse of I. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = NOT(I)' - -_Arguments_: - I The type shall be 'INTEGER'. - -_Return value_: - The return type is 'INTEGER', of the same kind as the argument. - -_See also_: - *note IAND::, *note IEOR::, *note IOR::, *note IBITS::, *note - IBSET::, *note IBCLR:: - - -File: gfortran.info, Node: NULL, Next: NUM_IMAGES, Prev: NOT, Up: Intrinsic Procedures - -8.186 'NULL' -- Function that returns an disassociated pointer -============================================================== - -_Description_: - Returns a disassociated pointer. - - If MOLD is present, a disassociated pointer of the same type is - returned, otherwise the type is determined by context. - - In Fortran 95, MOLD is optional. Please note that Fortran 2003 - includes cases where it is required. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'PTR => NULL([MOLD])' - -_Arguments_: - MOLD (Optional) shall be a pointer of any association - status and of any type. - -_Return value_: - A disassociated pointer. - -_Example_: - REAL, POINTER, DIMENSION(:) :: VEC => NULL () - -_See also_: - *note ASSOCIATED:: - - -File: gfortran.info, Node: NUM_IMAGES, Next: OR, Prev: NULL, Up: Intrinsic Procedures - -8.187 'NUM_IMAGES' -- Function that returns the number of images -================================================================ - -_Description_: - Returns the number of images. - -_Standard_: - Fortran 2008 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = NUM_IMAGES()' - -_Arguments_: None. - -_Return value_: - Scalar default-kind integer. - -_Example_: - INTEGER :: value[*] - INTEGER :: i - value = THIS_IMAGE() - SYNC ALL - IF (THIS_IMAGE() == 1) THEN - DO i = 1, NUM_IMAGES() - WRITE(*,'(2(a,i0))') 'value[', i, '] is ', value[i] - END DO - END IF - -_See also_: - *note THIS_IMAGE::, *note IMAGE_INDEX:: - - -File: gfortran.info, Node: OR, Next: PACK, Prev: NUM_IMAGES, Up: Intrinsic Procedures - -8.188 'OR' -- Bitwise logical OR -================================ - -_Description_: - Bitwise logical 'OR'. - - This intrinsic routine is provided for backwards compatibility with - GNU Fortran 77. For integer arguments, programmers should consider - the use of the *note IOR:: intrinsic defined by the Fortran - standard. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = OR(I, J)' - -_Arguments_: - I The type shall be either a scalar 'INTEGER' type - or a scalar 'LOGICAL' type. - J The type shall be the same as the type of J. - -_Return value_: - The return type is either a scalar 'INTEGER' or a scalar 'LOGICAL'. - If the kind type parameters differ, then the smaller kind type is - implicitly converted to larger kind, and the return has the larger - kind. - -_Example_: - PROGRAM test_or - LOGICAL :: T = .TRUE., F = .FALSE. - INTEGER :: a, b - DATA a / Z'F' /, b / Z'3' / - - WRITE (*,*) OR(T, T), OR(T, F), OR(F, T), OR(F, F) - WRITE (*,*) OR(a, b) - END PROGRAM - -_See also_: - Fortran 95 elemental function: *note IOR:: - - -File: gfortran.info, Node: PACK, Next: PARITY, Prev: OR, Up: Intrinsic Procedures - -8.189 'PACK' -- Pack an array into an array of rank one -======================================================= - -_Description_: - Stores the elements of ARRAY in an array of rank one. - - The beginning of the resulting array is made up of elements whose - MASK equals 'TRUE'. Afterwards, positions are filled with elements - taken from VECTOR. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = PACK(ARRAY, MASK[,VECTOR])' - -_Arguments_: - ARRAY Shall be an array of any type. - MASK Shall be an array of type 'LOGICAL' and of the - same size as ARRAY. Alternatively, it may be a - 'LOGICAL' scalar. - VECTOR (Optional) shall be an array of the same type as - ARRAY and of rank one. If present, the number - of elements in VECTOR shall be equal to or - greater than the number of true elements in - MASK. If MASK is scalar, the number of elements - in VECTOR shall be equal to or greater than the - number of elements in ARRAY. - -_Return value_: - The result is an array of rank one and the same type as that of - ARRAY. If VECTOR is present, the result size is that of VECTOR, - the number of 'TRUE' values in MASK otherwise. - -_Example_: - Gathering nonzero elements from an array: - PROGRAM test_pack_1 - INTEGER :: m(6) - m = (/ 1, 0, 0, 0, 5, 0 /) - WRITE(*, FMT="(6(I0, ' '))") pack(m, m /= 0) ! "1 5" - END PROGRAM - - Gathering nonzero elements from an array and appending elements - from VECTOR: - PROGRAM test_pack_2 - INTEGER :: m(4) - m = (/ 1, 0, 0, 2 /) - WRITE(*, FMT="(4(I0, ' '))") pack(m, m /= 0, (/ 0, 0, 3, 4 /)) ! "1 2 3 4" - END PROGRAM - -_See also_: - *note UNPACK:: - - -File: gfortran.info, Node: PARITY, Next: PERROR, Prev: PACK, Up: Intrinsic Procedures - -8.190 'PARITY' -- Reduction with exclusive OR -============================================= - -_Description_: - Calculates the parity, i.e. the reduction using '.XOR.', of MASK - along dimension DIM. - -_Standard_: - Fortran 2008 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = PARITY(MASK[, DIM])' - -_Arguments_: - LOGICAL Shall be an array of type 'LOGICAL' - DIM (Optional) shall be a scalar of type 'INTEGER' - with a value in the range from 1 to n, where n - equals the rank of MASK. - -_Return value_: - The result is of the same type as MASK. - - If DIM is absent, a scalar with the parity of all elements in MASK - is returned, i.e. true if an odd number of elements is '.true.' - and false otherwise. If DIM is present, an array of rank n-1, - where n equals the rank of ARRAY, and a shape similar to that of - MASK with dimension DIM dropped is returned. - -_Example_: - PROGRAM test_sum - LOGICAL :: x(2) = [ .true., .false. ] - print *, PARITY(x) ! prints "T" (true). - END PROGRAM - - -File: gfortran.info, Node: PERROR, Next: POPCNT, Prev: PARITY, Up: Intrinsic Procedures - -8.191 'PERROR' -- Print system error message -============================================ - -_Description_: - Prints (on the C 'stderr' stream) a newline-terminated error - message corresponding to the last system error. This is prefixed - by STRING, a colon and a space. See 'perror(3)'. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL PERROR(STRING)' - -_Arguments_: - STRING A scalar of type 'CHARACTER' and of the default - kind. - -_See also_: - *note IERRNO:: - - -File: gfortran.info, Node: POPCNT, Next: POPPAR, Prev: PERROR, Up: Intrinsic Procedures - -8.192 'POPCNT' -- Number of bits set -==================================== - -_Description_: - 'POPCNT(I)' returns the number of bits set ('1' bits) in the binary - representation of 'I'. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = POPCNT(I)' - -_Arguments_: - I Shall be of type 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the default integer - kind. - -_See also_: - *note POPPAR::, *note LEADZ::, *note TRAILZ:: - -_Example_: - program test_population - print *, popcnt(127), poppar(127) - print *, popcnt(huge(0_4)), poppar(huge(0_4)) - print *, popcnt(huge(0_8)), poppar(huge(0_8)) - end program test_population - - -File: gfortran.info, Node: POPPAR, Next: PRECISION, Prev: POPCNT, Up: Intrinsic Procedures - -8.193 'POPPAR' -- Parity of the number of bits set -================================================== - -_Description_: - 'POPPAR(I)' returns parity of the integer 'I', i.e. the parity of - the number of bits set ('1' bits) in the binary representation of - 'I'. It is equal to 0 if 'I' has an even number of bits set, and 1 - for an odd number of '1' bits. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = POPPAR(I)' - -_Arguments_: - I Shall be of type 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the default integer - kind. - -_See also_: - *note POPCNT::, *note LEADZ::, *note TRAILZ:: - -_Example_: - program test_population - print *, popcnt(127), poppar(127) - print *, popcnt(huge(0_4)), poppar(huge(0_4)) - print *, popcnt(huge(0_8)), poppar(huge(0_8)) - end program test_population - - -File: gfortran.info, Node: PRECISION, Next: PRESENT, Prev: POPPAR, Up: Intrinsic Procedures - -8.194 'PRECISION' -- Decimal precision of a real kind -===================================================== - -_Description_: - 'PRECISION(X)' returns the decimal precision in the model of the - type of 'X'. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = PRECISION(X)' - -_Arguments_: - X Shall be of type 'REAL' or 'COMPLEX'. - -_Return value_: - The return value is of type 'INTEGER' and of the default integer - kind. - -_See also_: - *note SELECTED_REAL_KIND::, *note RANGE:: - -_Example_: - program prec_and_range - real(kind=4) :: x(2) - complex(kind=8) :: y - - print *, precision(x), range(x) - print *, precision(y), range(y) - end program prec_and_range - - -File: gfortran.info, Node: PRESENT, Next: PRODUCT, Prev: PRECISION, Up: Intrinsic Procedures - -8.195 'PRESENT' -- Determine whether an optional dummy argument is specified -============================================================================ - -_Description_: - Determines whether an optional dummy argument is present. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = PRESENT(A)' - -_Arguments_: - A May be of any type and may be a pointer, scalar - or array value, or a dummy procedure. It shall - be the name of an optional dummy argument - accessible within the current subroutine or - function. - -_Return value_: - Returns either 'TRUE' if the optional argument A is present, or - 'FALSE' otherwise. - -_Example_: - PROGRAM test_present - WRITE(*,*) f(), f(42) ! "F T" - CONTAINS - LOGICAL FUNCTION f(x) - INTEGER, INTENT(IN), OPTIONAL :: x - f = PRESENT(x) - END FUNCTION - END PROGRAM - - -File: gfortran.info, Node: PRODUCT, Next: RADIX, Prev: PRESENT, Up: Intrinsic Procedures - -8.196 'PRODUCT' -- Product of array elements -============================================ - -_Description_: - Multiplies the elements of ARRAY along dimension DIM if the - corresponding element in MASK is 'TRUE'. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = PRODUCT(ARRAY[, MASK])' - 'RESULT = PRODUCT(ARRAY, DIM[, MASK])' - -_Arguments_: - ARRAY Shall be an array of type 'INTEGER', 'REAL' or - 'COMPLEX'. - DIM (Optional) shall be a scalar of type 'INTEGER' - with a value in the range from 1 to n, where n - equals the rank of ARRAY. - MASK (Optional) shall be of type 'LOGICAL' and either - be a scalar or an array of the same shape as - ARRAY. - -_Return value_: - The result is of the same type as ARRAY. - - If DIM is absent, a scalar with the product of all elements in - ARRAY is returned. Otherwise, an array of rank n-1, where n equals - the rank of ARRAY, and a shape similar to that of ARRAY with - dimension DIM dropped is returned. - -_Example_: - PROGRAM test_product - INTEGER :: x(5) = (/ 1, 2, 3, 4 ,5 /) - print *, PRODUCT(x) ! all elements, product = 120 - print *, PRODUCT(x, MASK=MOD(x, 2)==1) ! odd elements, product = 15 - END PROGRAM - -_See also_: - *note SUM:: - - -File: gfortran.info, Node: RADIX, Next: RAN, Prev: PRODUCT, Up: Intrinsic Procedures - -8.197 'RADIX' -- Base of a model number -======================================= - -_Description_: - 'RADIX(X)' returns the base of the model representing the entity X. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = RADIX(X)' - -_Arguments_: - X Shall be of type 'INTEGER' or 'REAL' - -_Return value_: - The return value is a scalar of type 'INTEGER' and of the default - integer kind. - -_See also_: - *note SELECTED_REAL_KIND:: - -_Example_: - program test_radix - print *, "The radix for the default integer kind is", radix(0) - print *, "The radix for the default real kind is", radix(0.0) - end program test_radix - - -File: gfortran.info, Node: RAN, Next: RAND, Prev: RADIX, Up: Intrinsic Procedures - -8.198 'RAN' -- Real pseudo-random number -======================================== - -_Description_: - For compatibility with HP FORTRAN 77/iX, the 'RAN' intrinsic is - provided as an alias for 'RAND'. See *note RAND:: for complete - documentation. - -_Standard_: - GNU extension - -_Class_: - Function - -_See also_: - *note RAND::, *note RANDOM_NUMBER:: - - -File: gfortran.info, Node: RAND, Next: RANDOM_NUMBER, Prev: RAN, Up: Intrinsic Procedures - -8.199 'RAND' -- Real pseudo-random number -========================================= - -_Description_: - 'RAND(FLAG)' returns a pseudo-random number from a uniform - distribution between 0 and 1. If FLAG is 0, the next number in the - current sequence is returned; if FLAG is 1, the generator is - restarted by 'CALL SRAND(0)'; if FLAG has any other value, it is - used as a new seed with 'SRAND'. - - This intrinsic routine is provided for backwards compatibility with - GNU Fortran 77. It implements a simple modulo generator as - provided by 'g77'. For new code, one should consider the use of - *note RANDOM_NUMBER:: as it implements a superior algorithm. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = RAND(I)' - -_Arguments_: - I Shall be a scalar 'INTEGER' of kind 4. - -_Return value_: - The return value is of 'REAL' type and the default kind. - -_Example_: - program test_rand - integer,parameter :: seed = 86456 - - call srand(seed) - print *, rand(), rand(), rand(), rand() - print *, rand(seed), rand(), rand(), rand() - end program test_rand - -_See also_: - *note SRAND::, *note RANDOM_NUMBER:: - - -File: gfortran.info, Node: RANDOM_NUMBER, Next: RANDOM_SEED, Prev: RAND, Up: Intrinsic Procedures - -8.200 'RANDOM_NUMBER' -- Pseudo-random number -============================================= - -_Description_: - Returns a single pseudorandom number or an array of pseudorandom - numbers from the uniform distribution over the range 0 \leq x < 1. - - The runtime-library implements George Marsaglia's KISS (Keep It - Simple Stupid) random number generator (RNG). This RNG combines: - 1. The congruential generator x(n) = 69069 \cdot x(n-1) + - 1327217885 with a period of 2^{32}, - 2. A 3-shift shift-register generator with a period of 2^{32} - - 1, - 3. Two 16-bit multiply-with-carry generators with a period of - 597273182964842497 > 2^{59}. - The overall period exceeds 2^{123}. - - Please note, this RNG is thread safe if used within OpenMP - directives, i.e., its state will be consistent while called from - multiple threads. However, the KISS generator does not create - random numbers in parallel from multiple sources, but in sequence - from a single source. If an OpenMP-enabled application heavily - relies on random numbers, one should consider employing a dedicated - parallel random number generator instead. - -_Standard_: - Fortran 95 and later - -_Class_: - Subroutine - -_Syntax_: - 'RANDOM_NUMBER(HARVEST)' - -_Arguments_: - HARVEST Shall be a scalar or an array of type 'REAL'. - -_Example_: - program test_random_number - REAL :: r(5,5) - CALL init_random_seed() ! see example of RANDOM_SEED - CALL RANDOM_NUMBER(r) - end program - -_See also_: - *note RANDOM_SEED:: - - -File: gfortran.info, Node: RANDOM_SEED, Next: RANGE, Prev: RANDOM_NUMBER, Up: Intrinsic Procedures - -8.201 'RANDOM_SEED' -- Initialize a pseudo-random number sequence -================================================================= - -_Description_: - Restarts or queries the state of the pseudorandom number generator - used by 'RANDOM_NUMBER'. - - If 'RANDOM_SEED' is called without arguments, it is initialized to - a default state. The example below shows how to initialize the - random seed with a varying seed in order to ensure a different - random number sequence for each invocation of the program. Note - that setting any of the seed values to zero should be avoided as it - can result in poor quality random numbers being generated. - -_Standard_: - Fortran 95 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL RANDOM_SEED([SIZE, PUT, GET])' - -_Arguments_: - SIZE (Optional) Shall be a scalar and of type default - 'INTEGER', with 'INTENT(OUT)'. It specifies the - minimum size of the arrays used with the PUT and - GET arguments. - PUT (Optional) Shall be an array of type default - 'INTEGER' and rank one. It is 'INTENT(IN)' and - the size of the array must be larger than or - equal to the number returned by the SIZE - argument. - GET (Optional) Shall be an array of type default - 'INTEGER' and rank one. It is 'INTENT(OUT)' and - the size of the array must be larger than or - equal to the number returned by the SIZE - argument. - -_Example_: - subroutine init_random_seed() - use iso_fortran_env, only: int64 - implicit none - integer, allocatable :: seed(:) - integer :: i, n, un, istat, dt(8), pid - integer(int64) :: t - - call random_seed(size = n) - allocate(seed(n)) - ! First try if the OS provides a random number generator - open(newunit=un, file="/dev/urandom", access="stream", & - form="unformatted", action="read", status="old", iostat=istat) - if (istat == 0) then - read(un) seed - close(un) - else - ! Fallback to XOR:ing the current time and pid. The PID is - ! useful in case one launches multiple instances of the same - ! program in parallel. - call system_clock(t) - if (t == 0) then - call date_and_time(values=dt) - t = (dt(1) - 1970) * 365_int64 * 24 * 60 * 60 * 1000 & - + dt(2) * 31_int64 * 24 * 60 * 60 * 1000 & - + dt(3) * 24_int64 * 60 * 60 * 1000 & - + dt(5) * 60 * 60 * 1000 & - + dt(6) * 60 * 1000 + dt(7) * 1000 & - + dt(8) - end if - pid = getpid() - t = ieor(t, int(pid, kind(t))) - do i = 1, n - seed(i) = lcg(t) - end do - end if - call random_seed(put=seed) - contains - ! This simple PRNG might not be good enough for real work, but is - ! sufficient for seeding a better PRNG. - function lcg(s) - integer :: lcg - integer(int64) :: s - if (s == 0) then - s = 104729 - else - s = mod(s, 4294967296_int64) - end if - s = mod(s * 279470273_int64, 4294967291_int64) - lcg = int(mod(s, int(huge(0), int64)), kind(0)) - end function lcg - end subroutine init_random_seed - -_See also_: - *note RANDOM_NUMBER:: - - -File: gfortran.info, Node: RANGE, Next: RANK, Prev: RANDOM_SEED, Up: Intrinsic Procedures - -8.202 'RANGE' -- Decimal exponent range -======================================= - -_Description_: - 'RANGE(X)' returns the decimal exponent range in the model of the - type of 'X'. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = RANGE(X)' - -_Arguments_: - X Shall be of type 'INTEGER', 'REAL' or 'COMPLEX'. - -_Return value_: - The return value is of type 'INTEGER' and of the default integer - kind. - -_See also_: - *note SELECTED_REAL_KIND::, *note PRECISION:: - -_Example_: - See 'PRECISION' for an example. - - -File: gfortran.info, Node: RANK, Next: REAL, Prev: RANGE, Up: Intrinsic Procedures - -8.203 'RANK' -- Rank of a data object -===================================== - -_Description_: - 'RANK(A)' returns the rank of a scalar or array data object. - -_Standard_: - Technical Specification (TS) 29113 - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = RANK(A)' - -_Arguments_: - A can be of any type - -_Return value_: - The return value is of type 'INTEGER' and of the default integer - kind. For arrays, their rank is returned; for scalars zero is - returned. - -_Example_: - program test_rank - integer :: a - real, allocatable :: b(:,:) - - print *, rank(a), rank(b) ! Prints: 0 2 - end program test_rank - - -File: gfortran.info, Node: REAL, Next: RENAME, Prev: RANK, Up: Intrinsic Procedures - -8.204 'REAL' -- Convert to real type -==================================== - -_Description_: - 'REAL(A [, KIND])' converts its argument A to a real type. The - 'REALPART' function is provided for compatibility with 'g77', and - its use is strongly discouraged. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = REAL(A [, KIND])' - 'RESULT = REALPART(Z)' - -_Arguments_: - A Shall be 'INTEGER', 'REAL', or 'COMPLEX'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - These functions return a 'REAL' variable or array under the - following rules: - - (A) - 'REAL(A)' is converted to a default real type if A is an - integer or real variable. - (B) - 'REAL(A)' is converted to a real type with the kind type - parameter of A if A is a complex variable. - (C) - 'REAL(A, KIND)' is converted to a real type with kind type - parameter KIND if A is a complex, integer, or real variable. - -_Example_: - program test_real - complex :: x = (1.0, 2.0) - print *, real(x), real(x,8), realpart(x) - end program test_real - -_Specific names_: - Name Argument Return type Standard - 'FLOAT(A)' 'INTEGER(4)' 'REAL(4)' Fortran 77 and - later - 'DFLOAT(A)' 'INTEGER(4)' 'REAL(8)' GNU extension - 'SNGL(A)' 'INTEGER(8)' 'REAL(4)' Fortran 77 and - later - -_See also_: - *note DBLE:: - - -File: gfortran.info, Node: RENAME, Next: REPEAT, Prev: REAL, Up: Intrinsic Procedures - -8.205 'RENAME' -- Rename a file -=============================== - -_Description_: - Renames a file from file PATH1 to PATH2. A null character - ('CHAR(0)') can be used to mark the end of the names in PATH1 and - PATH2; otherwise, trailing blanks in the file names are ignored. - If the STATUS argument is supplied, it contains 0 on success or a - nonzero error code upon return; see 'rename(2)'. