; Options for the language- and target-independent parts of the compiler. ; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 ; Free Software Foundation, Inc. ; ; This file is part of GCC. ; ; GCC is free software; you can redistribute it and/or modify it under ; the terms of the GNU General Public License as published by the Free ; Software Foundation; either version 3, or (at your option) any later ; version. ; ; GCC is distributed in the hope that it will be useful, but WITHOUT ANY ; WARRANTY; without even the implied warranty of MERCHANTABILITY or ; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ; for more details. ; ; You should have received a copy of the GNU General Public License ; along with GCC; see the file COPYING3. If not see ; . ; See the GCC internals manual (options.texi) for a description of this file's format. ; Please try to keep this file in ASCII collating order. -help Common Display this information -help= Common Report Joined --help= Display descriptions of a specific class of options. is one or more of optimizers, target, warnings, undocumented, params -target-help Common Alias for --help=target ;; The following four entries are to work around the gcc driver ;; program's insatiable desire to turn options starting with a ;; double dash (--) into options starting with a dash f (-f). fhelp Common Var(help_flag) fhelp= Common Joined ftarget-help Common fversion Common -param Common Separate --param = Set parameter to