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL RENAME(PATH1, PATH2 [, STATUS])' - 'STATUS = RENAME(PATH1, PATH2)' - -_Arguments_: - PATH1 Shall be of default 'CHARACTER' type. - PATH2 Shall be of default 'CHARACTER' type. - STATUS (Optional) Shall be of default 'INTEGER' type. - -_See also_: - *note LINK:: - - -File: gfortran.info, Node: REPEAT, Next: RESHAPE, Prev: RENAME, Up: Intrinsic Procedures - -8.206 'REPEAT' -- Repeated string concatenation -=============================================== - -_Description_: - Concatenates NCOPIES copies of a string. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = REPEAT(STRING, NCOPIES)' - -_Arguments_: - STRING Shall be scalar and of type 'CHARACTER'. - NCOPIES Shall be scalar and of type 'INTEGER'. - -_Return value_: - A new scalar of type 'CHARACTER' built up from NCOPIES copies of - STRING. - -_Example_: - program test_repeat - write(*,*) repeat("x", 5) ! "xxxxx" - end program - - -File: gfortran.info, Node: RESHAPE, Next: RRSPACING, Prev: REPEAT, Up: Intrinsic Procedures - -8.207 'RESHAPE' -- Function to reshape an array -=============================================== - -_Description_: - Reshapes SOURCE to correspond to SHAPE. If necessary, the new - array may be padded with elements from PAD or permuted as defined - by ORDER. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = RESHAPE(SOURCE, SHAPE[, PAD, ORDER])' - -_Arguments_: - SOURCE Shall be an array of any type. - SHAPE Shall be of type 'INTEGER' and an array of rank - one. Its values must be positive or zero. - PAD (Optional) shall be an array of the same type as - SOURCE. - ORDER (Optional) shall be of type 'INTEGER' and an - array of the same shape as SHAPE. Its values - shall be a permutation of the numbers from 1 to - n, where n is the size of SHAPE. If ORDER is - absent, the natural ordering shall be assumed. - -_Return value_: - The result is an array of shape SHAPE with the same type as SOURCE. - -_Example_: - PROGRAM test_reshape - INTEGER, DIMENSION(4) :: x - WRITE(*,*) SHAPE(x) ! prints "4" - WRITE(*,*) SHAPE(RESHAPE(x, (/2, 2/))) ! prints "2 2" - END PROGRAM - -_See also_: - *note SHAPE:: - - -File: gfortran.info, Node: RRSPACING, Next: RSHIFT, Prev: RESHAPE, Up: Intrinsic Procedures - -8.208 'RRSPACING' -- Reciprocal of the relative spacing -======================================================= - -_Description_: - 'RRSPACING(X)' returns the reciprocal of the relative spacing of - model numbers near X. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = RRSPACING(X)' - -_Arguments_: - X Shall be of type 'REAL'. - -_Return value_: - The return value is of the same type and kind as X. The value - returned is equal to 'ABS(FRACTION(X)) * - FLOAT(RADIX(X))**DIGITS(X)'. - -_See also_: - *note SPACING:: - - -File: gfortran.info, Node: RSHIFT, Next: SAME_TYPE_AS, Prev: RRSPACING, Up: Intrinsic Procedures - -8.209 'RSHIFT' -- Right shift bits -================================== - -_Description_: - 'RSHIFT' returns a value corresponding to I with all of the bits - shifted right by SHIFT places. If the absolute value of SHIFT is - greater than 'BIT_SIZE(I)', the value is undefined. Bits shifted - out from the right end are lost. The fill is arithmetic: the bits - shifted in from the left end are equal to the leftmost bit, which - in two's complement representation is the sign bit. - - This function has been superseded by the 'SHIFTA' intrinsic, which - is standard in Fortran 2008 and later. - -_Standard_: - GNU extension - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = RSHIFT(I, SHIFT)' - -_Arguments_: - I The type shall be 'INTEGER'. - SHIFT The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note ISHFT::, *note ISHFTC::, *note LSHIFT::, *note SHIFTA::, - *note SHIFTR::, *note SHIFTL:: - - -File: gfortran.info, Node: SAME_TYPE_AS, Next: SCALE, Prev: RSHIFT, Up: Intrinsic Procedures - -8.210 'SAME_TYPE_AS' -- Query dynamic types for equality -======================================================== - -_Description_: - Query dynamic types for equality. - -_Standard_: - Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = SAME_TYPE_AS(A, B)' - -_Arguments_: - A Shall be an object of extensible declared type - or unlimited polymorphic. - B Shall be an object of extensible declared type - or unlimited polymorphic. - -_Return value_: - The return value is a scalar of type default logical. It is true - if and only if the dynamic type of A is the same as the dynamic - type of B. - -_See also_: - *note EXTENDS_TYPE_OF:: - - -File: gfortran.info, Node: SCALE, Next: SCAN, Prev: SAME_TYPE_AS, Up: Intrinsic Procedures - -8.211 'SCALE' -- Scale a real value -=================================== - -_Description_: - 'SCALE(X,I)' returns 'X * RADIX(X)**I'. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SCALE(X, I)' - -_Arguments_: - X The type of the argument shall be a 'REAL'. - I The type of the argument shall be a 'INTEGER'. - -_Return value_: - The return value is of the same type and kind as X. Its value is - 'X * RADIX(X)**I'. - -_Example_: - program test_scale - real :: x = 178.1387e-4 - integer :: i = 5 - print *, scale(x,i), x*radix(x)**i - end program test_scale - - -File: gfortran.info, Node: SCAN, Next: SECNDS, Prev: SCALE, Up: Intrinsic Procedures - -8.212 'SCAN' -- Scan a string for the presence of a set of characters -===================================================================== - -_Description_: - Scans a STRING for any of the characters in a SET of characters. - - If BACK is either absent or equals 'FALSE', this function returns - the position of the leftmost character of STRING that is in SET. - If BACK equals 'TRUE', the rightmost position is returned. If no - character of SET is found in STRING, the result is zero. - -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SCAN(STRING, SET[, BACK [, KIND]])' - -_Arguments_: - STRING Shall be of type 'CHARACTER'. - SET Shall be of type 'CHARACTER'. - BACK (Optional) shall be of type 'LOGICAL'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. - -_Example_: - PROGRAM test_scan - WRITE(*,*) SCAN("FORTRAN", "AO") ! 2, found 'O' - WRITE(*,*) SCAN("FORTRAN", "AO", .TRUE.) ! 6, found 'A' - WRITE(*,*) SCAN("FORTRAN", "C++") ! 0, found none - END PROGRAM - -_See also_: - *note INDEX intrinsic::, *note VERIFY:: - - -File: gfortran.info, Node: SECNDS, Next: SECOND, Prev: SCAN, Up: Intrinsic Procedures - -8.213 'SECNDS' -- Time function -=============================== - -_Description_: - 'SECNDS(X)' gets the time in seconds from the real-time system - clock. X is a reference time, also in seconds. If this is zero, - the time in seconds from midnight is returned. This function is - non-standard and its use is discouraged. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = SECNDS (X)' - -_Arguments_: - T Shall be of type 'REAL(4)'. - X Shall be of type 'REAL(4)'. - -_Return value_: - None - -_Example_: - program test_secnds - integer :: i - real(4) :: t1, t2 - print *, secnds (0.0) ! seconds since midnight - t1 = secnds (0.0) ! reference time - do i = 1, 10000000 ! do something - end do - t2 = secnds (t1) ! elapsed time - print *, "Something took ", t2, " seconds." - end program test_secnds - - -File: gfortran.info, Node: SECOND, Next: SELECTED_CHAR_KIND, Prev: SECNDS, Up: Intrinsic Procedures - -8.214 'SECOND' -- CPU time function -=================================== - -_Description_: - Returns a 'REAL(4)' value representing the elapsed CPU time in - seconds. This provides the same functionality as the standard - 'CPU_TIME' intrinsic, and is only included for backwards - compatibility. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL SECOND(TIME)' - 'TIME = SECOND()' - -_Arguments_: - TIME Shall be of type 'REAL(4)'. - -_Return value_: - In either syntax, TIME is set to the process's current runtime in - seconds. - -_See also_: - *note CPU_TIME:: - - -File: gfortran.info, Node: SELECTED_CHAR_KIND, Next: SELECTED_INT_KIND, Prev: SECOND, Up: Intrinsic Procedures - -8.215 'SELECTED_CHAR_KIND' -- Choose character kind -=================================================== - -_Description_: - - 'SELECTED_CHAR_KIND(NAME)' returns the kind value for the character - set named NAME, if a character set with such a name is supported, - or -1 otherwise. Currently, supported character sets include - "ASCII" and "DEFAULT", which are equivalent, and "ISO_10646" - (Universal Character Set, UCS-4) which is commonly known as - Unicode. - -_Standard_: - Fortran 2003 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = SELECTED_CHAR_KIND(NAME)' - -_Arguments_: - NAME Shall be a scalar and of the default character - type. - -_Example_: - program character_kind - use iso_fortran_env - implicit none - integer, parameter :: ascii = selected_char_kind ("ascii") - integer, parameter :: ucs4 = selected_char_kind ('ISO_10646') - - character(kind=ascii, len=26) :: alphabet - character(kind=ucs4, len=30) :: hello_world - - alphabet = ascii_"abcdefghijklmnopqrstuvwxyz" - hello_world = ucs4_'Hello World and Ni Hao -- ' & - // char (int (z'4F60'), ucs4) & - // char (int (z'597D'), ucs4) - - write (*,*) alphabet - - open (output_unit, encoding='UTF-8') - write (*,*) trim (hello_world) - end program character_kind - - -File: gfortran.info, Node: SELECTED_INT_KIND, Next: SELECTED_REAL_KIND, Prev: SELECTED_CHAR_KIND, Up: Intrinsic Procedures - -8.216 'SELECTED_INT_KIND' -- Choose integer kind -================================================ - -_Description_: - 'SELECTED_INT_KIND(R)' return the kind value of the smallest - integer type that can represent all values ranging from -10^R - (exclusive) to 10^R (exclusive). If there is no integer kind that - accommodates this range, 'SELECTED_INT_KIND' returns -1. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = SELECTED_INT_KIND(R)' - -_Arguments_: - R Shall be a scalar and of type 'INTEGER'. - -_Example_: - program large_integers - integer,parameter :: k5 = selected_int_kind(5) - integer,parameter :: k15 = selected_int_kind(15) - integer(kind=k5) :: i5 - integer(kind=k15) :: i15 - - print *, huge(i5), huge(i15) - - ! The following inequalities are always true - print *, huge(i5) >= 10_k5**5-1 - print *, huge(i15) >= 10_k15**15-1 - end program large_integers - - -File: gfortran.info, Node: SELECTED_REAL_KIND, Next: SET_EXPONENT, Prev: SELECTED_INT_KIND, Up: Intrinsic Procedures - -8.217 'SELECTED_REAL_KIND' -- Choose real kind -============================================== - -_Description_: - 'SELECTED_REAL_KIND(P,R)' returns the kind value of a real data - type with decimal precision of at least 'P' digits, exponent range - of at least 'R', and with a radix of 'RADIX'. - -_Standard_: - Fortran 95 and later, with 'RADIX' Fortran 2008 or later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = SELECTED_REAL_KIND([P, R, RADIX])' - -_Arguments_: - P (Optional) shall be a scalar and of type - 'INTEGER'. - R (Optional) shall be a scalar and of type - 'INTEGER'. - RADIX (Optional) shall be a scalar and of type - 'INTEGER'. - Before Fortran 2008, at least one of the arguments R or P shall be - present; since Fortran 2008, they are assumed to be zero if absent. - -_Return value_: - - 'SELECTED_REAL_KIND' returns the value of the kind type parameter - of a real data type with decimal precision of at least 'P' digits, - a decimal exponent range of at least 'R', and with the requested - 'RADIX'. If the 'RADIX' parameter is absent, real kinds with any - radix can be returned. If more than one real data type meet the - criteria, the kind of the data type with the smallest decimal - precision is returned. If no real data type matches the criteria, - the result is - -1 if the processor does not support a real data type with a - precision greater than or equal to 'P', but the 'R' and - 'RADIX' requirements can be fulfilled - -2 if the processor does not support a real type with an exponent - range greater than or equal to 'R', but 'P' and 'RADIX' are - fulfillable - -3 if 'RADIX' but not 'P' and 'R' requirements - are fulfillable - -4 if 'RADIX' and either 'P' or 'R' requirements - are fulfillable - -5 if there is no real type with the given 'RADIX' - -_See also_: - *note PRECISION::, *note RANGE::, *note RADIX:: - -_Example_: - program real_kinds - integer,parameter :: p6 = selected_real_kind(6) - integer,parameter :: p10r100 = selected_real_kind(10,100) - integer,parameter :: r400 = selected_real_kind(r=400) - real(kind=p6) :: x - real(kind=p10r100) :: y - real(kind=r400) :: z - - print *, precision(x), range(x) - print *, precision(y), range(y) - print *, precision(z), range(z) - end program real_kinds - - -File: gfortran.info, Node: SET_EXPONENT, Next: SHAPE, Prev: SELECTED_REAL_KIND, Up: Intrinsic Procedures - -8.218 'SET_EXPONENT' -- Set the exponent of the model -===================================================== - -_Description_: - 'SET_EXPONENT(X, I)' returns the real number whose fractional part - is that that of X and whose exponent part is I. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SET_EXPONENT(X, I)' - -_Arguments_: - X Shall be of type 'REAL'. - I Shall be of type 'INTEGER'. - -_Return value_: - The return value is of the same type and kind as X. The real - number whose fractional part is that that of X and whose exponent - part if I is returned; it is 'FRACTION(X) * RADIX(X)**I'. - -_Example_: - PROGRAM test_setexp - REAL :: x = 178.1387e-4 - INTEGER :: i = 17 - PRINT *, SET_EXPONENT(x, i), FRACTION(x) * RADIX(x)**i - END PROGRAM - - -File: gfortran.info, Node: SHAPE, Next: SHIFTA, Prev: SET_EXPONENT, Up: Intrinsic Procedures - -8.219 'SHAPE' -- Determine the shape of an array -================================================ - -_Description_: - Determines the shape of an array. - -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = SHAPE(SOURCE [, KIND])' - -_Arguments_: - SOURCE Shall be an array or scalar of any type. If - SOURCE is a pointer it must be associated and - allocatable arrays must be allocated. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - An 'INTEGER' array of rank one with as many elements as SOURCE has - dimensions. The elements of the resulting array correspond to the - extend of SOURCE along the respective dimensions. If SOURCE is a - scalar, the result is the rank one array of size zero. If KIND is - absent, the return value has the default integer kind otherwise the - specified kind. - -_Example_: - PROGRAM test_shape - INTEGER, DIMENSION(-1:1, -1:2) :: A - WRITE(*,*) SHAPE(A) ! (/ 3, 4 /) - WRITE(*,*) SIZE(SHAPE(42)) ! (/ /) - END PROGRAM - -_See also_: - *note RESHAPE::, *note SIZE:: - - -File: gfortran.info, Node: SHIFTA, Next: SHIFTL, Prev: SHAPE, Up: Intrinsic Procedures - -8.220 'SHIFTA' -- Right shift with fill -======================================= - -_Description_: - 'SHIFTA' returns a value corresponding to I with all of the bits - shifted right by SHIFT places. If the absolute value of SHIFT is - greater than 'BIT_SIZE(I)', the value is undefined. Bits shifted - out from the right end are lost. The fill is arithmetic: the bits - shifted in from the left end are equal to the leftmost bit, which - in two's complement representation is the sign bit. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SHIFTA(I, SHIFT)' - -_Arguments_: - I The type shall be 'INTEGER'. - SHIFT The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note SHIFTL::, *note SHIFTR:: - - -File: gfortran.info, Node: SHIFTL, Next: SHIFTR, Prev: SHIFTA, Up: Intrinsic Procedures - -8.221 'SHIFTL' -- Left shift -============================ - -_Description_: - 'SHIFTL' returns a value corresponding to I with all of the bits - shifted left by SHIFT places. If the absolute value of SHIFT is - greater than 'BIT_SIZE(I)', the value is undefined. Bits shifted - out from the left end are lost, and bits shifted in from the right - end are set to 0. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SHIFTL(I, SHIFT)' - -_Arguments_: - I The type shall be 'INTEGER'. - SHIFT The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note SHIFTA::, *note SHIFTR:: - - -File: gfortran.info, Node: SHIFTR, Next: SIGN, Prev: SHIFTL, Up: Intrinsic Procedures - -8.222 'SHIFTR' -- Right shift -============================= - -_Description_: - 'SHIFTR' returns a value corresponding to I with all of the bits - shifted right by SHIFT places. If the absolute value of SHIFT is - greater than 'BIT_SIZE(I)', the value is undefined. Bits shifted - out from the right end are lost, and bits shifted in from the left - end are set to 0. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SHIFTR(I, SHIFT)' - -_Arguments_: - I The type shall be 'INTEGER'. - SHIFT The type shall be 'INTEGER'. - -_Return value_: - The return value is of type 'INTEGER' and of the same kind as I. - -_See also_: - *note SHIFTA::, *note SHIFTL:: - - -File: gfortran.info, Node: SIGN, Next: SIGNAL, Prev: SHIFTR, Up: Intrinsic Procedures - -8.223 'SIGN' -- Sign copying function -===================================== - -_Description_: - 'SIGN(A,B)' returns the value of A with the sign of B. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SIGN(A, B)' - -_Arguments_: - A Shall be of type 'INTEGER' or 'REAL' - B Shall be of the same type and kind as A - -_Return value_: - The kind of the return value is that of A and B. If B\ge 0 then - the result is 'ABS(A)', else it is '-ABS(A)'. - -_Example_: - program test_sign - print *, sign(-12,1) - print *, sign(-12,0) - print *, sign(-12,-1) - - print *, sign(-12.,1.) - print *, sign(-12.,0.) - print *, sign(-12.,-1.) - end program test_sign - -_Specific names_: - Name Arguments Return type Standard - 'SIGN(A,B)' 'REAL(4) A, 'REAL(4)' f77, gnu - B' - 'ISIGN(A,B)' 'INTEGER(4) 'INTEGER(4)' f77, gnu - A, B' - 'DSIGN(A,B)' 'REAL(8) A, 'REAL(8)' f77, gnu - B' - - -File: gfortran.info, Node: SIGNAL, Next: SIN, Prev: SIGN, Up: Intrinsic Procedures - -8.224 'SIGNAL' -- Signal handling subroutine (or function) -========================================================== - -_Description_: - 'SIGNAL(NUMBER, HANDLER [, STATUS])' causes external subroutine - HANDLER to be executed with a single integer argument when signal - NUMBER occurs. If HANDLER is an integer, it can be used to turn - off handling of signal NUMBER or revert to its default action. See - 'signal(2)'. - - If 'SIGNAL' is called as a subroutine and the STATUS argument is - supplied, it is set to the value returned by 'signal(2)'. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL SIGNAL(NUMBER, HANDLER [, STATUS])' - 'STATUS = SIGNAL(NUMBER, HANDLER)' - -_Arguments_: - NUMBER Shall be a scalar integer, with 'INTENT(IN)' - HANDLER Signal handler ('INTEGER FUNCTION' or - 'SUBROUTINE') or dummy/global 'INTEGER' scalar. - 'INTEGER'. It is 'INTENT(IN)'. - STATUS (Optional) STATUS shall be a scalar integer. It - has 'INTENT(OUT)'. - -_Return value_: - The 'SIGNAL' function returns the value returned by 'signal(2)'. - -_Example_: - program test_signal - intrinsic signal - external handler_print - - call signal (12, handler_print) - call signal (10, 1) - - call sleep (30) - end program test_signal - - -File: gfortran.info, Node: SIN, Next: SINH, Prev: SIGNAL, Up: Intrinsic Procedures - -8.225 'SIN' -- Sine function -============================ - -_Description_: - 'SIN(X)' computes the sine of X. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SIN(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value has same type and kind as X. - -_Example_: - program test_sin - real :: x = 0.0 - x = sin(x) - end program test_sin - -_Specific names_: - Name Argument Return type Standard - 'SIN(X)' 'REAL(4) X' 'REAL(4)' f77, gnu - 'DSIN(X)' 'REAL(8) X' 'REAL(8)' f95, gnu - 'CSIN(X)' 'COMPLEX(4) 'COMPLEX(4)' f95, gnu - X' - 'ZSIN(X)' 'COMPLEX(8) 'COMPLEX(8)' f95, gnu - X' - 'CDSIN(X)' 'COMPLEX(8) 'COMPLEX(8)' f95, gnu - X' - -_See also_: - *note ASIN:: - - -File: gfortran.info, Node: SINH, Next: SIZE, Prev: SIN, Up: Intrinsic Procedures - -8.226 'SINH' -- Hyperbolic sine function -======================================== - -_Description_: - 'SINH(X)' computes the hyperbolic sine of X. - -_Standard_: - Fortran 95 and later, for a complex argument Fortran 2008 or later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SINH(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value has same type and kind as X. - -_Example_: - program test_sinh - real(8) :: x = - 1.0_8 - x = sinh(x) - end program test_sinh - -_Specific names_: - Name Argument Return type Standard - 'SINH(X)' 'REAL(4) X' 'REAL(4)' Fortran 95 and - later - 'DSINH(X)' 'REAL(8) X' 'REAL(8)' Fortran 95 and - later - -_See also_: - *note ASINH:: - - -File: gfortran.info, Node: SIZE, Next: SIZEOF, Prev: SINH, Up: Intrinsic Procedures - -8.227 'SIZE' -- Determine the size of an array -============================================== - -_Description_: - Determine the extent of ARRAY along a specified dimension DIM, or - the total number of elements in ARRAY if DIM is absent. - -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = SIZE(ARRAY[, DIM [, KIND]])' - -_Arguments_: - ARRAY Shall be an array of any type. If ARRAY is a - pointer it must be associated and allocatable - arrays must be allocated. - DIM (Optional) shall be a scalar of type 'INTEGER' - and its value shall be in the range from 1 to n, - where n equals the rank of ARRAY. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. - -_Example_: - PROGRAM test_size - WRITE(*,*) SIZE((/ 1, 2 /)) ! 2 - END PROGRAM - -_See also_: - *note SHAPE::, *note RESHAPE:: - - -File: gfortran.info, Node: SIZEOF, Next: SLEEP, Prev: SIZE, Up: Intrinsic Procedures - -8.228 'SIZEOF' -- Size in bytes of an expression -================================================ - -_Description_: - 'SIZEOF(X)' calculates the number of bytes of storage the - expression 'X' occupies. - -_Standard_: - GNU extension - -_Class_: - Inquiry function - -_Syntax_: - 'N = SIZEOF(X)' - -_Arguments_: - X The argument shall be of any type, rank or - shape. - -_Return value_: - The return value is of type integer and of the system-dependent - kind C_SIZE_T (from the ISO_C_BINDING module). Its value is the - number of bytes occupied by the argument. If the argument has the - 'POINTER' attribute, the number of bytes of the storage area - pointed to is returned. If the argument is of a derived type with - 'POINTER' or 'ALLOCATABLE' components, the return value does not - account for the sizes of the data pointed to by these components. - If the argument is polymorphic, the size according to the declared - type is returned. The argument may not be a procedure or procedure - pointer. - -_Example_: - integer :: i - real :: r, s(5) - print *, (sizeof(s)/sizeof(r) == 5) - end - The example will print '.TRUE.' unless you are using a platform - where default 'REAL' variables are unusually padded. - -_See also_: - *note C_SIZEOF::, *note STORAGE_SIZE:: - - -File: gfortran.info, Node: SLEEP, Next: SPACING, Prev: SIZEOF, Up: Intrinsic Procedures - -8.229 'SLEEP' -- Sleep for the specified number of seconds -========================================================== - -_Description_: - Calling this subroutine causes the process to pause for SECONDS - seconds. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL SLEEP(SECONDS)' - -_Arguments_: - SECONDS The type shall be of default 'INTEGER'. - -_Example_: - program test_sleep - call sleep(5) - end - - -File: gfortran.info, Node: SPACING, Next: SPREAD, Prev: SLEEP, Up: Intrinsic Procedures - -8.230 'SPACING' -- Smallest distance between two numbers of a given type -======================================================================== - -_Description_: - Determines the distance between the argument X and the nearest - adjacent number of the same type. - -_Standard_: - Fortran 95 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SPACING(X)' - -_Arguments_: - X Shall be of type 'REAL'. - -_Return value_: - The result is of the same type as the input argument X. - -_Example_: - PROGRAM test_spacing - INTEGER, PARAMETER :: SGL = SELECTED_REAL_KIND(p=6, r=37) - INTEGER, PARAMETER :: DBL = SELECTED_REAL_KIND(p=13, r=200) - - WRITE(*,*) spacing(1.0_SGL) ! "1.1920929E-07" on i686 - WRITE(*,*) spacing(1.0_DBL) ! "2.220446049250313E-016" on i686 - END PROGRAM - -_See also_: - *note RRSPACING:: - - -File: gfortran.info, Node: SPREAD, Next: SQRT, Prev: SPACING, Up: Intrinsic Procedures - -8.231 'SPREAD' -- Add a dimension to an array -============================================= - -_Description_: - Replicates a SOURCE array NCOPIES times along a specified dimension - DIM. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = SPREAD(SOURCE, DIM, NCOPIES)' - -_Arguments_: - SOURCE Shall be a scalar or an array of any type and a - rank less than seven. - DIM Shall be a scalar of type 'INTEGER' with a value - in the range from 1 to n+1, where n equals the - rank of SOURCE. - NCOPIES Shall be a scalar of type 'INTEGER'. - -_Return value_: - The result is an array of the same type as SOURCE and has rank n+1 - where n equals the rank of SOURCE. - -_Example_: - PROGRAM test_spread - INTEGER :: a = 1, b(2) = (/ 1, 2 /) - WRITE(*,*) SPREAD(A, 1, 2) ! "1 1" - WRITE(*,*) SPREAD(B, 1, 2) ! "1 1 2 2" - END PROGRAM - -_See also_: - *note UNPACK:: - - -File: gfortran.info, Node: SQRT, Next: SRAND, Prev: SPREAD, Up: Intrinsic Procedures - -8.232 'SQRT' -- Square-root function -==================================== - -_Description_: - 'SQRT(X)' computes the square root of X. - -_Standard_: - Fortran 77 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = SQRT(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value is of type 'REAL' or 'COMPLEX'. The kind type - parameter is the same as X. - -_Example_: - program test_sqrt - real(8) :: x = 2.0_8 - complex :: z = (1.0, 2.0) - x = sqrt(x) - z = sqrt(z) - end program test_sqrt - -_Specific names_: - Name Argument Return type Standard - 'SQRT(X)' 'REAL(4) X' 'REAL(4)' Fortran 95 and - later - 'DSQRT(X)' 'REAL(8) X' 'REAL(8)' Fortran 95 and - later - 'CSQRT(X)' 'COMPLEX(4) 'COMPLEX(4)' Fortran 95 and - X' later - 'ZSQRT(X)' 'COMPLEX(8) 'COMPLEX(8)' GNU extension - X' - 'CDSQRT(X)' 'COMPLEX(8) 'COMPLEX(8)' GNU extension - X' - - -File: gfortran.info, Node: SRAND, Next: STAT, Prev: SQRT, Up: Intrinsic Procedures - -8.233 'SRAND' -- Reinitialize the random number generator -========================================================= - -_Description_: - 'SRAND' reinitializes the pseudo-random number generator called by - 'RAND' and 'IRAND'. The new seed used by the generator is - specified by the required argument SEED. - -_Standard_: - GNU extension - -_Class_: - Subroutine - -_Syntax_: - 'CALL SRAND(SEED)' - -_Arguments_: - SEED Shall be a scalar 'INTEGER(kind=4)'. - -_Return value_: - Does not return anything. - -_Example_: - See 'RAND' and 'IRAND' for examples. - -_Notes_: - The Fortran 2003 standard specifies the intrinsic 'RANDOM_SEED' to - initialize the pseudo-random numbers generator and 'RANDOM_NUMBER' - to generate pseudo-random numbers. Please note that in GNU - Fortran, these two sets of intrinsics ('RAND', 'IRAND' and 'SRAND' - on the one hand, 'RANDOM_NUMBER' and 'RANDOM_SEED' on the other - hand) access two independent pseudo-random number generators. - -_See also_: - *note RAND::, *note RANDOM_SEED::, *note RANDOM_NUMBER:: - - -File: gfortran.info, Node: STAT, Next: STORAGE_SIZE, Prev: SRAND, Up: Intrinsic Procedures - -8.234 'STAT' -- Get file status -=============================== - -_Description_: - This function returns information about a file. No permissions are - required on the file itself, but execute (search) permission is - required on all of the directories in path that lead to the file. - - The elements that are obtained and stored in the array 'VALUES': - 'VALUES(1)' Device ID - 'VALUES(2)' Inode number - 'VALUES(3)' File mode - 'VALUES(4)' Number of links - 'VALUES(5)' Owner's uid - 'VALUES(6)' Owner's gid - 'VALUES(7)' ID of device containing directory entry for file - (0 if not available) - 'VALUES(8)' File size (bytes) - 'VALUES(9)' Last access time - 'VALUES(10)'Last modification time - 'VALUES(11)'Last file status change time - 'VALUES(12)'Preferred I/O block size (-1 if not available) - 'VALUES(13)'Number of blocks allocated (-1 if not available) - - Not all these elements are relevant on all systems. If an element - is not relevant, it is returned as 0. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL STAT(NAME, VALUES [, STATUS])' - 'STATUS = STAT(NAME, VALUES)' - -_Arguments_: - NAME The type shall be 'CHARACTER', of the default - kind and a valid path within the file system. - VALUES The type shall be 'INTEGER(4), DIMENSION(13)'. - STATUS (Optional) status flag of type 'INTEGER(4)'. - Returns 0 on success and a system specific error - code otherwise. - -_Example_: - PROGRAM test_stat - INTEGER, DIMENSION(13) :: buff - INTEGER :: status - - CALL STAT("/etc/passwd", buff, status) - - IF (status == 0) THEN - WRITE (*, FMT="('Device ID:', T30, I19)") buff(1) - WRITE (*, FMT="('Inode number:', T30, I19)") buff(2) - WRITE (*, FMT="('File mode (octal):', T30, O19)") buff(3) - WRITE (*, FMT="('Number of links:', T30, I19)") buff(4) - WRITE (*, FMT="('Owner''s uid:', T30, I19)") buff(5) - WRITE (*, FMT="('Owner''s gid:', T30, I19)") buff(6) - WRITE (*, FMT="('Device where located:', T30, I19)") buff(7) - WRITE (*, FMT="('File size:', T30, I19)") buff(8) - WRITE (*, FMT="('Last access time:', T30, A19)") CTIME(buff(9)) - WRITE (*, FMT="('Last modification time', T30, A19)") CTIME(buff(10)) - WRITE (*, FMT="('Last status change time:', T30, A19)") CTIME(buff(11)) - WRITE (*, FMT="('Preferred block size:', T30, I19)") buff(12) - WRITE (*, FMT="('No. of blocks allocated:', T30, I19)") buff(13) - END IF - END PROGRAM - -_See also_: - To stat an open file: *note FSTAT::, to stat a link: *note LSTAT:: - - -File: gfortran.info, Node: STORAGE_SIZE, Next: SUM, Prev: STAT, Up: Intrinsic Procedures - -8.235 'STORAGE_SIZE' -- Storage size in bits -============================================ - -_Description_: - Returns the storage size of argument A in bits. -_Standard_: - Fortran 2008 and later -_Class_: - Inquiry function -_Syntax_: - 'RESULT = STORAGE_SIZE(A [, KIND])' - -_Arguments_: - A Shall be a scalar or array of any type. - KIND (Optional) shall be a scalar integer constant - expression. - -_Return Value_: - The result is a scalar integer with the kind type parameter - specified by KIND (or default integer type if KIND is missing). - The result value is the size expressed in bits for an element of an - array that has the dynamic type and type parameters of A. - -_See also_: - *note C_SIZEOF::, *note SIZEOF:: - - -File: gfortran.info, Node: SUM, Next: SYMLNK, Prev: STORAGE_SIZE, Up: Intrinsic Procedures - -8.236 'SUM' -- Sum of array elements -==================================== - -_Description_: - Adds the elements of ARRAY along dimension DIM if the corresponding - element in MASK is 'TRUE'. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = SUM(ARRAY[, MASK])' - 'RESULT = SUM(ARRAY, DIM[, MASK])' - -_Arguments_: - ARRAY Shall be an array of type 'INTEGER', 'REAL' or - 'COMPLEX'. - DIM (Optional) shall be a scalar of type 'INTEGER' - with a value in the range from 1 to n, where n - equals the rank of ARRAY. - MASK (Optional) shall be of type 'LOGICAL' and either - be a scalar or an array of the same shape as - ARRAY. - -_Return value_: - The result is of the same type as ARRAY. - - If DIM is absent, a scalar with the sum of all elements in ARRAY is - returned. Otherwise, an array of rank n-1, where n equals the rank - of ARRAY, and a shape similar to that of ARRAY with dimension DIM - dropped is returned. - -_Example_: - PROGRAM test_sum - INTEGER :: x(5) = (/ 1, 2, 3, 4 ,5 /) - print *, SUM(x) ! all elements, sum = 15 - print *, SUM(x, MASK=MOD(x, 2)==1) ! odd elements, sum = 9 - END PROGRAM - -_See also_: - *note PRODUCT:: - - -File: gfortran.info, Node: SYMLNK, Next: SYSTEM, Prev: SUM, Up: Intrinsic Procedures - -8.237 'SYMLNK' -- Create a symbolic link -======================================== - -_Description_: - Makes a symbolic link from file PATH1 to PATH2. A null character - ('CHAR(0)') can be used to mark the end of the names in PATH1 and - PATH2; otherwise, trailing blanks in the file names are ignored. - If the STATUS argument is supplied, it contains 0 on success or a - nonzero error code upon return; see 'symlink(2)'. If the system - does not supply 'symlink(2)', 'ENOSYS' is returned. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL SYMLNK(PATH1, PATH2 [, STATUS])' - 'STATUS = SYMLNK(PATH1, PATH2)' - -_Arguments_: - PATH1 Shall be of default 'CHARACTER' type. - PATH2 Shall be of default 'CHARACTER' type. - STATUS (Optional) Shall be of default 'INTEGER' type. - -_See also_: - *note LINK::, *note UNLINK:: - - -File: gfortran.info, Node: SYSTEM, Next: SYSTEM_CLOCK, Prev: SYMLNK, Up: Intrinsic Procedures - -8.238 'SYSTEM' -- Execute a shell command -========================================= - -_Description_: - Passes the command COMMAND to a shell (see 'system(3)'). If - argument STATUS is present, it contains the value returned by - 'system(3)', which is presumably 0 if the shell command succeeded. - Note that which shell is used to invoke the command is - system-dependent and environment-dependent. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - - Note that the 'system' function need not be thread-safe. It is the - responsibility of the user to ensure that 'system' is not called - concurrently. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL SYSTEM(COMMAND [, STATUS])' - 'STATUS = SYSTEM(COMMAND)' - -_Arguments_: - COMMAND Shall be of default 'CHARACTER' type. - STATUS (Optional) Shall be of default 'INTEGER' type. - -_See also_: - *note EXECUTE_COMMAND_LINE::, which is part of the Fortran 2008 - standard and should considered in new code for future portability. - - -File: gfortran.info, Node: SYSTEM_CLOCK, Next: TAN, Prev: SYSTEM, Up: Intrinsic Procedures - -8.239 'SYSTEM_CLOCK' -- Time function -===================================== - -_Description_: - Determines the COUNT of a processor clock since an unspecified time - in the past modulo COUNT_MAX, COUNT_RATE determines the number of - clock ticks per second. If the platform supports a monotonic - clock, that clock is used and can, depending on the platform clock - implementation, provide up to nanosecond resolution. If a - monotonic clock is not available, the implementation falls back to - a realtime clock. - - COUNT_RATE is system dependent and can vary depending on the kind - of the arguments. For KIND=4 arguments, COUNT represents - milliseconds, while for KIND=8 arguments, COUNT typically - represents micro- or nanoseconds depending on resolution of the - underlying platform clock. COUNT_MAX usually equals - 'HUGE(COUNT_MAX)'. Note that the millisecond resolution of the - KIND=4 version implies that the COUNT will wrap around in roughly - 25 days. In order to avoid issues with the wrap around and for - more precise timing, please use the KIND=8 version. - - If there is no clock, or querying the clock fails, COUNT is set to - '-HUGE(COUNT)', and COUNT_RATE and COUNT_MAX are set to zero. - - When running on a platform using the GNU C library (glibc) version - 2.16 or older, or a derivative thereof, the high resolution - monotonic clock is available only when linking with the RT library. - This can be done explicitly by adding the '-lrt' flag when linking - the application, but is also done implicitly when using OpenMP. - - On the Windows platform, the version with KIND=4 arguments uses the - 'GetTickCount' function, whereas the KIND=8 version uses - 'QueryPerformanceCounter' and 'QueryPerformanceCounterFrequency'. - For more information, and potential caveats, please see the - platform documentation. - -_Standard_: - Fortran 95 and later - -_Class_: - Subroutine - -_Syntax_: - 'CALL SYSTEM_CLOCK([COUNT, COUNT_RATE, COUNT_MAX])' - -_Arguments_: - COUNT (Optional) shall be a scalar of type 'INTEGER' - with 'INTENT(OUT)'. - COUNT_RATE (Optional) shall be a scalar of type 'INTEGER' - with 'INTENT(OUT)'. - COUNT_MAX (Optional) shall be a scalar of type 'INTEGER' - with 'INTENT(OUT)'. - -_Example_: - PROGRAM test_system_clock - INTEGER :: count, count_rate, count_max - CALL SYSTEM_CLOCK(count, count_rate, count_max) - WRITE(*,*) count, count_rate, count_max - END PROGRAM - -_See also_: - *note DATE_AND_TIME::, *note CPU_TIME:: - - -File: gfortran.info, Node: TAN, Next: TANH, Prev: SYSTEM_CLOCK, Up: Intrinsic Procedures - -8.240 'TAN' -- Tangent function -=============================== - -_Description_: - 'TAN(X)' computes the tangent of X. - -_Standard_: - Fortran 77 and later, for a complex argument Fortran 2008 or later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = TAN(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value has same type and kind as X. - -_Example_: - program test_tan - real(8) :: x = 0.165_8 - x = tan(x) - end program test_tan - -_Specific names_: - Name Argument Return type Standard - 'TAN(X)' 'REAL(4) X' 'REAL(4)' Fortran 95 and - later - 'DTAN(X)' 'REAL(8) X' 'REAL(8)' Fortran 95 and - later - -_See also_: - *note ATAN:: - - -File: gfortran.info, Node: TANH, Next: THIS_IMAGE, Prev: TAN, Up: Intrinsic Procedures - -8.241 'TANH' -- Hyperbolic tangent function -=========================================== - -_Description_: - 'TANH(X)' computes the hyperbolic tangent of X. - -_Standard_: - Fortran 77 and later, for a complex argument Fortran 2008 or later - -_Class_: - Elemental function - -_Syntax_: - 'X = TANH(X)' - -_Arguments_: - X The type shall be 'REAL' or 'COMPLEX'. - -_Return value_: - The return value has same type and kind as X. If X is complex, the - imaginary part of the result is in radians. If X is 'REAL', the - return value lies in the range - 1 \leq tanh(x) \leq 1 . - -_Example_: - program test_tanh - real(8) :: x = 2.1_8 - x = tanh(x) - end program test_tanh - -_Specific names_: - Name Argument Return type Standard - 'TANH(X)' 'REAL(4) X' 'REAL(4)' Fortran 95 and - later - 'DTANH(X)' 'REAL(8) X' 'REAL(8)' Fortran 95 and - later - -_See also_: - *note ATANH:: - - -File: gfortran.info, Node: THIS_IMAGE, Next: TIME, Prev: TANH, Up: Intrinsic Procedures - -8.242 'THIS_IMAGE' -- Function that returns the cosubscript index of this image -=============================================================================== - -_Description_: - Returns the cosubscript for this image. - -_Standard_: - Fortran 2008 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = THIS_IMAGE()' - 'RESULT = THIS_IMAGE(COARRAY [, DIM])' - -_Arguments_: - COARRAY Coarray of any type (optional; if DIM present, - required). - DIM default integer scalar (optional). If present, - DIM shall be between one and the corank of - COARRAY. - -_Return value_: - Default integer. If COARRAY is not present, it is scalar and its - value is the index of the invoking image. Otherwise, if DIM is not - present, a rank-1 array with corank elements is returned, - containing the cosubscripts for COARRAY specifying the invoking - image. If DIM is present, a scalar is returned, with the value of - the DIM element of 'THIS_IMAGE(COARRAY)'. - -_Example_: - INTEGER :: value[*] - INTEGER :: i - value = THIS_IMAGE() - SYNC ALL - IF (THIS_IMAGE() == 1) THEN - DO i = 1, NUM_IMAGES() - WRITE(*,'(2(a,i0))') 'value[', i, '] is ', value[i] - END DO - END IF - -_See also_: - *note NUM_IMAGES::, *note IMAGE_INDEX:: - - -File: gfortran.info, Node: TIME, Next: TIME8, Prev: THIS_IMAGE, Up: Intrinsic Procedures - -8.243 'TIME' -- Time function -============================= - -_Description_: - Returns the current time encoded as an integer (in the manner of - the function 'time(3)' in the C standard library). This value is - suitable for passing to 'CTIME', 'GMTIME', and 'LTIME'. - - This intrinsic is not fully portable, such as to systems with - 32-bit 'INTEGER' types but supporting times wider than 32 bits. - Therefore, the values returned by this intrinsic might be, or - become, negative, or numerically less than previous values, during - a single run of the compiled program. - - See *note TIME8::, for information on a similar intrinsic that - might be portable to more GNU Fortran implementations, though to - fewer Fortran compilers. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = TIME()' - -_Return value_: - The return value is a scalar of type 'INTEGER(4)'. - -_See also_: - *note CTIME::, *note GMTIME::, *note LTIME::, *note MCLOCK::, *note - TIME8:: - - -File: gfortran.info, Node: TIME8, Next: TINY, Prev: TIME, Up: Intrinsic Procedures - -8.244 'TIME8' -- Time function (64-bit) -======================================= - -_Description_: - Returns the current time encoded as an integer (in the manner of - the function 'time(3)' in the C standard library). This value is - suitable for passing to 'CTIME', 'GMTIME', and 'LTIME'. - - _Warning:_ this intrinsic does not increase the range of the timing - values over that returned by 'time(3)'. On a system with a 32-bit - 'time(3)', 'TIME8' will return a 32-bit value, even though it is - converted to a 64-bit 'INTEGER(8)' value. That means overflows of - the 32-bit value can still occur. Therefore, the values returned - by this intrinsic might be or become negative or numerically less - than previous values during a single run of the compiled program. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = TIME8()' - -_Return value_: - The return value is a scalar of type 'INTEGER(8)'. - -_See also_: - *note CTIME::, *note GMTIME::, *note LTIME::, *note MCLOCK8::, - *note TIME:: - - -File: gfortran.info, Node: TINY, Next: TRAILZ, Prev: TIME8, Up: Intrinsic Procedures - -8.245 'TINY' -- Smallest positive number of a real kind -======================================================= - -_Description_: - 'TINY(X)' returns the smallest positive (non zero) number in the - model of the type of 'X'. - -_Standard_: - Fortran 95 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = TINY(X)' - -_Arguments_: - X Shall be of type 'REAL'. - -_Return value_: - The return value is of the same type and kind as X - -_Example_: - See 'HUGE' for an example. - - -File: gfortran.info, Node: TRAILZ, Next: TRANSFER, Prev: TINY, Up: Intrinsic Procedures - -8.246 'TRAILZ' -- Number of trailing zero bits of an integer -============================================================ - -_Description_: - 'TRAILZ' returns the number of trailing zero bits of an integer. - -_Standard_: - Fortran 2008 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = TRAILZ(I)' - -_Arguments_: - I Shall be of type 'INTEGER'. - -_Return value_: - The type of the return value is the default 'INTEGER'. If all the - bits of 'I' are zero, the result value is 'BIT_SIZE(I)'. - -_Example_: - PROGRAM test_trailz - WRITE (*,*) TRAILZ(8) ! prints 3 - END PROGRAM - -_See also_: - *note BIT_SIZE::, *note LEADZ::, *note POPPAR::, *note POPCNT:: - - -File: gfortran.info, Node: TRANSFER, Next: TRANSPOSE, Prev: TRAILZ, Up: Intrinsic Procedures - -8.247 'TRANSFER' -- Transfer bit patterns -========================================= - -_Description_: - Interprets the bitwise representation of SOURCE in memory as if it - is the representation of a variable or array of the same type and - type parameters as MOLD. - - This is approximately equivalent to the C concept of _casting_ one - type to another. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = TRANSFER(SOURCE, MOLD[, SIZE])' - -_Arguments_: - SOURCE Shall be a scalar or an array of any type. - MOLD Shall be a scalar or an array of any type. - SIZE (Optional) shall be a scalar of type 'INTEGER'. - -_Return value_: - The result has the same type as MOLD, with the bit level - representation of SOURCE. If SIZE is present, the result is a - one-dimensional array of length SIZE. If SIZE is absent but MOLD - is an array (of any size or shape), the result is a one- - dimensional array of the minimum length needed to contain the - entirety of the bitwise representation of SOURCE. If SIZE is - absent and MOLD is a scalar, the result is a scalar. - - If the bitwise representation of the result is longer than that of - SOURCE, then the leading bits of the result correspond to those of - SOURCE and any trailing bits are filled arbitrarily. - - When the resulting bit representation does not correspond to a - valid representation of a variable of the same type as MOLD, the - results are undefined, and subsequent operations on the result - cannot be guaranteed to produce sensible behavior. For example, it - is possible to create 'LOGICAL' variables for which 'VAR' and - '.NOT.VAR' both appear to be true. - -_Example_: - PROGRAM test_transfer - integer :: x = 2143289344 - print *, transfer(x, 1.0) ! prints "NaN" on i686 - END PROGRAM - - -File: gfortran.info, Node: TRANSPOSE, Next: TRIM, Prev: TRANSFER, Up: Intrinsic Procedures - -8.248 'TRANSPOSE' -- Transpose an array of rank two -=================================================== - -_Description_: - Transpose an array of rank two. Element (i, j) of the result has - the value 'MATRIX(j, i)', for all i, j. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = TRANSPOSE(MATRIX)' - -_Arguments_: - MATRIX Shall be an array of any type and have a rank of - two. - -_Return value_: - The result has the same type as MATRIX, and has shape '(/ m, n /)' - if MATRIX has shape '(/ n, m /)'. - - -File: gfortran.info, Node: TRIM, Next: TTYNAM, Prev: TRANSPOSE, Up: Intrinsic Procedures - -8.249 'TRIM' -- Remove trailing blank characters of a string -============================================================ - -_Description_: - Removes trailing blank characters of a string. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = TRIM(STRING)' - -_Arguments_: - STRING Shall be a scalar of type 'CHARACTER'. - -_Return value_: - A scalar of type 'CHARACTER' which length is that of STRING less - the number of trailing blanks. - -_Example_: - PROGRAM test_trim - CHARACTER(len=10), PARAMETER :: s = "GFORTRAN " - WRITE(*,*) LEN(s), LEN(TRIM(s)) ! "10 8", with/without trailing blanks - END PROGRAM - -_See also_: - *note ADJUSTL::, *note ADJUSTR:: - - -File: gfortran.info, Node: TTYNAM, Next: UBOUND, Prev: TRIM, Up: Intrinsic Procedures - -8.250 'TTYNAM' -- Get the name of a terminal device. -==================================================== - -_Description_: - Get the name of a terminal device. For more information, see - 'ttyname(3)'. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL TTYNAM(UNIT, NAME)' - 'NAME = TTYNAM(UNIT)' - -_Arguments_: - UNIT Shall be a scalar 'INTEGER'. - NAME Shall be of type 'CHARACTER'. - -_Example_: - PROGRAM test_ttynam - INTEGER :: unit - DO unit = 1, 10 - IF (isatty(unit=unit)) write(*,*) ttynam(unit) - END DO - END PROGRAM - -_See also_: - *note ISATTY:: - - -File: gfortran.info, Node: UBOUND, Next: UCOBOUND, Prev: TTYNAM, Up: Intrinsic Procedures - -8.251 'UBOUND' -- Upper dimension bounds of an array -==================================================== - -_Description_: - Returns the upper bounds of an array, or a single upper bound along - the DIM dimension. -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = UBOUND(ARRAY [, DIM [, KIND]])' - -_Arguments_: - ARRAY Shall be an array, of any type. - DIM (Optional) Shall be a scalar 'INTEGER'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. If DIM is - absent, the result is an array of the upper bounds of ARRAY. If - DIM is present, the result is a scalar corresponding to the upper - bound of the array along that dimension. If ARRAY is an expression - rather than a whole array or array structure component, or if it - has a zero extent along the relevant dimension, the upper bound is - taken to be the number of elements along the relevant dimension. - -_See also_: - *note LBOUND::, *note LCOBOUND:: - - -File: gfortran.info, Node: UCOBOUND, Next: UMASK, Prev: UBOUND, Up: Intrinsic Procedures - -8.252 'UCOBOUND' -- Upper codimension bounds of an array -======================================================== - -_Description_: - Returns the upper cobounds of a coarray, or a single upper cobound - along the DIM codimension. -_Standard_: - Fortran 2008 and later - -_Class_: - Inquiry function - -_Syntax_: - 'RESULT = UCOBOUND(COARRAY [, DIM [, KIND]])' - -_Arguments_: - ARRAY Shall be an coarray, of any type. - DIM (Optional) Shall be a scalar 'INTEGER'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. If DIM is - absent, the result is an array of the lower cobounds of COARRAY. - If DIM is present, the result is a scalar corresponding to the - lower cobound of the array along that codimension. - -_See also_: - *note LCOBOUND::, *note LBOUND:: - - -File: gfortran.info, Node: UMASK, Next: UNLINK, Prev: UCOBOUND, Up: Intrinsic Procedures - -8.253 'UMASK' -- Set the file creation mask -=========================================== - -_Description_: - Sets the file creation mask to MASK. If called as a function, it - returns the old value. If called as a subroutine and argument OLD - if it is supplied, it is set to the old value. See 'umask(2)'. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL UMASK(MASK [, OLD])' - 'OLD = UMASK(MASK)' - -_Arguments_: - MASK Shall be a scalar of type 'INTEGER'. - OLD (Optional) Shall be a scalar of type 'INTEGER'. - - -File: gfortran.info, Node: UNLINK, Next: UNPACK, Prev: UMASK, Up: Intrinsic Procedures - -8.254 'UNLINK' -- Remove a file from the file system -==================================================== - -_Description_: - Unlinks the file PATH. A null character ('CHAR(0)') can be used to - mark the end of the name in PATH; otherwise, trailing blanks in the - file name are ignored. If the STATUS argument is supplied, it - contains 0 on success or a nonzero error code upon return; see - 'unlink(2)'. - - This intrinsic is provided in both subroutine and function forms; - however, only one form can be used in any given program unit. - -_Standard_: - GNU extension - -_Class_: - Subroutine, function - -_Syntax_: - 'CALL UNLINK(PATH [, STATUS])' - 'STATUS = UNLINK(PATH)' - -_Arguments_: - PATH Shall be of default 'CHARACTER' type. - STATUS (Optional) Shall be of default 'INTEGER' type. - -_See also_: - *note LINK::, *note SYMLNK:: - - -File: gfortran.info, Node: UNPACK, Next: VERIFY, Prev: UNLINK, Up: Intrinsic Procedures - -8.255 'UNPACK' -- Unpack an array of rank one into an array -=========================================================== - -_Description_: - Store the elements of VECTOR in an array of higher rank. - -_Standard_: - Fortran 95 and later - -_Class_: - Transformational function - -_Syntax_: - 'RESULT = UNPACK(VECTOR, MASK, FIELD)' - -_Arguments_: - VECTOR Shall be an array of any type and rank one. It - shall have at least as many elements as MASK has - 'TRUE' values. - MASK Shall be an array of type 'LOGICAL'. - FIELD Shall be of the same type as VECTOR and have the - same shape as MASK. - -_Return value_: - The resulting array corresponds to FIELD with 'TRUE' elements of - MASK replaced by values from VECTOR in array element order. - -_Example_: - PROGRAM test_unpack - integer :: vector(2) = (/1,1/) - logical :: mask(4) = (/ .TRUE., .FALSE., .FALSE., .TRUE. /) - integer :: field(2,2) = 0, unity(2,2) - - ! result: unity matrix - unity = unpack(vector, reshape(mask, (/2,2/)), field) - END PROGRAM - -_See also_: - *note PACK::, *note SPREAD:: - - -File: gfortran.info, Node: VERIFY, Next: XOR, Prev: UNPACK, Up: Intrinsic Procedures - -8.256 'VERIFY' -- Scan a string for characters not a given set -============================================================== - -_Description_: - Verifies that all the characters in STRING belong to the set of - characters in SET. - - If BACK is either absent or equals 'FALSE', this function returns - the position of the leftmost character of STRING that is not in - SET. If BACK equals 'TRUE', the rightmost position is returned. - If all characters of STRING are found in SET, the result is zero. - -_Standard_: - Fortran 95 and later, with KIND argument Fortran 2003 and later - -_Class_: - Elemental function - -_Syntax_: - 'RESULT = VERIFY(STRING, SET[, BACK [, KIND]])' - -_Arguments_: - STRING Shall be of type 'CHARACTER'. - SET Shall be of type 'CHARACTER'. - BACK (Optional) shall be of type 'LOGICAL'. - KIND (Optional) An 'INTEGER' initialization - expression indicating the kind parameter of the - result. - -_Return value_: - The return value is of type 'INTEGER' and of kind KIND. If KIND is - absent, the return value is of default integer kind. - -_Example_: - PROGRAM test_verify - WRITE(*,*) VERIFY("FORTRAN", "AO") ! 1, found 'F' - WRITE(*,*) VERIFY("FORTRAN", "FOO") ! 3, found 'R' - WRITE(*,*) VERIFY("FORTRAN", "C++") ! 1, found 'F' - WRITE(*,*) VERIFY("FORTRAN", "C++", .TRUE.) ! 7, found 'N' - WRITE(*,*) VERIFY("FORTRAN", "FORTRAN") ! 0' found none - END PROGRAM - -_See also_: - *note SCAN::, *note INDEX intrinsic:: - - -File: gfortran.info, Node: XOR, Prev: VERIFY, Up: Intrinsic Procedures - -8.257 'XOR' -- Bitwise logical exclusive OR -=========================================== - -_Description_: - Bitwise logical exclusive or. - - This intrinsic routine is provided for backwards compatibility with - GNU Fortran 77. For integer arguments, programmers should consider - the use of the *note IEOR:: intrinsic and for logical arguments the - '.NEQV.' operator, which are both defined by the Fortran standard. - -_Standard_: - GNU extension - -_Class_: - Function - -_Syntax_: - 'RESULT = XOR(I, J)' - -_Arguments_: - I The type shall be either a scalar 'INTEGER' type - or a scalar 'LOGICAL' type. - J The type shall be the same as the type of I. - -_Return value_: - The return type is either a scalar 'INTEGER' or a scalar 'LOGICAL'. - If the kind type parameters differ, then the smaller kind type is - implicitly converted to larger kind, and the return has the larger - kind. - -_Example_: - PROGRAM test_xor - LOGICAL :: T = .TRUE., F = .FALSE. - INTEGER :: a, b - DATA a / Z'F' /, b / Z'3' / - - WRITE (*,*) XOR(T, T), XOR(T, F), XOR(F, T), XOR(F, F) - WRITE (*,*) XOR(a, b) - END PROGRAM - -_See also_: - Fortran 95 elemental function: *note IEOR:: - - -File: gfortran.info, Node: Intrinsic Modules, Next: Contributing, Prev: Intrinsic Procedures, Up: Top - -9 Intrinsic Modules -******************* - -* Menu: - -* ISO_FORTRAN_ENV:: -* ISO_C_BINDING:: -* OpenMP Modules OMP_LIB and OMP_LIB_KINDS:: - - -File: gfortran.info, Node: ISO_FORTRAN_ENV, Next: ISO_C_BINDING, Up: Intrinsic Modules - -9.1 'ISO_FORTRAN_ENV' -===================== - -_Standard_: - Fortran 2003 and later, except when otherwise noted - - The 'ISO_FORTRAN_ENV' module provides the following scalar -default-integer named constants: - -'ATOMIC_INT_KIND': - Default-kind integer constant to be used as kind parameter when - defining integer variables used in atomic operations. (Fortran - 2008 or later.) - -'ATOMIC_LOGICAL_KIND': - Default-kind integer constant to be used as kind parameter when - defining logical variables used in atomic operations. (Fortran - 2008 or later.) - -'CHARACTER_KINDS': - Default-kind integer constant array of rank one containing the - supported kind parameters of the 'CHARACTER' type. (Fortran 2008 - or later.) - -'CHARACTER_STORAGE_SIZE': - Size in bits of the character storage unit. - -'ERROR_UNIT': - Identifies the preconnected unit used for error reporting. - -'FILE_STORAGE_SIZE': - Size in bits of the file-storage unit. - -'INPUT_UNIT': - Identifies the preconnected unit identified by the asterisk ('*') - in 'READ' statement. - -'INT8', 'INT16', 'INT32', 'INT64': - Kind type parameters to specify an INTEGER type with a storage size - of 16, 32, and 64 bits. It is negative if a target platform does - not support the particular kind. (Fortran 2008 or later.) - -'INTEGER_KINDS': - Default-kind integer constant array of rank one containing the - supported kind parameters of the 'INTEGER' type. (Fortran 2008 or - later.) - -'IOSTAT_END': - The value assigned to the variable passed to the 'IOSTAT=' - specifier of an input/output statement if an end-of-file condition - occurred. - -'IOSTAT_EOR': - The value assigned to the variable passed to the 'IOSTAT=' - specifier of an input/output statement if an end-of-record - condition occurred. - -'IOSTAT_INQUIRE_INTERNAL_UNIT': - Scalar default-integer constant, used by 'INQUIRE' for the - 'IOSTAT=' specifier to denote an that a unit number identifies an - internal unit. (Fortran 2008 or later.) - -'NUMERIC_STORAGE_SIZE': - The size in bits of the numeric storage unit. - -'LOGICAL_KINDS': - Default-kind integer constant array of rank one containing the - supported kind parameters of the 'LOGICAL' type. (Fortran 2008 or - later.) - -'OUTPUT_UNIT': - Identifies the preconnected unit identified by the asterisk ('*') - in 'WRITE' statement. - -'REAL32', 'REAL64', 'REAL128': - Kind type parameters to specify a REAL type with a storage size of - 32, 64, and 128 bits. It is negative if a target platform does not - support the particular kind. (Fortran 2008 or later.) - -'REAL_KINDS': - Default-kind integer constant array of rank one containing the - supported kind parameters of the 'REAL' type. (Fortran 2008 or - later.) - -'STAT_LOCKED': - Scalar default-integer constant used as STAT= return value by - 'LOCK' to denote that the lock variable is locked by the executing - image. (Fortran 2008 or later.) - -'STAT_LOCKED_OTHER_IMAGE': - Scalar default-integer constant used as STAT= return value by - 'UNLOCK' to denote that the lock variable is locked by another - image. (Fortran 2008 or later.) - -'STAT_STOPPED_IMAGE': - Positive, scalar default-integer constant used as STAT= return - value if the argument in the statement requires synchronisation - with an image, which has initiated the termination of the - execution. (Fortran 2008 or later.) - -'STAT_UNLOCKED': - Scalar default-integer constant used as STAT= return value by - 'UNLOCK' to denote that the lock variable is unlocked. (Fortran - 2008 or later.) - - The module provides the following derived type: - -'LOCK_TYPE': - Derived type with private components to be use with the 'LOCK' and - 'UNLOCK' statement. A variable of its type has to be always - declared as coarray and may not appear in a variable-definition - context. (Fortran 2008 or later.) - - The module also provides the following intrinsic procedures: *note -COMPILER_OPTIONS:: and *note COMPILER_VERSION::. - - -File: gfortran.info, Node: ISO_C_BINDING, Next: OpenMP Modules OMP_LIB and OMP_LIB_KINDS, Prev: ISO_FORTRAN_ENV, Up: Intrinsic Modules - -9.2 'ISO_C_BINDING' -=================== - -_Standard_: - Fortran 2003 and later, GNU extensions - - The following intrinsic procedures are provided by the module; their -definition can be found in the section Intrinsic Procedures of this -manual. - -'C_ASSOCIATED' -'C_F_POINTER' -'C_F_PROCPOINTER' -'C_FUNLOC' -'C_LOC' -'C_SIZEOF' - - The 'ISO_C_BINDING' module provides the following named constants of -type default integer, which can be used as KIND type parameters. - - In addition to the integer named constants required by the Fortran -2003 standard and 'C_PTRDIFF_T' of TS 29113, GNU Fortran provides as an -extension named constants for the 128-bit integer types supported by the -C compiler: 'C_INT128_T, C_INT_LEAST128_T, C_INT_FAST128_T'. -Furthermore, if '__float128' is supported in C, the named constants -'C_FLOAT128, C_FLOAT128_COMPLEX' are defined. - -Fortran Named constant C type Extension -Type -'INTEGER' 'C_INT' 'int' -'INTEGER' 'C_SHORT' 'short int' -'INTEGER' 'C_LONG' 'long int' -'INTEGER' 'C_LONG_LONG' 'long long int' -'INTEGER' 'C_SIGNED_CHAR' 'signed char'/'unsigned - char' -'INTEGER' 'C_SIZE_T' 'size_t' -'INTEGER' 'C_INT8_T' 'int8_t' -'INTEGER' 'C_INT16_T' 'int16_t' -'INTEGER' 'C_INT32_T' 'int32_t' -'INTEGER' 'C_INT64_T' 'int64_t' -'INTEGER' 'C_INT128_T' 'int128_t' Ext. -'INTEGER' 'C_INT_LEAST8_T' 'int_least8_t' -'INTEGER' 'C_INT_LEAST16_T' 'int_least16_t' -'INTEGER' 'C_INT_LEAST32_T' 'int_least32_t' -'INTEGER' 'C_INT_LEAST64_T' 'int_least64_t' -'INTEGER' 'C_INT_LEAST128_T' 'int_least128_t' Ext. -'INTEGER' 'C_INT_FAST8_T' 'int_fast8_t' -'INTEGER' 'C_INT_FAST16_T' 'int_fast16_t' -'INTEGER' 'C_INT_FAST32_T' 'int_fast32_t' -'INTEGER' 'C_INT_FAST64_T' 'int_fast64_t' -'INTEGER' 'C_INT_FAST128_T' 'int_fast128_t' Ext. -'INTEGER' 'C_INTMAX_T' 'intmax_t' -'INTEGER' 'C_INTPTR_T' 'intptr_t' -'INTEGER' 'C_PTRDIFF_T' 'intptr_t' TS 29113 -'REAL' 'C_FLOAT' 'float' -'REAL' 'C_DOUBLE' 'double' -'REAL' 'C_LONG_DOUBLE' 'long double' -'REAL' 'C_FLOAT128' '__float128' Ext. -'COMPLEX' 'C_FLOAT_COMPLEX' 'float _Complex' -'COMPLEX' 'C_DOUBLE_COMPLEX' 'double _Complex' -'COMPLEX' 'C_LONG_DOUBLE_COMPLEX' 'long double _Complex' -'REAL' 'C_FLOAT128_COMPLEX' '__float128 _Complex' Ext. -'LOGICAL' 'C_BOOL' '_Bool' -'CHARACTER' 'C_CHAR' 'char' - - Additionally, the following parameters of type -'CHARACTER(KIND=C_CHAR)' are defined. - -Name C definition Value -'C_NULL_CHAR' null character ''\0'' -'C_ALERT' alert ''\a'' -'C_BACKSPACE' backspace ''\b'' -'C_FORM_FEED' form feed ''\f'' -'C_NEW_LINE' new line ''\n'' -'C_CARRIAGE_RETURN'carriage return ''\r'' -'C_HORIZONTAL_TAB'horizontal tab ''\t'' -'C_VERTICAL_TAB'vertical tab ''\v'' - - Moreover, the following two named constants are defined: - -Name Type -'C_NULL_PTR' 'C_PTR' -'C_NULL_FUNPTR''C_FUNPTR' - - Both are equivalent to the value 'NULL' in C. - - -File: gfortran.info, Node: OpenMP Modules OMP_LIB and OMP_LIB_KINDS, Prev: ISO_C_BINDING, Up: Intrinsic Modules - -9.3 OpenMP Modules 'OMP_LIB' and 'OMP_LIB_KINDS' -================================================ - -_Standard_: - OpenMP Application Program Interface v4.0 - - The OpenMP Fortran runtime library routines are provided both in a -form of two Fortran 90 modules, named 'OMP_LIB' and 'OMP_LIB_KINDS', and -in a form of a Fortran 'include' file named 'omp_lib.h'. The procedures -provided by 'OMP_LIB' can be found in the *note Introduction: -(libgomp)Top. manual, the named constants defined in the modules are -listed below. - - For details refer to the actual OpenMP Application Program Interface -v4.0 (http://www.openmp.org/mp-documents/OpenMP4.0.0.pdf). - - 'OMP_LIB_KINDS' provides the following scalar default-integer named -constants: - -'omp_lock_kind' -'omp_nest_lock_kind' -'omp_proc_bind_kind' -'omp_sched_kind' - - 'OMP_LIB' provides the scalar default-integer named constant -'openmp_version' with a value of the form YYYYMM, where 'yyyy' is the -year and MM the month of the OpenMP version; for OpenMP v3.1 the value -is '201107' and for OpenMP v4.0 the value is '201307'. - - The following scalar integer named constants of the kind -'omp_sched_kind': - -'omp_sched_static' -'omp_sched_dynamic' -'omp_sched_guided' -'omp_sched_auto' - - And the following scalar integer named constants of the kind -'omp_proc_bind_kind': - -'omp_proc_bind_false' -'omp_proc_bind_true' -'omp_proc_bind_master' -'omp_proc_bind_close' -'omp_proc_bind_spread' - - -File: gfortran.info, Node: Contributing, Next: Copying, Prev: Intrinsic Modules, Up: Top - -Contributing -************ - -Free software is only possible if people contribute to efforts to create -it. We're always in need of more people helping out with ideas and -comments, writing documentation and contributing code. - - If you want to contribute to GNU Fortran, have a look at the long -lists of projects you can take on. Some of these projects are small, -some of them are large; some are completely orthogonal to the rest of -what is happening on GNU Fortran, but others are "mainstream" projects -in need of enthusiastic hackers. All of these projects are important! -We will eventually get around to the things here, but they are also -things doable by someone who is willing and able. - -* Menu: - -* Contributors:: -* Projects:: -* Proposed Extensions:: - - -File: gfortran.info, Node: Contributors, Next: Projects, Up: Contributing - -Contributors to GNU Fortran -=========================== - -Most of the parser was hand-crafted by _Andy Vaught_, who is also the -initiator of the whole project. Thanks Andy! Most of the interface -with GCC was written by _Paul Brook_. - - The following individuals have contributed code and/or ideas and -significant help to the GNU Fortran project (in alphabetical order): - - - Janne Blomqvist - - Steven Bosscher - - Paul Brook - - Tobias Burnus - - Franc,ois-Xavier Coudert - - Bud Davis - - Jerry DeLisle - - Erik Edelmann - - Bernhard Fischer - - Daniel Franke - - Richard Guenther - - Richard Henderson - - Katherine Holcomb - - Jakub Jelinek - - Niels Kristian Bech Jensen - - Steven Johnson - - Steven G. Kargl - - Thomas Koenig - - Asher Langton - - H. J. Lu - - Toon Moene - - Brooks Moses - - Andrew Pinski - - Tim Prince - - Christopher D. Rickett - - Richard Sandiford - - Tobias Schlu"ter - - Roger Sayle - - Paul Thomas - - Andy Vaught - - Feng Wang - - Janus Weil - - Daniel Kraft - - The following people have contributed bug reports, smaller or larger -patches, and much needed feedback and encouragement for the GNU Fortran -project: - - - Bill Clodius - - Dominique d'Humie`res - - Kate Hedstrom - - Erik Schnetter - - Joost VandeVondele - - Many other individuals have helped debug, test and improve the GNU -Fortran compiler over the past few years, and we welcome you to do the -same! If you already have done so, and you would like to see your name -listed in the list above, please contact us. - - -File: gfortran.info, Node: Projects, Next: Proposed Extensions, Prev: Contributors, Up: Contributing - -Projects -======== - -_Help build the test suite_ - Solicit more code for donation to the test suite: the more - extensive the testsuite, the smaller the risk of breaking things in - the future! We can keep code private on request. - -_Bug hunting/squishing_ - Find bugs and write more test cases! Test cases are especially - very welcome, because it allows us to concentrate on fixing bugs - instead of isolating them. Going through the bugzilla database at - <http://gcc.gnu.org/bugzilla/> to reduce testcases posted there and - add more information (for example, for which version does the - testcase work, for which versions does it fail?) is also very - helpful. - - -File: gfortran.info, Node: Proposed Extensions, Prev: Projects, Up: Contributing - -Proposed Extensions -=================== - -Here's a list of proposed extensions for the GNU Fortran compiler, in no -particular order. Most of these are necessary to be fully compatible -with existing Fortran compilers, but they are not part of the official -J3 Fortran 95 standard. - -Compiler extensions: --------------------- - - * User-specified alignment rules for structures. - - * Automatically extend single precision constants to double. - - * Compile code that conserves memory by dynamically allocating common - and module storage either on stack or heap. - - * Compile flag to generate code for array conformance checking - (suggest -CC). - - * User control of symbol names (underscores, etc). - - * Compile setting for maximum size of stack frame size before - spilling parts to static or heap. - - * Flag to force local variables into static space. - - * Flag to force local variables onto stack. - -Environment Options -------------------- - - * Pluggable library modules for random numbers, linear algebra. 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Interpretation of Sections 15 and 16. - - If the disclaimer of warranty and limitation of liability provided - above cannot be given local legal effect according to their terms, - reviewing courts shall apply local law that most closely - approximates an absolute waiver of all civil liability in - connection with the Program, unless a warranty or assumption of - liability accompanies a copy of the Program in return for a fee. - -END OF TERMS AND CONDITIONS -=========================== - -How to Apply These Terms to Your New Programs -============================================= - -If you develop a new program, and you want it to be of the greatest -possible use to the public, the best way to achieve this is to make it -free software which everyone can redistribute and change under these -terms. - - To do so, attach the following notices to the program. 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If not, see <http://www.gnu.org/licenses/>. - - Also add information on how to contact you by electronic and paper -mail. - - If the program does terminal interaction, make it output a short -notice like this when it starts in an interactive mode: - - PROGRAM Copyright (C) YEAR NAME OF AUTHOR - This program comes with ABSOLUTELY NO WARRANTY; for details type 'show w'. - This is free software, and you are welcome to redistribute it - under certain conditions; type 'show c' for details. - - The hypothetical commands 'show w' and 'show c' should show the -appropriate parts of the General Public License. Of course, your -program's commands might be different; for a GUI interface, you would -use an "about box". - - You should also get your employer (if you work as a programmer) or -school, if any, to sign a "copyright disclaimer" for the program, if -necessary. For more information on this, and how to apply and follow -the GNU GPL, see <http://www.gnu.org/licenses/>. - - The GNU General Public License does not permit incorporating your -program into proprietary programs. If your program is a subroutine -library, you may consider it more useful to permit linking proprietary -applications with the library. If this is what you want to do, use the -GNU Lesser General Public License instead of this License. But first, -please read <http://www.gnu.org/philosophy/why-not-lgpl.html>. - - -File: gfortran.info, Node: GNU Free Documentation License, Next: Funding, Prev: Copying, Up: Top - -GNU Free Documentation License -****************************** - - Version 1.3, 3 November 2008 - - Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. - <http://fsf.org/> - - Everyone is permitted to copy and distribute verbatim copies - of this license document, but changing it is not allowed. - - 0. PREAMBLE - - The purpose of this License is to make a manual, textbook, or other - functional and useful document "free" in the sense of freedom: to - assure everyone the effective freedom to copy and redistribute it, - with or without modifying it, either commercially or - noncommercially. Secondarily, this License preserves for the - author and publisher a way to get credit for their work, while not - being considered responsible for modifications made by others. - - This License is a kind of "copyleft", which means that derivative - works of the document must themselves be free in the same sense. - It complements the GNU General Public License, which is a copyleft - license designed for free software. - - We have designed this License in order to use it for manuals for - free software, because free software needs free documentation: a - free program should come with manuals providing the same freedoms - that the software does. 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A copy that is not - "Transparent" is called "Opaque". - - Examples of suitable formats for Transparent copies include plain - ASCII without markup, Texinfo input format, LaTeX input format, - SGML or XML using a publicly available DTD, and standard-conforming - simple HTML, PostScript or PDF designed for human modification. - Examples of transparent image formats include PNG, XCF and JPG. - Opaque formats include proprietary formats that can be read and - edited only by proprietary word processors, SGML or XML for which - the DTD and/or processing tools are not generally available, and - the machine-generated HTML, PostScript or PDF produced by some word - processors for output purposes only. - - The "Title Page" means, for a printed book, the title page itself, - plus such following pages as are needed to hold, legibly, the - material this License requires to appear in the title page. For - works in formats which do not have any title page as such, "Title - Page" means the text near the most prominent appearance of the - work's title, preceding the beginning of the body of the text. - - The "publisher" means any person or entity that distributes copies - of the Document to the public. - - A section "Entitled XYZ" means a named subunit of the Document - whose title either is precisely XYZ or contains XYZ in parentheses - following text that translates XYZ in another language. (Here XYZ - stands for a specific section name mentioned below, such as - "Acknowledgements", "Dedications", "Endorsements", or "History".) - To "Preserve the Title" of such a section when you modify the - Document means that it remains a section "Entitled XYZ" according - to this definition. - - The Document may include Warranty Disclaimers next to the notice - which states that this License applies to the Document. These - Warranty Disclaimers are considered to be included by reference in - this License, but only as regards disclaiming warranties: any other - implication that these Warranty Disclaimers may have is void and - has no effect on the meaning of this License. - - 2. VERBATIM COPYING - - You may copy and distribute the Document in any medium, either - commercially or noncommercially, provided that this License, the - copyright notices, and the license notice saying this License - applies to the Document are reproduced in all copies, and that you - add no other conditions whatsoever to those of this License. You - may not use technical measures to obstruct or control the reading - or further copying of the copies you make or distribute. However, - you may accept compensation in exchange for copies. If you - distribute a large enough number of copies you must also follow the - conditions in section 3. - - You may also lend copies, under the same conditions stated above, - and you may publicly display copies. - - 3. COPYING IN QUANTITY - - If you publish printed copies (or copies in media that commonly - have printed covers) of the Document, numbering more than 100, and - the Document's license notice requires Cover Texts, you must - enclose the copies in covers that carry, clearly and legibly, all - these Cover Texts: Front-Cover Texts on the front cover, and - Back-Cover Texts on the back cover. Both covers must also clearly - and legibly identify you as the publisher of these copies. The - front cover must present the full title with all words of the title - equally prominent and visible. You may add other material on the - covers in addition. Copying with changes limited to the covers, as - long as they preserve the title of the Document and satisfy these - conditions, can be treated as verbatim copying in other respects. - - If the required texts for either cover are too voluminous to fit - legibly, you should put the first ones listed (as many as fit - reasonably) on the actual cover, and continue the rest onto - adjacent pages. - - If you publish or distribute Opaque copies of the Document - numbering more than 100, you must either include a machine-readable - Transparent copy along with each Opaque copy, or state in or with - each Opaque copy a computer-network location from which the general - network-using public has access to download using public-standard - network protocols a complete Transparent copy of the Document, free - of added material. If you use the latter option, you must take - reasonably prudent steps, when you begin distribution of Opaque - copies in quantity, to ensure that this Transparent copy will - remain thus accessible at the stated location until at least one - year after the last time you distribute an Opaque copy (directly or - through your agents or retailers) of that edition to the public. - - It is requested, but not required, that you contact the authors of - the Document well before redistributing any large number of copies, - to give them a chance to provide you with an updated version of the - Document. - - 4. MODIFICATIONS - - You may copy and distribute a Modified Version of the Document - under the conditions of sections 2 and 3 above, provided that you - release the Modified Version under precisely this License, with the - Modified Version filling the role of the Document, thus licensing - distribution and modification of the Modified Version to whoever - possesses a copy of it. In addition, you must do these things in - the Modified Version: - - A. Use in the Title Page (and on the covers, if any) a title - distinct from that of the Document, and from those of previous - versions (which should, if there were any, be listed in the - History section of the Document). You may use the same title - as a previous version if the original publisher of that - version gives permission. - - B. List on the Title Page, as authors, one or more persons or - entities responsible for authorship of the modifications in - the Modified Version, together with at least five of the - principal authors of the Document (all of its principal - authors, if it has fewer than five), unless they release you - from this requirement. - - C. State on the Title page the name of the publisher of the - Modified Version, as the publisher. - - D. Preserve all the copyright notices of the Document. - - E. Add an appropriate copyright notice for your modifications - adjacent to the other copyright notices. - - F. Include, immediately after the copyright notices, a license - notice giving the public permission to use the Modified - Version under the terms of this License, in the form shown in - the Addendum below. - - G. Preserve in that license notice the full lists of Invariant - Sections and required Cover Texts given in the Document's - license notice. - - H. Include an unaltered copy of this License. - - I. Preserve the section Entitled "History", Preserve its Title, - and add to it an item stating at least the title, year, new - authors, and publisher of the Modified Version as given on the - Title Page. If there is no section Entitled "History" in the - Document, create one stating the title, year, authors, and - publisher of the Document as given on its Title Page, then add - an item describing the Modified Version as stated in the - previous sentence. - - J. Preserve the network location, if any, given in the Document - for public access to a Transparent copy of the Document, and - likewise the network locations given in the Document for - previous versions it was based on. These may be placed in the - "History" section. You may omit a network location for a work - that was published at least four years before the Document - itself, or if the original publisher of the version it refers - to gives permission. - - K. For any section Entitled "Acknowledgements" or "Dedications", - Preserve the Title of the section, and preserve in the section - all the substance and tone of each of the contributor - acknowledgements and/or dedications given therein. - - L. Preserve all the Invariant Sections of the Document, unaltered - in their text and in their titles. Section numbers or the - equivalent are not considered part of the section titles. - - M. Delete any section Entitled "Endorsements". Such a section - may not be included in the Modified Version. - - N. Do not retitle any existing section to be Entitled - "Endorsements" or to conflict in title with any Invariant - Section. - - O. Preserve any Warranty Disclaimers. - - If the Modified Version includes new front-matter sections or - appendices that qualify as Secondary Sections and contain no - material copied from the Document, you may at your option designate - some or all of these sections as invariant. To do this, add their - titles to the list of Invariant Sections in the Modified Version's - license notice. These titles must be distinct from any other - section titles. - - You may add a section Entitled "Endorsements", provided it contains - nothing but endorsements of your Modified Version by various - parties--for example, statements of peer review or that the text - has been approved by an organization as the authoritative - definition of a standard. - - You may add a passage of up to five words as a Front-Cover Text, - and a passage of up to 25 words as a Back-Cover Text, to the end of - the list of Cover Texts in the Modified Version. Only one passage - of Front-Cover Text and one of Back-Cover Text may be added by (or - through arrangements made by) any one entity. If the Document - already includes a cover text for the same cover, previously added - by you or by arrangement made by the same entity you are acting on - behalf of, you may not add another; but you may replace the old - one, on explicit permission from the previous publisher that added - the old one. - - The author(s) and publisher(s) of the Document do not by this - License give permission to use their names for publicity for or to - assert or imply endorsement of any Modified Version. - - 5. COMBINING DOCUMENTS - - You may combine the Document with other documents released under - this License, under the terms defined in section 4 above for - modified versions, provided that you include in the combination all - of the Invariant Sections of all of the original documents, - unmodified, and list them all as Invariant Sections of your - combined work in its license notice, and that you preserve all - their Warranty Disclaimers. - - The combined work need only contain one copy of this License, and - multiple identical Invariant Sections may be replaced with a single - copy. If there are multiple Invariant Sections with the same name - but different contents, make the title of each such section unique - by adding at the end of it, in parentheses, the name of the - original author or publisher of that section if known, or else a - unique number. Make the same adjustment to the section titles in - the list of Invariant Sections in the license notice of the - combined work. - - In the combination, you must combine any sections Entitled - "History" in the various original documents, forming one section - Entitled "History"; likewise combine any sections Entitled - "Acknowledgements", and any sections Entitled "Dedications". You - must delete all sections Entitled "Endorsements." - - 6. COLLECTIONS OF DOCUMENTS - - You may make a collection consisting of the Document and other - documents released under this License, and replace the individual - copies of this License in the various documents with a single copy - that is included in the collection, provided that you follow the - rules of this License for verbatim copying of each of the documents - in all other respects. - - You may extract a single document from such a collection, and - distribute it individually under this License, provided you insert - a copy of this License into the extracted document, and follow this - License in all other respects regarding verbatim copying of that - document. - - 7. AGGREGATION WITH INDEPENDENT WORKS - - A compilation of the Document or its derivatives with other - separate and independent documents or works, in or on a volume of a - storage or distribution medium, is called an "aggregate" if the - copyright resulting from the compilation is not used to limit the - legal rights of the compilation's users beyond what the individual - works permit. When the Document is included in an aggregate, this - License does not apply to the other works in the aggregate which - are not themselves derivative works of the Document. - - If the Cover Text requirement of section 3 is applicable to these - copies of the Document, then if the Document is less than one half - of the entire aggregate, the Document's Cover Texts may be placed - on covers that bracket the Document within the aggregate, or the - electronic equivalent of covers if the Document is in electronic - form. Otherwise they must appear on printed covers that bracket - the whole aggregate. - - 8. TRANSLATION - - Translation is considered a kind of modification, so you may - distribute translations of the Document under the terms of section - 4. Replacing Invariant Sections with translations requires special - permission from their copyright holders, but you may include - translations of some or all Invariant Sections in addition to the - original versions of these Invariant Sections. You may include a - translation of this License, and all the license notices in the - Document, and any Warranty Disclaimers, provided that you also - include the original English version of this License and the - original versions of those notices and disclaimers. In case of a - disagreement between the translation and the original version of - this License or a notice or disclaimer, the original version will - prevail. - - If a section in the Document is Entitled "Acknowledgements", - "Dedications", or "History", the requirement (section 4) to - Preserve its Title (section 1) will typically require changing the - actual title. - - 9. TERMINATION - - You may not copy, modify, sublicense, or distribute the Document - except as expressly provided under this License. Any attempt - otherwise to copy, modify, sublicense, or distribute it is void, - and will automatically terminate your rights under this License. - - However, if you cease all violation of this License, then your - license from a particular copyright holder is reinstated (a) - provisionally, unless and until the copyright holder explicitly and - finally terminates your license, and (b) permanently, if the - copyright holder fails to notify you of the violation by some - reasonable means prior to 60 days after the cessation. - - Moreover, your license from a particular copyright holder is - reinstated permanently if the copyright holder notifies you of the - violation by some reasonable means, this is the first time you have - received notice of violation of this License (for any work) from - that copyright holder, and you cure the violation prior to 30 days - after your receipt of the notice. - - Termination of your rights under this section does not terminate - the licenses of parties who have received copies or rights from you - under this License. If your rights have been terminated and not - permanently reinstated, receipt of a copy of some or all of the - same material does not give you any rights to use it. - - 10. FUTURE REVISIONS OF THIS LICENSE - - The Free Software Foundation may publish new, revised versions of - the GNU Free Documentation License from time to time. Such new - versions will be similar in spirit to the present version, but may - differ in detail to address new problems or concerns. See - <http://www.gnu.org/copyleft/>. - - Each version of the License is given a distinguishing version - number. If the Document specifies that a particular numbered - version of this License "or any later version" applies to it, you - have the option of following the terms and conditions either of - that specified version or of any later version that has been - published (not as a draft) by the Free Software Foundation. If the - Document does not specify a version number of this License, you may - choose any version ever published (not as a draft) by the Free - Software Foundation. If the Document specifies that a proxy can - decide which future versions of this License can be used, that - proxy's public statement of acceptance of a version permanently - authorizes you to choose that version for the Document. - - 11. RELICENSING - - "Massive Multiauthor Collaboration Site" (or "MMC Site") means any - World Wide Web server that publishes copyrightable works and also - provides prominent facilities for anybody to edit those works. A - public wiki that anybody can edit is an example of such a server. - A "Massive Multiauthor Collaboration" (or "MMC") contained in the - site means any set of copyrightable works thus published on the MMC - site. - - "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 - license published by Creative Commons Corporation, a not-for-profit - corporation with a principal place of business in San Francisco, - California, as well as future copyleft versions of that license - published by that same organization. - - "Incorporate" means to publish or republish a Document, in whole or - in part, as part of another Document. - - An MMC is "eligible for relicensing" if it is licensed under this - License, and if all works that were first published under this - License somewhere other than this MMC, and subsequently - incorporated in whole or in part into the MMC, (1) had no cover - texts or invariant sections, and (2) were thus incorporated prior - to November 1, 2008. - - The operator of an MMC Site may republish an MMC contained in the - site under CC-BY-SA on the same site at any time before August 1, - 2009, provided the MMC is eligible for relicensing. - -ADDENDUM: How to use this License for your documents -==================================================== - -To use this License in a document you have written, include a copy of -the License in the document and put the following copyright and license -notices just after the title page: - - Copyright (C) YEAR YOUR NAME. - Permission is granted to copy, distribute and/or modify this document - under the terms of the GNU Free Documentation License, Version 1.3 - or any later version published by the Free Software Foundation; - with no Invariant Sections, no Front-Cover Texts, and no Back-Cover - Texts. A copy of the license is included in the section entitled ``GNU - Free Documentation License''. - - If you have Invariant Sections, Front-Cover Texts and Back-Cover -Texts, replace the "with...Texts." line with this: - - with the Invariant Sections being LIST THEIR TITLES, with - the Front-Cover Texts being LIST, and with the Back-Cover Texts - being LIST. - - If you have Invariant Sections without Cover Texts, or some other -combination of the three, merge those two alternatives to suit the -situation. - - If your document contains nontrivial examples of program code, we -recommend releasing these examples in parallel under your choice of free -software license, such as the GNU General Public License, to permit -their use in free software. - - -File: gfortran.info, Node: Funding, Next: Option Index, Prev: GNU Free Documentation License, Up: Top - -Funding Free Software -********************* - -If you want to have more free software a few years from now, it makes -sense for you to help encourage people to contribute funds for its -development. The most effective approach known is to encourage -commercial redistributors to donate. - - Users of free software systems can boost the pace of development by -encouraging for-a-fee distributors to donate part of their selling price -to free software developers--the Free Software Foundation, and others. - - The way to convince distributors to do this is to demand it and -expect it from them. So when you compare distributors, judge them -partly by how much they give to free software development. Show -distributors they must compete to be the one who gives the most. - - To make this approach work, you must insist on numbers that you can -compare, such as, "We will donate ten dollars to the Frobnitz project -for each disk sold." Don't be satisfied with a vague promise, such as -"A portion of the profits are donated," since it doesn't give a basis -for comparison. - - Even a precise fraction "of the profits from this disk" is not very -meaningful, since creative accounting and unrelated business decisions -can greatly alter what fraction of the sales price counts as profit. If -the price you pay is $50, ten percent of the profit is probably less -than a dollar; it might be a few cents, or nothing at all. - - Some redistributors do development work themselves. This is useful -too; but to keep everyone honest, you need to inquire how much they do, -and what kind. Some kinds of development make much more long-term -difference than others. For example, maintaining a separate version of -a program contributes very little; maintaining the standard version of a -program for the whole community contributes much. Easy new ports -contribute little, since someone else would surely do them; difficult -ports such as adding a new CPU to the GNU Compiler Collection contribute -more; major new features or packages contribute the most. - - By establishing the idea that supporting further development is "the -proper thing to do" when distributing free software for a fee, we can -assure a steady flow of resources into making more free software. - - Copyright (C) 1994 Free Software Foundation, Inc. - Verbatim copying and redistribution of this section is permitted - without royalty; alteration is not permitted. - - -File: gfortran.info, Node: Option Index, Next: Keyword Index, Prev: Funding, Up: Top - -Option Index -************ - -'gfortran''s command line options are indexed here without any initial -'-' or '--'. Where an option has both positive and negative forms (such -as -foption and -fno-option), relevant entries in the manual are indexed -under the most appropriate form; it may sometimes be useful to look up -both forms. - - -* Menu: - -* 'A-PREDICATE=ANSWER': Preprocessing Options. - (line 119) -* 'APREDICATE=ANSWER': Preprocessing Options. - (line 113) -* 'backslash': Fortran Dialect Options. - (line 40) -* 'C': Preprocessing Options. - (line 122) -* 'CC': Preprocessing Options. - (line 137) -* 'cpp': Preprocessing Options. - (line 12) -* 'dD': Preprocessing Options. - (line 35) -* 'dI': Preprocessing Options. - (line 51) -* 'dM': Preprocessing Options. - (line 26) -* 'dN': Preprocessing Options. - (line 41) -* 'DNAME': Preprocessing Options. - (line 151) -* 'DNAME=DEFINITION': Preprocessing Options. - (line 154) -* 'dU': Preprocessing Options. - (line 44) -* 'faggressive-function-elimination': Code Gen Options. (line 340) -* 'falign-commons': Code Gen Options. (line 313) -* 'fall-intrinsics': Fortran Dialect Options. - (line 17) -* 'fblas-matmul-limit': Code Gen Options. (line 268) -* 'fbounds-check': Code Gen Options. (line 192) -* 'fcheck': Code Gen Options. (line 142) -* 'fcheck-array-temporaries': Code Gen Options. (line 195) -* 'fcoarray': Code Gen Options. (line 128) -* 'fconvert='CONVERSION: Runtime Options. (line 10) -* 'fcray-pointer': Fortran Dialect Options. - (line 86) -* 'fd-lines-as-code': Fortran Dialect Options. - (line 27) -* 'fd-lines-as-comments': Fortran Dialect Options. - (line 27) -* 'fdefault-double-8': Fortran Dialect Options. - (line 124) -* 'fdefault-integer-8': Fortran Dialect Options. - (line 110) -* 'fdefault-real-8': Fortran Dialect Options. - (line 116) -* 'fdollar-ok': Fortran Dialect Options. - (line 34) -* 'fdump-fortran-optimized': Debugging Options. (line 15) -* 'fdump-fortran-original': Debugging Options. (line 10) -* 'fdump-parse-tree': Debugging Options. (line 19) -* 'fexternal-blas': Code Gen Options. (line 260) -* ff2c: Code Gen Options. (line 25) -* 'ffixed-line-length-'N: Fortran Dialect Options. - (line 57) -* 'ffpe-summary='LIST: Debugging Options. (line 51) -* 'ffpe-trap='LIST: Debugging Options. (line 25) -* 'ffree-form': Fortran Dialect Options. - (line 11) -* 'ffree-line-length-'N: Fortran Dialect Options. - (line 70) -* 'fimplicit-none': Fortran Dialect Options. - (line 81) -* 'finit-character': Code Gen Options. (line 288) -* 'finit-integer': Code Gen Options. (line 288) -* 'finit-local-zero': Code Gen Options. (line 288) -* 'finit-logical': Code Gen Options. (line 288) -* 'finit-real': Code Gen Options. (line 288) -* 'finteger-4-integer-8': Fortran Dialect Options. - (line 133) -* 'fintrinsic-modules-path' DIR: Directory Options. (line 36) -* 'fmax-array-constructor': Code Gen Options. (line 198) -* 'fmax-errors='N: Error and Warning Options. - (line 27) -* 'fmax-identifier-length='N: Fortran Dialect Options. - (line 77) -* 'fmax-stack-var-size': Code Gen Options. (line 216) -* 'fmax-subrecord-length='LENGTH: Runtime Options. (line 29) -* 'fmodule-private': Fortran Dialect Options. - (line 52) -* 'fno-automatic': Code Gen Options. (line 15) -* 'fno-backtrace': Debugging Options. (line 61) -* 'fno-fixed-form': Fortran Dialect Options. - (line 11) -* 'fno-protect-parens': Code Gen Options. (line 325) -* 'fno-underscoring': Code Gen Options. (line 54) -* 'fopenmp': Fortran Dialect Options. - (line 90) -* 'fpack-derived': Code Gen Options. (line 238) -* 'fpp': Preprocessing Options. - (line 12) -* 'frange-check': Fortran Dialect Options. - (line 98) -* 'freal-4-real-10': Fortran Dialect Options. - (line 148) -* 'freal-4-real-16': Fortran Dialect Options. - (line 148) -* 'freal-4-real-8': Fortran Dialect Options. - (line 148) -* 'freal-8-real-10': Fortran Dialect Options. - (line 148) -* 'freal-8-real-16': Fortran Dialect Options. - (line 148) -* 'freal-8-real-4': Fortran Dialect Options. - (line 148) -* 'frealloc-lhs': Code Gen Options. (line 334) -* 'frecord-marker='LENGTH: Runtime Options. (line 21) -* 'frecursive': Code Gen Options. (line 279) -* 'frepack-arrays': Code Gen Options. (line 244) -* 'frontend-optimize': Code Gen Options. (line 348) -* 'fsecond-underscore': Code Gen Options. (line 111) -* 'fshort-enums': Code Gen Options. (line 254) -* 'fshort-enums' <1>: Fortran 2003 status. (line 93) -* 'fsign-zero': Runtime Options. (line 34) -* 'fstack-arrays': Code Gen Options. (line 230) -* 'fsyntax-only': Error and Warning Options. - (line 33) -* 'fworking-directory': Preprocessing Options. - (line 55) -* 'H': Preprocessing Options. - (line 174) -* 'I'DIR: Directory Options. (line 14) -* 'idirafter DIR': Preprocessing Options. - (line 69) -* 'imultilib DIR': Preprocessing Options. - (line 76) -* 'iprefix PREFIX': Preprocessing Options. - (line 80) -* 'iquote DIR': Preprocessing Options. - (line 89) -* 'isysroot DIR': Preprocessing Options. - (line 85) -* 'isystem DIR': Preprocessing Options. - (line 96) -* 'J'DIR: Directory Options. (line 29) -* 'M'DIR: Directory Options. (line 29) -* 'nostdinc': Preprocessing Options. - (line 104) -* 'P': Preprocessing Options. - (line 179) -* 'pedantic': Error and Warning Options. - (line 38) -* 'pedantic-errors': Error and Warning Options. - (line 57) -* 'static-libgfortran': Link Options. (line 11) -* 'std='STD option: Fortran Dialect Options. - (line 159) -* 'UNAME': Preprocessing Options. - (line 185) -* 'undef': Preprocessing Options. - (line 109) -* 'Waliasing': Error and Warning Options. - (line 69) -* 'Walign-commons': Error and Warning Options. - (line 198) -* 'Wall': Error and Warning Options. - (line 61) -* 'Wampersand': Error and Warning Options. - (line 86) -* 'Warray-temporaries': Error and Warning Options. - (line 94) -* 'Wc-binding-type': Error and Warning Options. - (line 99) -* 'Wcharacter-truncation': Error and Warning Options. - (line 106) -* 'Wcompare-reals': Error and Warning Options. - (line 225) -* 'Wconversion': Error and Warning Options. - (line 113) -* 'Wconversion-extra': Error and Warning Options. - (line 117) -* 'Werror': Error and Warning Options. - (line 237) -* 'Wextra': Error and Warning Options. - (line 120) -* 'Wfunction-elimination': Error and Warning Options. - (line 204) -* 'Wimplicit-interface': Error and Warning Options. - (line 125) -* 'Wimplicit-procedure': Error and Warning Options. - (line 131) -* 'Wintrinsic-shadow': Error and Warning Options. - (line 180) -* 'Wintrinsics-std': Error and Warning Options. - (line 135) -* 'Wline-truncation': Error and Warning Options. - (line 109) -* 'Wreal-q-constant': Error and Warning Options. - (line 142) -* 'Wrealloc-lhs': Error and Warning Options. - (line 208) -* 'Wrealloc-lhs-all': Error and Warning Options. - (line 220) -* 'Wsurprising': Error and Warning Options. - (line 146) -* 'Wtabs': Error and Warning Options. - (line 168) -* 'Wtargt-lifetime': Error and Warning Options. - (line 229) -* 'Wunderflow': Error and Warning Options. - (line 176) -* 'Wunused-dummy-argument': Error and Warning Options. - (line 187) -* 'Wunused-parameter': Error and Warning Options. - (line 191) -* 'Wzerotrip': Error and Warning Options. - (line 233) - - -File: gfortran.info, Node: Keyword Index, Prev: Option Index, Up: Top - -Keyword Index -************* - - -* Menu: - -* '$': Fortran Dialect Options. - (line 34) -* '%LOC': Argument list functions. - (line 6) -* '%REF': Argument list functions. - (line 6) -* '%VAL': Argument list functions. - (line 6) -* '&': Error and Warning Options. - (line 86) -* '[...]': Fortran 2003 status. (line 78) -* _gfortran_set_args: _gfortran_set_args. (line 6) -* _gfortran_set_convert: _gfortran_set_convert. - (line 6) -* _gfortran_set_fpe: _gfortran_set_fpe. (line 6) -* _gfortran_set_max_subrecord_length: _gfortran_set_max_subrecord_length. - (line 6) -* _gfortran_set_options: _gfortran_set_options. - (line 6) -* _gfortran_set_record_marker: _gfortran_set_record_marker. - (line 6) -* ABORT: ABORT. (line 6) -* ABS: ABS. (line 6) -* absolute value: ABS. (line 6) -* ACCESS: ACCESS. (line 6) -* 'ACCESS='STREAM'' I/O: Fortran 2003 status. (line 103) -* ACHAR: ACHAR. (line 6) -* ACOS: ACOS. (line 6) -* ACOSH: ACOSH. (line 6) -* adjust string: ADJUSTL. (line 6) -* adjust string <1>: ADJUSTR. (line 6) -* ADJUSTL: ADJUSTL. (line 6) -* ADJUSTR: ADJUSTR. (line 6) -* AIMAG: AIMAG. (line 6) -* AINT: AINT. (line 6) -* ALARM: ALARM. (line 6) -* ALGAMA: LOG_GAMMA. (line 6) -* aliasing: Error and Warning Options. - (line 69) -* alignment of 'COMMON' blocks: Error and Warning Options. - (line 198) -* alignment of 'COMMON' blocks <1>: Code Gen Options. (line 313) -* ALL: ALL. (line 6) -* all warnings: Error and Warning Options. - (line 61) -* 'ALLOCATABLE' components of derived types: Fortran 2003 status. - (line 101) -* 'ALLOCATABLE' dummy arguments: Fortran 2003 status. (line 99) -* 'ALLOCATABLE' function results: Fortran 2003 status. (line 100) -* ALLOCATED: ALLOCATED. (line 6) -* allocation, moving: MOVE_ALLOC. (line 6) -* allocation, status: ALLOCATED. (line 6) -* ALOG: LOG. (line 6) -* ALOG10: LOG10. (line 6) -* AMAX0: MAX. (line 6) -* AMAX1: MAX. (line 6) -* AMIN0: MIN. (line 6) -* AMIN1: MIN. (line 6) -* AMOD: MOD. (line 6) -* AND: AND. (line 6) -* ANINT: ANINT. (line 6) -* ANY: ANY. (line 6) -* area hyperbolic cosine: ACOSH. (line 6) -* area hyperbolic sine: ASINH. (line 6) -* area hyperbolic tangent: ATANH. (line 6) -* argument list functions: Argument list functions. - (line 6) -* arguments, to program: COMMAND_ARGUMENT_COUNT. - (line 6) -* arguments, to program <1>: GETARG. (line 6) -* arguments, to program <2>: GET_COMMAND. (line 6) -* arguments, to program <3>: GET_COMMAND_ARGUMENT. - (line 6) -* arguments, to program <4>: IARGC. (line 6) -* array, add elements: SUM. (line 6) -* array, AND: IALL. (line 6) -* array, apply condition: ALL. (line 6) -* array, apply condition <1>: ANY. (line 6) -* array, bounds checking: Code Gen Options. (line 142) -* array, change dimensions: RESHAPE. (line 6) -* array, combine arrays: MERGE. (line 6) -* array, condition testing: ALL. (line 6) -* array, condition testing <1>: ANY. (line 6) -* array, conditionally add elements: SUM. (line 6) -* array, conditionally count elements: COUNT. (line 6) -* array, conditionally multiply elements: PRODUCT. (line 6) -* array, constructors: Fortran 2003 status. (line 78) -* array, count elements: SIZE. (line 6) -* array, duplicate dimensions: SPREAD. (line 6) -* array, duplicate elements: SPREAD. (line 6) -* array, element counting: COUNT. (line 6) -* array, gather elements: PACK. (line 6) -* array, increase dimension: SPREAD. (line 6) -* array, increase dimension <1>: UNPACK. (line 6) -* array, indices of type real: Real array indices. (line 6) -* array, location of maximum element: MAXLOC. (line 6) -* array, location of minimum element: MINLOC. (line 6) -* array, lower bound: LBOUND. (line 6) -* array, maximum value: MAXVAL. (line 6) -* array, merge arrays: MERGE. (line 6) -* array, minimum value: MINVAL. (line 6) -* array, multiply elements: PRODUCT. (line 6) -* array, number of elements: COUNT. (line 6) -* array, number of elements <1>: SIZE. (line 6) -* array, OR: IANY. (line 6) -* array, packing: PACK. (line 6) -* array, parity: IPARITY. (line 6) -* array, permutation: CSHIFT. (line 6) -* array, product: PRODUCT. (line 6) -* array, reduce dimension: PACK. (line 6) -* array, rotate: CSHIFT. (line 6) -* array, scatter elements: UNPACK. (line 6) -* array, shape: SHAPE. (line 6) -* array, shift: EOSHIFT. (line 6) -* array, shift circularly: CSHIFT. (line 6) -* array, size: SIZE. (line 6) -* array, sum: SUM. (line 6) -* array, transmogrify: RESHAPE. (line 6) -* array, transpose: TRANSPOSE. (line 6) -* array, unpacking: UNPACK. (line 6) -* array, upper bound: UBOUND. (line 6) -* array, XOR: IPARITY. (line 6) -* ASCII collating sequence: ACHAR. (line 6) -* ASCII collating sequence <1>: IACHAR. (line 6) -* ASIN: ASIN. (line 6) -* ASINH: ASINH. (line 6) -* ASSOCIATED: ASSOCIATED. (line 6) -* association status: ASSOCIATED. (line 6) -* association status, C pointer: C_ASSOCIATED. (line 6) -* ATAN: ATAN. (line 6) -* ATAN2: ATAN2. (line 6) -* ATANH: ATANH. (line 6) -* Atomic subroutine, define: ATOMIC_DEFINE. (line 6) -* Atomic subroutine, reference: ATOMIC_REF. (line 6) -* ATOMIC_DEFINE: ATOMIC_DEFINE. (line 6) -* ATOMIC_REF: ATOMIC_REF. (line 6) -* Authors: Contributors. (line 6) -* backslash: Fortran Dialect Options. - (line 40) -* BACKTRACE: BACKTRACE. (line 6) -* backtrace: Debugging Options. (line 61) -* backtrace <1>: BACKTRACE. (line 6) -* base 10 logarithm function: LOG10. (line 6) -* BESJ0: BESSEL_J0. (line 6) -* BESJ1: BESSEL_J1. (line 6) -* BESJN: BESSEL_JN. (line 6) -* Bessel function, first kind: BESSEL_J0. (line 6) -* Bessel function, first kind <1>: BESSEL_J1. (line 6) -* Bessel function, first kind <2>: BESSEL_JN. (line 6) -* Bessel function, second kind: BESSEL_Y0. (line 6) -* Bessel function, second kind <1>: BESSEL_Y1. (line 6) -* Bessel function, second kind <2>: BESSEL_YN. (line 6) -* BESSEL_J0: BESSEL_J0. (line 6) -* BESSEL_J1: BESSEL_J1. (line 6) -* BESSEL_JN: BESSEL_JN. (line 6) -* BESSEL_Y0: BESSEL_Y0. (line 6) -* BESSEL_Y1: BESSEL_Y1. (line 6) -* BESSEL_YN: BESSEL_YN. (line 6) -* BESY0: BESSEL_Y0. (line 6) -* BESY1: BESSEL_Y1. (line 6) -* BESYN: BESSEL_YN. (line 6) -* BGE: BGE. (line 6) -* BGT: BGT. (line 6) -* binary representation: POPCNT. (line 6) -* binary representation <1>: POPPAR. (line 6) -* bits set: POPCNT. (line 6) -* bits, AND of array elements: IALL. (line 6) -* bits, clear: IBCLR. (line 6) -* bits, extract: IBITS. (line 6) -* bits, get: IBITS. (line 6) -* bits, merge: MERGE_BITS. (line 6) -* bits, move: MVBITS. (line 6) -* bits, move <1>: TRANSFER. (line 6) -* bits, negate: NOT. (line 6) -* bits, number of: BIT_SIZE. (line 6) -* bits, OR of array elements: IANY. (line 6) -* bits, set: IBSET. (line 6) -* bits, shift: ISHFT. (line 6) -* bits, shift circular: ISHFTC. (line 6) -* bits, shift left: LSHIFT. (line 6) -* bits, shift left <1>: SHIFTL. (line 6) -* bits, shift right: RSHIFT. (line 6) -* bits, shift right <1>: SHIFTA. (line 6) -* bits, shift right <2>: SHIFTR. (line 6) -* bits, testing: BTEST. (line 6) -* bits, unset: IBCLR. (line 6) -* bits, XOR of array elements: IPARITY. (line 6) -* bitwise comparison: BGE. (line 6) -* bitwise comparison <1>: BGT. (line 6) -* bitwise comparison <2>: BLE. (line 6) -* bitwise comparison <3>: BLT. (line 6) -* bitwise logical and: AND. (line 6) -* bitwise logical and <1>: IAND. (line 6) -* bitwise logical exclusive or: IEOR. (line 6) -* bitwise logical exclusive or <1>: XOR. (line 6) -* bitwise logical not: NOT. (line 6) -* bitwise logical or: IOR. (line 6) -* bitwise logical or <1>: OR. (line 6) -* BIT_SIZE: BIT_SIZE. (line 6) -* BLE: BLE. (line 6) -* BLT: BLT. (line 6) -* bounds checking: Code Gen Options. (line 142) -* BOZ literal constants: BOZ literal constants. - (line 6) -* BTEST: BTEST. (line 6) -* CABS: ABS. (line 6) -* calling convention: Code Gen Options. (line 25) -* CCOS: COS. (line 6) -* CDABS: ABS. (line 6) -* CDCOS: COS. (line 6) -* CDEXP: EXP. (line 6) -* CDLOG: LOG. (line 6) -* CDSIN: SIN. (line 6) -* CDSQRT: SQRT. (line 6) -* CEILING: CEILING. (line 6) -* ceiling: ANINT. (line 6) -* ceiling <1>: CEILING. (line 6) -* CEXP: EXP. (line 6) -* CHAR: CHAR. (line 6) -* character kind: SELECTED_CHAR_KIND. (line 6) -* character set: Fortran Dialect Options. - (line 34) -* CHDIR: CHDIR. (line 6) -* checking array temporaries: Code Gen Options. (line 142) -* checking subscripts: Code Gen Options. (line 142) -* CHMOD: CHMOD. (line 6) -* clock ticks: MCLOCK. (line 6) -* clock ticks <1>: MCLOCK8. (line 6) -* clock ticks <2>: SYSTEM_CLOCK. (line 6) -* CLOG: LOG. (line 6) -* CMPLX: CMPLX. (line 6) -* coarray, 'IMAGE_INDEX': IMAGE_INDEX. (line 6) -* coarray, lower bound: LCOBOUND. (line 6) -* coarray, 'NUM_IMAGES': NUM_IMAGES. (line 6) -* coarray, 'THIS_IMAGE': THIS_IMAGE. (line 6) -* coarray, upper bound: UCOBOUND. (line 6) -* coarrays: Code Gen Options. (line 128) -* code generation, conventions: Code Gen Options. (line 6) -* collating sequence, ASCII: ACHAR. (line 6) -* collating sequence, ASCII <1>: IACHAR. (line 6) -* command line: EXECUTE_COMMAND_LINE. - (line 6) -* command options: Invoking GNU Fortran. - (line 6) -* command-line arguments: COMMAND_ARGUMENT_COUNT. - (line 6) -* command-line arguments <1>: GETARG. (line 6) -* command-line arguments <2>: GET_COMMAND. (line 6) -* command-line arguments <3>: GET_COMMAND_ARGUMENT. - (line 6) -* command-line arguments <4>: IARGC. (line 6) -* command-line arguments, number of: COMMAND_ARGUMENT_COUNT. - (line 6) -* command-line arguments, number of <1>: IARGC. (line 6) -* COMMAND_ARGUMENT_COUNT: COMMAND_ARGUMENT_COUNT. - (line 6) -* 'COMMON': Volatile COMMON blocks. - (line 6) -* compiler flags inquiry function: COMPILER_OPTIONS. (line 6) -* compiler, name and version: COMPILER_VERSION. (line 6) -* COMPILER_OPTIONS: COMPILER_OPTIONS. (line 6) -* COMPILER_VERSION: COMPILER_VERSION. (line 6) -* COMPLEX: COMPLEX. (line 6) -* complex conjugate: CONJG. (line 6) -* Complex function: Alternate complex function syntax. - (line 6) -* complex numbers, conversion to: CMPLX. (line 6) -* complex numbers, conversion to <1>: COMPLEX. (line 6) -* complex numbers, conversion to <2>: DCMPLX. (line 6) -* complex numbers, imaginary part: AIMAG. (line 6) -* complex numbers, real part: DREAL. (line 6) -* complex numbers, real part <1>: REAL. (line 6) -* Conditional compilation: Preprocessing and conditional compilation. - (line 6) -* CONJG: CONJG. (line 6) -* consistency, durability: Data consistency and durability. - (line 6) -* Contributing: Contributing. (line 6) -* Contributors: Contributors. (line 6) -* conversion: Error and Warning Options. - (line 113) -* conversion <1>: Error and Warning Options. - (line 117) -* conversion, to character: CHAR. (line 6) -* conversion, to complex: CMPLX. (line 6) -* conversion, to complex <1>: COMPLEX. (line 6) -* conversion, to complex <2>: DCMPLX. (line 6) -* conversion, to integer: Implicitly convert LOGICAL and INTEGER values. - (line 6) -* conversion, to integer <1>: IACHAR. (line 6) -* conversion, to integer <2>: ICHAR. (line 6) -* conversion, to integer <3>: INT. (line 6) -* conversion, to integer <4>: INT2. (line 6) -* conversion, to integer <5>: INT8. (line 6) -* conversion, to integer <6>: LONG. (line 6) -* conversion, to logical: Implicitly convert LOGICAL and INTEGER values. - (line 6) -* conversion, to logical <1>: LOGICAL. (line 6) -* conversion, to real: DBLE. (line 6) -* conversion, to real <1>: REAL. (line 6) -* conversion, to string: CTIME. (line 6) -* 'CONVERT' specifier: CONVERT specifier. (line 6) -* core, dump: ABORT. (line 6) -* COS: COS. (line 6) -* COSH: COSH. (line 6) -* cosine: COS. (line 6) -* cosine, hyperbolic: COSH. (line 6) -* cosine, hyperbolic, inverse: ACOSH. (line 6) -* cosine, inverse: ACOS. (line 6) -* COUNT: COUNT. (line 6) -* CPP: Preprocessing and conditional compilation. - (line 6) -* CPP <1>: Preprocessing Options. - (line 6) -* CPU_TIME: CPU_TIME. (line 6) -* Credits: Contributors. (line 6) -* CSHIFT: CSHIFT. (line 6) -* CSIN: SIN. (line 6) -* CSQRT: SQRT. (line 6) -* CTIME: CTIME. (line 6) -* current date: DATE_AND_TIME. (line 6) -* current date <1>: FDATE. (line 6) -* current date <2>: IDATE. (line 6) -* current time: DATE_AND_TIME. (line 6) -* current time <1>: FDATE. (line 6) -* current time <2>: ITIME. (line 6) -* current time <3>: TIME. (line 6) -* current time <4>: TIME8. (line 6) -* C_ASSOCIATED: C_ASSOCIATED. (line 6) -* C_FUNLOC: C_FUNLOC. (line 6) -* C_F_POINTER: C_F_POINTER. (line 6) -* C_F_PROCPOINTER: C_F_PROCPOINTER. (line 6) -* C_LOC: C_LOC. (line 6) -* C_SIZEOF: C_SIZEOF. (line 6) -* DABS: ABS. (line 6) -* DACOS: ACOS. (line 6) -* DACOSH: ACOSH. (line 6) -* DASIN: ASIN. (line 6) -* DASINH: ASINH. (line 6) -* DATAN: ATAN. (line 6) -* DATAN2: ATAN2. (line 6) -* DATANH: ATANH. (line 6) -* date, current: DATE_AND_TIME. (line 6) -* date, current <1>: FDATE. (line 6) -* date, current <2>: IDATE. (line 6) -* DATE_AND_TIME: DATE_AND_TIME. (line 6) -* DBESJ0: BESSEL_J0. (line 6) -* DBESJ1: BESSEL_J1. (line 6) -* DBESJN: BESSEL_JN. (line 6) -* DBESY0: BESSEL_Y0. (line 6) -* DBESY1: BESSEL_Y1. (line 6) -* DBESYN: BESSEL_YN. (line 6) -* DBLE: DBLE. (line 6) -* DCMPLX: DCMPLX. (line 6) -* DCONJG: CONJG. (line 6) -* DCOS: COS. (line 6) -* DCOSH: COSH. (line 6) -* DDIM: DIM. (line 6) -* debugging information options: Debugging Options. (line 6) -* debugging, preprocessor: Preprocessing Options. - (line 26) -* debugging, preprocessor <1>: Preprocessing Options. - (line 35) -* debugging, preprocessor <2>: Preprocessing Options. - (line 41) -* debugging, preprocessor <3>: Preprocessing Options. - (line 44) -* debugging, preprocessor <4>: Preprocessing Options. - (line 51) -* 'DECODE': ENCODE and DECODE statements. - (line 6) -* delayed execution: ALARM. (line 6) -* delayed execution <1>: SLEEP. (line 6) -* DEXP: EXP. (line 6) -* DFLOAT: REAL. (line 6) -* DGAMMA: GAMMA. (line 6) -* dialect options: Fortran Dialect Options. - (line 6) -* DIGITS: DIGITS. (line 6) -* DIM: DIM. (line 6) -* DIMAG: AIMAG. (line 6) -* DINT: AINT. (line 6) -* directive, 'INCLUDE': Directory Options. (line 6) -* directory, options: Directory Options. (line 6) -* directory, search paths for inclusion: Directory Options. (line 14) -* division, modulo: MODULO. (line 6) -* division, remainder: MOD. (line 6) -* DLGAMA: LOG_GAMMA. (line 6) -* DLOG: LOG. (line 6) -* DLOG10: LOG10. (line 6) -* DMAX1: MAX. (line 6) -* DMIN1: MIN. (line 6) -* DMOD: MOD. (line 6) -* DNINT: ANINT. (line 6) -* dot product: DOT_PRODUCT. (line 6) -* DOT_PRODUCT: DOT_PRODUCT. (line 6) -* DPROD: DPROD. (line 6) -* DREAL: DREAL. (line 6) -* DSHIFTL: DSHIFTL. (line 6) -* DSHIFTR: DSHIFTR. (line 6) -* DSIGN: SIGN. (line 6) -* DSIN: SIN. (line 6) -* DSINH: SINH. (line 6) -* DSQRT: SQRT. (line 6) -* DTAN: TAN. (line 6) -* DTANH: TANH. (line 6) -* DTIME: DTIME. (line 6) -* dummy argument, unused: Error and Warning Options. - (line 187) -* elapsed time: DTIME. (line 6) -* elapsed time <1>: SECNDS. (line 6) -* elapsed time <2>: SECOND. (line 6) -* Elimination of functions with identical argument lists: Code Gen Options. - (line 340) -* 'ENCODE': ENCODE and DECODE statements. - (line 6) -* 'ENUM' statement: Fortran 2003 status. (line 93) -* 'ENUMERATOR' statement: Fortran 2003 status. (line 93) -* environment variable: Environment Variables. - (line 6) -* environment variable <1>: Runtime. (line 6) -* environment variable <2>: GETENV. (line 6) -* environment variable <3>: GET_ENVIRONMENT_VARIABLE. - (line 6) -* EOSHIFT: EOSHIFT. (line 6) -* EPSILON: EPSILON. (line 6) -* ERF: ERF. (line 6) -* ERFC: ERFC. (line 6) -* ERFC_SCALED: ERFC_SCALED. (line 6) -* error function: ERF. (line 6) -* error function, complementary: ERFC. (line 6) -* error function, complementary, exponentially-scaled: ERFC_SCALED. - (line 6) -* errors, limiting: Error and Warning Options. - (line 27) -* escape characters: Fortran Dialect Options. - (line 40) -* ETIME: ETIME. (line 6) -* Euclidean distance: HYPOT. (line 6) -* Euclidean vector norm: NORM2. (line 6) -* EXECUTE_COMMAND_LINE: EXECUTE_COMMAND_LINE. - (line 6) -* EXIT: EXIT. (line 6) -* EXP: EXP. (line 6) -* EXPONENT: EXPONENT. (line 6) -* exponential function: EXP. (line 6) -* exponential function, inverse: LOG. (line 6) -* exponential function, inverse <1>: LOG10. (line 6) -* expression size: C_SIZEOF. (line 6) -* expression size <1>: SIZEOF. (line 6) -* EXTENDS_TYPE_OF: EXTENDS_TYPE_OF. (line 6) -* extensions: Extensions. (line 6) -* extensions, implemented: Extensions implemented in GNU Fortran. - (line 6) -* extensions, not implemented: Extensions not implemented in GNU Fortran. - (line 6) -* extra warnings: Error and Warning Options. - (line 120) -* 'f2c' calling convention: Code Gen Options. (line 25) -* 'f2c' calling convention <1>: Code Gen Options. (line 111) -* Factorial function: GAMMA. (line 6) -* FDATE: FDATE. (line 6) -* FDL, GNU Free Documentation License: GNU Free Documentation License. - (line 6) -* FGET: FGET. (line 6) -* FGETC: FGETC. (line 6) -* file format, fixed: Fortran Dialect Options. - (line 11) -* file format, fixed <1>: Fortran Dialect Options. - (line 57) -* file format, free: Fortran Dialect Options. - (line 11) -* file format, free <1>: Fortran Dialect Options. - (line 70) -* file operation, file number: FNUM. (line 6) -* file operation, flush: FLUSH. (line 6) -* file operation, position: FSEEK. (line 6) -* file operation, position <1>: FTELL. (line 6) -* file operation, read character: FGET. (line 6) -* file operation, read character <1>: FGETC. (line 6) -* file operation, seek: FSEEK. (line 6) -* file operation, write character: FPUT. (line 6) -* file operation, write character <1>: FPUTC. (line 6) -* file system, access mode: ACCESS. (line 6) -* file system, change access mode: CHMOD. (line 6) -* file system, create link: LINK. (line 6) -* file system, create link <1>: SYMLNK. (line 6) -* file system, file creation mask: UMASK. (line 6) -* file system, file status: FSTAT. (line 6) -* file system, file status <1>: LSTAT. (line 6) -* file system, file status <2>: STAT. (line 6) -* file system, hard link: LINK. (line 6) -* file system, remove file: UNLINK. (line 6) -* file system, rename file: RENAME. (line 6) -* file system, soft link: SYMLNK. (line 6) -* flags inquiry function: COMPILER_OPTIONS. (line 6) -* FLOAT: REAL. (line 6) -* floating point, exponent: EXPONENT. (line 6) -* floating point, fraction: FRACTION. (line 6) -* floating point, nearest different: NEAREST. (line 6) -* floating point, relative spacing: RRSPACING. (line 6) -* floating point, relative spacing <1>: SPACING. (line 6) -* floating point, scale: SCALE. (line 6) -* floating point, set exponent: SET_EXPONENT. (line 6) -* FLOOR: FLOOR. (line 6) -* floor: AINT. (line 6) -* floor <1>: FLOOR. (line 6) -* FLUSH: FLUSH. (line 6) -* 'FLUSH' statement: Fortran 2003 status. (line 89) -* FNUM: FNUM. (line 6) -* 'FORMAT': Variable FORMAT expressions. - (line 6) -* Fortran 77: GNU Fortran and G77. (line 6) -* FPP: Preprocessing and conditional compilation. - (line 6) -* FPUT: FPUT. (line 6) -* FPUTC: FPUTC. (line 6) -* FRACTION: FRACTION. (line 6) -* FREE: FREE. (line 6) -* Front-end optimization: Code Gen Options. (line 348) -* FSEEK: FSEEK. (line 6) -* FSTAT: FSTAT. (line 6) -* FTELL: FTELL. (line 6) -* function elimination: Error and Warning Options. - (line 204) -* 'g77': GNU Fortran and G77. (line 6) -* 'g77' calling convention: Code Gen Options. (line 25) -* 'g77' calling convention <1>: Code Gen Options. (line 111) -* GAMMA: GAMMA. (line 6) -* Gamma function: GAMMA. (line 6) -* Gamma function, logarithm of: LOG_GAMMA. (line 6) -* GCC: GNU Fortran and GCC. (line 6) -* GERROR: GERROR. (line 6) -* GETARG: GETARG. (line 6) -* GETCWD: GETCWD. (line 6) -* GETENV: GETENV. (line 6) -* GETGID: GETGID. (line 6) -* GETLOG: GETLOG. (line 6) -* GETPID: GETPID. (line 6) -* GETUID: GETUID. (line 6) -* GET_COMMAND: GET_COMMAND. (line 6) -* GET_COMMAND_ARGUMENT: GET_COMMAND_ARGUMENT. - (line 6) -* GET_ENVIRONMENT_VARIABLE: GET_ENVIRONMENT_VARIABLE. - (line 6) -* GMTIME: GMTIME. (line 6) -* GNU Compiler Collection: GNU Fortran and GCC. (line 6) -* GNU Fortran command options: Invoking GNU Fortran. - (line 6) -* Hollerith constants: Hollerith constants support. - (line 6) -* HOSTNM: HOSTNM. (line 6) -* HUGE: HUGE. (line 6) -* hyperbolic cosine: COSH. (line 6) -* hyperbolic function, cosine: COSH. (line 6) -* hyperbolic function, cosine, inverse: ACOSH. (line 6) -* hyperbolic function, sine: SINH. (line 6) -* hyperbolic function, sine, inverse: ASINH. (line 6) -* hyperbolic function, tangent: TANH. (line 6) -* hyperbolic function, tangent, inverse: ATANH. (line 6) -* hyperbolic sine: SINH. (line 6) -* hyperbolic tangent: TANH. (line 6) -* HYPOT: HYPOT. (line 6) -* I/O item lists: I/O item lists. (line 6) -* IABS: ABS. (line 6) -* IACHAR: IACHAR. (line 6) -* IALL: IALL. (line 6) -* IAND: IAND. (line 6) -* IANY: IANY. (line 6) -* IARGC: IARGC. (line 6) -* IBCLR: IBCLR. (line 6) -* IBITS: IBITS. (line 6) -* IBSET: IBSET. (line 6) -* ICHAR: ICHAR. (line 6) -* IDATE: IDATE. (line 6) -* IDIM: DIM. (line 6) -* IDINT: INT. (line 6) -* IDNINT: NINT. (line 6) -* IEEE, ISNAN: ISNAN. (line 6) -* IEOR: IEOR. (line 6) -* IERRNO: IERRNO. (line 6) -* IFIX: INT. (line 6) -* IMAG: AIMAG. (line 6) -* images, cosubscript to image index conversion: IMAGE_INDEX. (line 6) -* images, index of this image: THIS_IMAGE. (line 6) -* images, number of: NUM_IMAGES. (line 6) -* IMAGE_INDEX: IMAGE_INDEX. (line 6) -* IMAGPART: AIMAG. (line 6) -* 'IMPORT' statement: Fortran 2003 status. (line 120) -* 'INCLUDE' directive: Directory Options. (line 6) -* inclusion, directory search paths for: Directory Options. (line 14) -* INDEX: INDEX intrinsic. (line 6) -* INT: INT. (line 6) -* INT2: INT2. (line 6) -* INT8: INT8. (line 6) -* integer kind: SELECTED_INT_KIND. (line 6) -* Interoperability: Mixed-Language Programming. - (line 6) -* intrinsic: Error and Warning Options. - (line 180) -* intrinsic Modules: Intrinsic Modules. (line 6) -* intrinsic procedures: Intrinsic Procedures. - (line 6) -* Introduction: Top. (line 6) -* inverse hyperbolic cosine: ACOSH. (line 6) -* inverse hyperbolic sine: ASINH. (line 6) -* inverse hyperbolic tangent: ATANH. (line 6) -* 'IOMSG=' specifier: Fortran 2003 status. (line 91) -* IOR: IOR. (line 6) -* 'IOSTAT', end of file: IS_IOSTAT_END. (line 6) -* 'IOSTAT', end of record: IS_IOSTAT_EOR. (line 6) -* IPARITY: IPARITY. (line 6) -* IRAND: IRAND. (line 6) -* ISATTY: ISATTY. (line 6) -* ISHFT: ISHFT. (line 6) -* ISHFTC: ISHFTC. (line 6) -* ISIGN: SIGN. (line 6) -* ISNAN: ISNAN. (line 6) -* 'ISO_FORTRAN_ENV' statement: Fortran 2003 status. (line 128) -* IS_IOSTAT_END: IS_IOSTAT_END. (line 6) -* IS_IOSTAT_EOR: IS_IOSTAT_EOR. (line 6) -* ITIME: ITIME. (line 6) -* KILL: KILL. (line 6) -* KIND: KIND. (line 6) -* kind: KIND Type Parameters. - (line 6) -* kind <1>: KIND. (line 6) -* kind, character: SELECTED_CHAR_KIND. (line 6) -* kind, integer: SELECTED_INT_KIND. (line 6) -* kind, old-style: Old-style kind specifications. - (line 6) -* kind, real: SELECTED_REAL_KIND. (line 6) -* L2 vector norm: NORM2. (line 6) -* language, dialect options: Fortran Dialect Options. - (line 6) -* LBOUND: LBOUND. (line 6) -* LCOBOUND: LCOBOUND. (line 6) -* LEADZ: LEADZ. (line 6) -* left shift, combined: DSHIFTL. (line 6) -* LEN: LEN. (line 6) -* LEN_TRIM: LEN_TRIM. (line 6) -* lexical comparison of strings: LGE. (line 6) -* lexical comparison of strings <1>: LGT. (line 6) -* lexical comparison of strings <2>: LLE. (line 6) -* lexical comparison of strings <3>: LLT. (line 6) -* LGAMMA: LOG_GAMMA. (line 6) -* LGE: LGE. (line 6) -* LGT: LGT. (line 6) -* libf2c calling convention: Code Gen Options. (line 25) -* libf2c calling convention <1>: Code Gen Options. (line 111) -* libgfortran initialization, set_args: _gfortran_set_args. (line 6) -* libgfortran initialization, set_convert: _gfortran_set_convert. - (line 6) -* libgfortran initialization, set_fpe: _gfortran_set_fpe. (line 6) -* libgfortran initialization, set_max_subrecord_length: _gfortran_set_max_subrecord_length. - (line 6) -* libgfortran initialization, set_options: _gfortran_set_options. - (line 6) -* libgfortran initialization, set_record_marker: _gfortran_set_record_marker. - (line 6) -* limits, largest number: HUGE. (line 6) -* limits, smallest number: TINY. (line 6) -* LINK: LINK. (line 6) -* linking, static: Link Options. (line 6) -* LLE: LLE. (line 6) -* LLT: LLT. (line 6) -* LNBLNK: LNBLNK. (line 6) -* LOC: LOC. (line 6) -* location of a variable in memory: LOC. (line 6) -* LOG: LOG. (line 6) -* LOG10: LOG10. (line 6) -* logarithm function: LOG. (line 6) -* logarithm function with base 10: LOG10. (line 6) -* logarithm function, inverse: EXP. (line 6) -* LOGICAL: LOGICAL. (line 6) -* logical and, bitwise: AND. (line 6) -* logical and, bitwise <1>: IAND. (line 6) -* logical exclusive or, bitwise: IEOR. (line 6) -* logical exclusive or, bitwise <1>: XOR. (line 6) -* logical not, bitwise: NOT. (line 6) -* logical or, bitwise: IOR. (line 6) -* logical or, bitwise <1>: OR. (line 6) -* logical, variable representation: Internal representation of LOGICAL variables. - (line 6) -* login name: GETLOG. (line 6) -* LOG_GAMMA: LOG_GAMMA. (line 6) -* LONG: LONG. (line 6) -* LSHIFT: LSHIFT. (line 6) -* LSTAT: LSTAT. (line 6) -* LTIME: LTIME. (line 6) -* MALLOC: MALLOC. (line 6) -* mask, left justified: MASKL. (line 6) -* mask, right justified: MASKR. (line 6) -* MASKL: MASKL. (line 6) -* MASKR: MASKR. (line 6) -* MATMUL: MATMUL. (line 6) -* matrix multiplication: MATMUL. (line 6) -* matrix, transpose: TRANSPOSE. (line 6) -* MAX: MAX. (line 6) -* MAX0: MAX. (line 6) -* MAX1: MAX. (line 6) -* MAXEXPONENT: MAXEXPONENT. (line 6) -* maximum value: MAX. (line 6) -* maximum value <1>: MAXVAL. (line 6) -* MAXLOC: MAXLOC. (line 6) -* MAXVAL: MAXVAL. (line 6) -* MCLOCK: MCLOCK. (line 6) -* MCLOCK8: MCLOCK8. (line 6) -* memory checking: Code Gen Options. (line 142) -* MERGE: MERGE. (line 6) -* MERGE_BITS: MERGE_BITS. (line 6) -* messages, error: Error and Warning Options. - (line 6) -* messages, warning: Error and Warning Options. - (line 6) -* MIN: MIN. (line 6) -* MIN0: MIN. (line 6) -* MIN1: MIN. (line 6) -* MINEXPONENT: MINEXPONENT. (line 6) -* minimum value: MIN. (line 6) -* minimum value <1>: MINVAL. (line 6) -* MINLOC: MINLOC. (line 6) -* MINVAL: MINVAL. (line 6) -* Mixed-language programming: Mixed-Language Programming. - (line 6) -* MOD: MOD. (line 6) -* model representation, base: RADIX. (line 6) -* model representation, epsilon: EPSILON. (line 6) -* model representation, largest number: HUGE. (line 6) -* model representation, maximum exponent: MAXEXPONENT. (line 6) -* model representation, minimum exponent: MINEXPONENT. (line 6) -* model representation, precision: PRECISION. (line 6) -* model representation, radix: RADIX. (line 6) -* model representation, range: RANGE. (line 6) -* model representation, significant digits: DIGITS. (line 6) -* model representation, smallest number: TINY. (line 6) -* module entities: Fortran Dialect Options. - (line 52) -* module search path: Directory Options. (line 14) -* module search path <1>: Directory Options. (line 29) -* module search path <2>: Directory Options. (line 36) -* MODULO: MODULO. (line 6) -* modulo: MODULO. (line 6) -* MOVE_ALLOC: MOVE_ALLOC. (line 6) -* moving allocation: MOVE_ALLOC. (line 6) -* multiply array elements: PRODUCT. (line 6) -* MVBITS: MVBITS. (line 6) -* Namelist: Extensions to namelist. - (line 6) -* natural logarithm function: LOG. (line 6) -* NEAREST: NEAREST. (line 6) -* newline: NEW_LINE. (line 6) -* NEW_LINE: NEW_LINE. (line 6) -* NINT: NINT. (line 6) -* norm, Euclidean: NORM2. (line 6) -* NORM2: NORM2. (line 6) -* NOT: NOT. (line 6) -* NULL: NULL. (line 6) -* NUM_IMAGES: NUM_IMAGES. (line 6) -* OpenMP: Fortran Dialect Options. - (line 90) -* OpenMP <1>: OpenMP. (line 6) -* operators, unary: Unary operators. (line 6) -* options inquiry function: COMPILER_OPTIONS. (line 6) -* options, code generation: Code Gen Options. (line 6) -* options, debugging: Debugging Options. (line 6) -* options, dialect: Fortran Dialect Options. - (line 6) -* options, directory search: Directory Options. (line 6) -* options, errors: Error and Warning Options. - (line 6) -* options, Fortran dialect: Fortran Dialect Options. - (line 11) -* options, 'gfortran' command: Invoking GNU Fortran. - (line 6) -* options, linking: Link Options. (line 6) -* options, negative forms: Invoking GNU Fortran. - (line 13) -* options, preprocessor: Preprocessing Options. - (line 6) -* options, real kind type promotion: Fortran Dialect Options. - (line 148) -* options, run-time: Code Gen Options. (line 6) -* options, runtime: Runtime Options. (line 6) -* options, warnings: Error and Warning Options. - (line 6) -* OR: OR. (line 6) -* output, newline: NEW_LINE. (line 6) -* PACK: PACK. (line 6) -* PARITY: PARITY. (line 6) -* Parity: PARITY. (line 6) -* parity: POPPAR. (line 6) -* paths, search: Directory Options. (line 14) -* paths, search <1>: Directory Options. (line 29) -* paths, search <2>: Directory Options. (line 36) -* PERROR: PERROR. (line 6) -* pointer checking: Code Gen Options. (line 142) -* pointer, C address of pointers: C_F_PROCPOINTER. (line 6) -* pointer, C address of procedures: C_FUNLOC. (line 6) -* pointer, C association status: C_ASSOCIATED. (line 6) -* pointer, convert C to Fortran: C_F_POINTER. (line 6) -* pointer, Cray: Cray pointers. (line 6) -* pointer, cray: FREE. (line 6) -* pointer, cray <1>: MALLOC. (line 6) -* pointer, disassociated: NULL. (line 6) -* pointer, status: ASSOCIATED. (line 6) -* pointer, status <1>: NULL. (line 6) -* POPCNT: POPCNT. (line 6) -* POPPAR: POPPAR. (line 6) -* positive difference: DIM. (line 6) -* PRECISION: PRECISION. (line 6) -* Preprocessing: Preprocessing and conditional compilation. - (line 6) -* preprocessing, assertion: Preprocessing Options. - (line 113) -* preprocessing, assertion <1>: Preprocessing Options. - (line 119) -* preprocessing, define macros: Preprocessing Options. - (line 151) -* preprocessing, define macros <1>: Preprocessing Options. - (line 154) -* preprocessing, include path: Preprocessing Options. - (line 69) -* preprocessing, include path <1>: Preprocessing Options. - (line 76) -* preprocessing, include path <2>: Preprocessing Options. - (line 80) -* preprocessing, include path <3>: Preprocessing Options. - (line 85) -* preprocessing, include path <4>: Preprocessing Options. - (line 89) -* preprocessing, include path <5>: Preprocessing Options. - (line 96) -* preprocessing, keep comments: Preprocessing Options. - (line 122) -* preprocessing, keep comments <1>: Preprocessing Options. - (line 137) -* preprocessing, no linemarkers: Preprocessing Options. - (line 179) -* preprocessing, undefine macros: Preprocessing Options. - (line 185) -* preprocessor: Preprocessing Options. - (line 6) -* preprocessor, debugging: Preprocessing Options. - (line 26) -* preprocessor, debugging <1>: Preprocessing Options. - (line 35) -* preprocessor, debugging <2>: Preprocessing Options. - (line 41) -* preprocessor, debugging <3>: Preprocessing Options. - (line 44) -* preprocessor, debugging <4>: Preprocessing Options. - (line 51) -* preprocessor, disable: Preprocessing Options. - (line 12) -* preprocessor, enable: Preprocessing Options. - (line 12) -* preprocessor, include file handling: Preprocessing and conditional compilation. - (line 6) -* preprocessor, working directory: Preprocessing Options. - (line 55) -* PRESENT: PRESENT. (line 6) -* private: Fortran Dialect Options. - (line 52) -* procedure pointer, convert C to Fortran: C_LOC. (line 6) -* process ID: GETPID. (line 6) -* PRODUCT: PRODUCT. (line 6) -* product, double-precision: DPROD. (line 6) -* product, matrix: MATMUL. (line 6) -* product, vector: DOT_PRODUCT. (line 6) -* program termination: EXIT. (line 6) -* program termination, with core dump: ABORT. (line 6) -* 'PROTECTED' statement: Fortran 2003 status. (line 114) -* 'Q' exponent-letter: 'Q' exponent-letter. (line 6) -* RADIX: RADIX. (line 6) -* radix, real: SELECTED_REAL_KIND. (line 6) -* RAN: RAN. (line 6) -* RAND: RAND. (line 6) -* random number generation: IRAND. (line 6) -* random number generation <1>: RAN. (line 6) -* random number generation <2>: RAND. (line 6) -* random number generation <3>: RANDOM_NUMBER. (line 6) -* random number generation, seeding: RANDOM_SEED. (line 6) -* random number generation, seeding <1>: SRAND. (line 6) -* RANDOM_NUMBER: RANDOM_NUMBER. (line 6) -* RANDOM_SEED: RANDOM_SEED. (line 6) -* RANGE: RANGE. (line 6) -* range checking: Code Gen Options. (line 142) -* RANK: RANK. (line 6) -* rank: RANK. (line 6) -* re-association of parenthesized expressions: Code Gen Options. - (line 325) -* read character, stream mode: FGET. (line 6) -* read character, stream mode <1>: FGETC. (line 6) -* REAL: REAL. (line 6) -* real kind: SELECTED_REAL_KIND. (line 6) -* real number, exponent: EXPONENT. (line 6) -* real number, fraction: FRACTION. (line 6) -* real number, nearest different: NEAREST. (line 6) -* real number, relative spacing: RRSPACING. (line 6) -* real number, relative spacing <1>: SPACING. (line 6) -* real number, scale: SCALE. (line 6) -* real number, set exponent: SET_EXPONENT. (line 6) -* Reallocate the LHS in assignments: Code Gen Options. (line 334) -* Reallocate the LHS in assignments, notification: Error and Warning Options. - (line 208) -* REALPART: REAL. (line 6) -* 'RECORD': STRUCTURE and RECORD. - (line 6) -* Reduction, XOR: PARITY. (line 6) -* remainder: MOD. (line 6) -* RENAME: RENAME. (line 6) -* repacking arrays: Code Gen Options. (line 244) -* REPEAT: REPEAT. (line 6) -* RESHAPE: RESHAPE. (line 6) -* right shift, combined: DSHIFTR. (line 6) -* root: SQRT. (line 6) -* rounding, ceiling: ANINT. (line 6) -* rounding, ceiling <1>: CEILING. (line 6) -* rounding, floor: AINT. (line 6) -* rounding, floor <1>: FLOOR. (line 6) -* rounding, nearest whole number: NINT. (line 6) -* RRSPACING: RRSPACING. (line 6) -* RSHIFT: RSHIFT. (line 6) -* run-time checking: Code Gen Options. (line 142) -* SAME_TYPE_AS: SAME_TYPE_AS. (line 6) -* 'SAVE' statement: Code Gen Options. (line 15) -* SCALE: SCALE. (line 6) -* SCAN: SCAN. (line 6) -* search path: Directory Options. (line 6) -* search paths, for included files: Directory Options. (line 14) -* SECNDS: SECNDS. (line 6) -* SECOND: SECOND. (line 6) -* seeding a random number generator: RANDOM_SEED. (line 6) -* seeding a random number generator <1>: SRAND. (line 6) -* SELECTED_CHAR_KIND: SELECTED_CHAR_KIND. (line 6) -* SELECTED_INT_KIND: SELECTED_INT_KIND. (line 6) -* SELECTED_REAL_KIND: SELECTED_REAL_KIND. (line 6) -* SET_EXPONENT: SET_EXPONENT. (line 6) -* SHAPE: SHAPE. (line 6) -* shift, left: DSHIFTL. (line 6) -* shift, left <1>: SHIFTL. (line 6) -* shift, right: DSHIFTR. (line 6) -* shift, right <1>: SHIFTR. (line 6) -* shift, right with fill: SHIFTA. (line 6) -* SHIFTA: SHIFTA. (line 6) -* SHIFTL: SHIFTL. (line 6) -* SHIFTR: SHIFTR. (line 6) -* SHORT: INT2. (line 6) -* SIGN: SIGN. (line 6) -* sign copying: SIGN. (line 6) -* SIGNAL: SIGNAL. (line 6) -* SIN: SIN. (line 6) -* sine: SIN. (line 6) -* sine, hyperbolic: SINH. (line 6) -* sine, hyperbolic, inverse: ASINH. (line 6) -* sine, inverse: ASIN. (line 6) -* SINH: SINH. (line 6) -* SIZE: SIZE. (line 6) -* size of a variable, in bits: BIT_SIZE. (line 6) -* size of an expression: C_SIZEOF. (line 6) -* size of an expression <1>: SIZEOF. (line 6) -* SIZEOF: SIZEOF. (line 6) -* SLEEP: SLEEP. (line 6) -* SNGL: REAL. (line 6) -* SPACING: SPACING. (line 6) -* SPREAD: SPREAD. (line 6) -* SQRT: SQRT. (line 6) -* square-root: SQRT. (line 6) -* SRAND: SRAND. (line 6) -* Standards: Standards. (line 6) -* STAT: STAT. (line 6) -* statement, 'ENUM': Fortran 2003 status. (line 93) -* statement, 'ENUMERATOR': Fortran 2003 status. (line 93) -* statement, 'FLUSH': Fortran 2003 status. (line 89) -* statement, 'IMPORT': Fortran 2003 status. (line 120) -* statement, 'ISO_FORTRAN_ENV': Fortran 2003 status. (line 128) -* statement, 'PROTECTED': Fortran 2003 status. (line 114) -* statement, 'SAVE': Code Gen Options. (line 15) -* statement, 'USE, INTRINSIC': Fortran 2003 status. (line 128) -* statement, 'VALUE': Fortran 2003 status. (line 116) -* statement, 'VOLATILE': Fortran 2003 status. (line 118) -* storage size: STORAGE_SIZE. (line 6) -* STORAGE_SIZE: STORAGE_SIZE. (line 6) -* 'STREAM' I/O: Fortran 2003 status. (line 103) -* stream mode, read character: FGET. (line 6) -* stream mode, read character <1>: FGETC. (line 6) -* stream mode, write character: FPUT. (line 6) -* stream mode, write character <1>: FPUTC. (line 6) -* string, adjust left: ADJUSTL. (line 6) -* string, adjust right: ADJUSTR. (line 6) -* string, comparison: LGE. (line 6) -* string, comparison <1>: LGT. (line 6) -* string, comparison <2>: LLE. (line 6) -* string, comparison <3>: LLT. (line 6) -* string, concatenate: REPEAT. (line 6) -* string, find missing set: VERIFY. (line 6) -* string, find non-blank character: LNBLNK. (line 6) -* string, find subset: SCAN. (line 6) -* string, find substring: INDEX intrinsic. (line 6) -* string, length: LEN. (line 6) -* string, length, without trailing whitespace: LEN_TRIM. (line 6) -* string, remove trailing whitespace: TRIM. (line 6) -* string, repeat: REPEAT. (line 6) -* strings, varying length: Varying Length Character Strings. - (line 6) -* 'STRUCTURE': STRUCTURE and RECORD. - (line 6) -* structure packing: Code Gen Options. (line 238) -* subscript checking: Code Gen Options. (line 142) -* substring position: INDEX intrinsic. (line 6) -* SUM: SUM. (line 6) -* sum array elements: SUM. (line 6) -* suppressing warnings: Error and Warning Options. - (line 6) -* symbol names: Fortran Dialect Options. - (line 34) -* symbol names, transforming: Code Gen Options. (line 54) -* symbol names, transforming <1>: Code Gen Options. (line 111) -* symbol names, underscores: Code Gen Options. (line 54) -* symbol names, underscores <1>: Code Gen Options. (line 111) -* SYMLNK: SYMLNK. (line 6) -* syntax checking: Error and Warning Options. - (line 33) -* SYSTEM: SYSTEM. (line 6) -* system, error handling: GERROR. (line 6) -* system, error handling <1>: IERRNO. (line 6) -* system, error handling <2>: PERROR. (line 6) -* system, group ID: GETGID. (line 6) -* system, host name: HOSTNM. (line 6) -* system, login name: GETLOG. (line 6) -* system, process ID: GETPID. (line 6) -* system, signal handling: SIGNAL. (line 6) -* system, system call: EXECUTE_COMMAND_LINE. - (line 6) -* system, system call <1>: SYSTEM. (line 6) -* system, terminal: ISATTY. (line 6) -* system, terminal <1>: TTYNAM. (line 6) -* system, user ID: GETUID. (line 6) -* system, working directory: CHDIR. (line 6) -* system, working directory <1>: GETCWD. (line 6) -* SYSTEM_CLOCK: SYSTEM_CLOCK. (line 6) -* tabulators: Error and Warning Options. - (line 168) -* TAN: TAN. (line 6) -* tangent: TAN. (line 6) -* tangent, hyperbolic: TANH. (line 6) -* tangent, hyperbolic, inverse: ATANH. (line 6) -* tangent, inverse: ATAN. (line 6) -* tangent, inverse <1>: ATAN2. (line 6) -* TANH: TANH. (line 6) -* terminate program: EXIT. (line 6) -* terminate program, with core dump: ABORT. (line 6) -* THIS_IMAGE: THIS_IMAGE. (line 6) -* thread-safety, threads: Thread-safety of the runtime library. - (line 6) -* TIME: TIME. (line 6) -* time, clock ticks: MCLOCK. (line 6) -* time, clock ticks <1>: MCLOCK8. (line 6) -* time, clock ticks <2>: SYSTEM_CLOCK. (line 6) -* time, conversion to GMT info: GMTIME. (line 6) -* time, conversion to local time info: LTIME. (line 6) -* time, conversion to string: CTIME. (line 6) -* time, current: DATE_AND_TIME. (line 6) -* time, current <1>: FDATE. (line 6) -* time, current <2>: ITIME. (line 6) -* time, current <3>: TIME. (line 6) -* time, current <4>: TIME8. (line 6) -* time, elapsed: CPU_TIME. (line 6) -* time, elapsed <1>: DTIME. (line 6) -* time, elapsed <2>: ETIME. (line 6) -* time, elapsed <3>: SECNDS. (line 6) -* time, elapsed <4>: SECOND. (line 6) -* TIME8: TIME8. (line 6) -* TINY: TINY. (line 6) -* TR 15581: Fortran 2003 status. (line 98) -* trace: Debugging Options. (line 61) -* TRAILZ: TRAILZ. (line 6) -* TRANSFER: TRANSFER. (line 6) -* transforming symbol names: Code Gen Options. (line 54) -* transforming symbol names <1>: Code Gen Options. (line 111) -* TRANSPOSE: TRANSPOSE. (line 6) -* transpose: TRANSPOSE. (line 6) -* trigonometric function, cosine: COS. (line 6) -* trigonometric function, cosine, inverse: ACOS. (line 6) -* trigonometric function, sine: SIN. (line 6) -* trigonometric function, sine, inverse: ASIN. (line 6) -* trigonometric function, tangent: TAN. (line 6) -* trigonometric function, tangent, inverse: ATAN. (line 6) -* trigonometric function, tangent, inverse <1>: ATAN2. (line 6) -* TRIM: TRIM. (line 6) -* TTYNAM: TTYNAM. (line 6) -* type cast: TRANSFER. (line 6) -* UBOUND: UBOUND. (line 6) -* UCOBOUND: UCOBOUND. (line 6) -* UMASK: UMASK. (line 6) -* underflow: Error and Warning Options. - (line 176) -* underscore: Code Gen Options. (line 54) -* underscore <1>: Code Gen Options. (line 111) -* UNLINK: UNLINK. (line 6) -* UNPACK: UNPACK. (line 6) -* unused dummy argument: Error and Warning Options. - (line 187) -* unused parameter: Error and Warning Options. - (line 191) -* 'USE, INTRINSIC' statement: Fortran 2003 status. (line 128) -* user id: GETUID. (line 6) -* 'VALUE' statement: Fortran 2003 status. (line 116) -* Varying length character strings: Varying Length Character Strings. - (line 6) -* Varying length strings: Varying Length Character Strings. - (line 6) -* vector product: DOT_PRODUCT. (line 6) -* VERIFY: VERIFY. (line 6) -* version of the compiler: COMPILER_VERSION. (line 6) -* 'VOLATILE': Volatile COMMON blocks. - (line 6) -* 'VOLATILE' statement: Fortran 2003 status. (line 118) -* warning, C binding type: Error and Warning Options. - (line 99) -* warnings, aliasing: Error and Warning Options. - (line 69) -* warnings, alignment of 'COMMON' blocks: Error and Warning Options. - (line 198) -* warnings, all: Error and Warning Options. - (line 61) -* warnings, ampersand: Error and Warning Options. - (line 86) -* warnings, array temporaries: Error and Warning Options. - (line 94) -* warnings, character truncation: Error and Warning Options. - (line 106) -* warnings, conversion: Error and Warning Options. - (line 113) -* warnings, conversion <1>: Error and Warning Options. - (line 117) -* warnings, extra: Error and Warning Options. - (line 120) -* warnings, function elimination: Error and Warning Options. - (line 204) -* warnings, implicit interface: Error and Warning Options. - (line 125) -* warnings, implicit procedure: Error and Warning Options. - (line 131) -* warnings, intrinsic: Error and Warning Options. - (line 180) -* warnings, intrinsics of other standards: Error and Warning Options. - (line 135) -* warnings, line truncation: Error and Warning Options. - (line 109) -* warnings, non-standard intrinsics: Error and Warning Options. - (line 135) -* warnings, 'q' exponent-letter: Error and Warning Options. - (line 142) -* warnings, suppressing: Error and Warning Options. - (line 6) -* warnings, suspicious code: Error and Warning Options. - (line 146) -* warnings, tabs: Error and Warning Options. - (line 168) -* warnings, to errors: Error and Warning Options. - (line 237) -* warnings, underflow: Error and Warning Options. - (line 176) -* warnings, unused dummy argument: Error and Warning Options. - (line 187) -* warnings, unused parameter: Error and Warning Options. - (line 191) -* write character, stream mode: FPUT. (line 6) -* write character, stream mode <1>: FPUTC. (line 6) -* XOR: XOR. (line 6) -* XOR reduction: PARITY. (line 6) -* ZABS: ABS. (line 6) -* ZCOS: COS. (line 6) -* zero bits: LEADZ. (line 6) -* zero bits <1>: TRAILZ. (line 6) -* ZEXP: EXP. (line 6) -* ZLOG: LOG. (line 6) -* ZSIN: SIN. (line 6) -* ZSQRT: SQRT. (line 6) - - - -Tag Table: -Node: Top1950 -Node: Introduction3337 -Node: About GNU Fortran4086 -Node: GNU Fortran and GCC8075 -Node: Preprocessing and conditional compilation10189 -Node: GNU Fortran and G7711834 -Node: Project Status12407 -Node: Standards14853 -Node: Varying Length Character Strings15863 -Node: Invoking GNU Fortran16615 -Node: Option Summary18338 -Node: Fortran Dialect Options21744 -Node: Preprocessing Options30410 -Node: Error and Warning Options38651 -Node: Debugging Options48848 -Node: Directory Options52316 -Node: Link Options53751 -Node: Runtime Options54377 -Node: Code Gen Options56284 -Node: Environment Variables72491 -Node: Runtime73096 -Node: TMPDIR74196 -Node: GFORTRAN_STDIN_UNIT74866 -Node: GFORTRAN_STDOUT_UNIT75248 -Node: GFORTRAN_STDERR_UNIT75649 -Node: GFORTRAN_UNBUFFERED_ALL76051 -Node: GFORTRAN_UNBUFFERED_PRECONNECTED76582 -Node: GFORTRAN_SHOW_LOCUS77226 -Node: GFORTRAN_OPTIONAL_PLUS77722 -Node: GFORTRAN_DEFAULT_RECL78198 -Node: GFORTRAN_LIST_SEPARATOR78686 -Node: GFORTRAN_CONVERT_UNIT79295 -Node: GFORTRAN_ERROR_BACKTRACE82150 -Node: Fortran 2003 and 2008 status82707 -Node: Fortran 2003 status82967 -Node: Fortran 2008 status88193 -Node: TS 29113 status93042 -Node: Compiler Characteristics94019 -Node: KIND Type Parameters94555 -Node: Internal representation of LOGICAL variables95983 -Node: Thread-safety of the runtime library96843 -Node: Data consistency and durability98270 -Node: Extensions101324 -Node: Extensions implemented in GNU Fortran101929 -Node: Old-style kind specifications103286 -Node: Old-style variable initialization104388 -Node: Extensions to namelist105700 -Node: X format descriptor without count field108003 -Node: Commas in FORMAT specifications108530 -Node: Missing period in FORMAT specifications109047 -Node: I/O item lists109609 -Node: 'Q' exponent-letter109996 -Node: BOZ literal constants110596 -Node: Real array indices113177 -Node: Unary operators113476 -Node: Implicitly convert LOGICAL and INTEGER values113890 -Node: Hollerith constants support114849 -Node: Cray pointers116621 -Node: CONVERT specifier122068 -Node: OpenMP124063 -Node: Argument list functions126314 -Node: Extensions not implemented in GNU Fortran127919 -Node: STRUCTURE and RECORD128868 -Node: ENCODE and DECODE statements131305 -Node: Variable FORMAT expressions132665 -Node: Alternate complex function syntax133770 -Node: Volatile COMMON blocks134320 -Node: Mixed-Language Programming134797 -Node: Interoperability with C135378 -Node: Intrinsic Types136712 -Node: Derived Types and struct137708 -Node: Interoperable Global Variables139066 -Node: Interoperable Subroutines and Functions140341 -Node: Working with Pointers144135 -Node: Further Interoperability of Fortran with C148611 -Node: GNU Fortran Compiler Directives151965 -Node: Non-Fortran Main Program155217 -Node: _gfortran_set_args157405 -Node: _gfortran_set_options158343 -Node: _gfortran_set_convert161743 -Node: _gfortran_set_record_marker162611 -Node: _gfortran_set_fpe163421 -Node: _gfortran_set_max_subrecord_length164619 -Node: Naming and argument-passing conventions165542 -Node: Naming conventions166261 -Node: Argument passing conventions167733 -Node: Intrinsic Procedures172227 -Node: Introduction to Intrinsics187713 -Node: ABORT190063 -Node: ABS190808 -Node: ACCESS192410 -Node: ACHAR194340 -Node: ACOS195544 -Node: ACOSH196798 -Node: ADJUSTL197793 -Node: ADJUSTR198735 -Node: AIMAG199683 -Node: AINT201055 -Node: ALARM202661 -Node: ALL204293 -Node: ALLOCATED206217 -Node: AND207356 -Node: ANINT208655 -Node: ANY210152 -Node: ASIN212078 -Node: ASINH213321 -Node: ASSOCIATED214326 -Node: ATAN217337 -Node: ATAN2218755 -Node: ATANH220547 -Node: ATOMIC_DEFINE221555 -Node: ATOMIC_REF222631 -Node: BACKTRACE223893 -Node: BESSEL_J0224473 -Node: BESSEL_J1225530 -Node: BESSEL_JN226591 -Node: BESSEL_Y0228416 -Node: BESSEL_Y1229426 -Node: BESSEL_YN230436 -Node: BGE232267 -Node: BGT232959 -Node: BIT_SIZE233609 -Node: BLE234431 -Node: BLT235113 -Node: BTEST235751 -Node: C_ASSOCIATED236636 -Node: C_F_POINTER237847 -Node: C_F_PROCPOINTER239282 -Node: C_FUNLOC240789 -Node: C_LOC242160 -Node: C_SIZEOF243439 -Node: CEILING244852 -Node: CHAR245860 -Node: CHDIR247072 -Node: CHMOD248246 -Node: CMPLX250161 -Node: COMMAND_ARGUMENT_COUNT251614 -Node: COMPILER_OPTIONS252530 -Node: COMPILER_VERSION253556 -Node: COMPLEX254520 -Node: CONJG255659 -Node: COS256715 -Node: COSH258139 -Node: COUNT259321 -Node: CPU_TIME261344 -Node: CSHIFT262701 -Node: CTIME264361 -Node: DATE_AND_TIME266007 -Node: DBLE268487 -Node: DCMPLX269282 -Node: DIGITS270464 -Node: DIM271431 -Node: DOT_PRODUCT272712 -Node: DPROD274355 -Node: DREAL275282 -Node: DSHIFTL275948 -Node: DSHIFTR277281 -Node: DTIME278615 -Node: EOSHIFT281430 -Node: EPSILON283503 -Node: ERF284230 -Node: ERFC285011 -Node: ERFC_SCALED285821 -Node: ETIME286514 -Node: EXECUTE_COMMAND_LINE288762 -Node: EXIT291349 -Node: EXP292225 -Node: EXPONENT293476 -Node: EXTENDS_TYPE_OF294238 -Node: FDATE295094 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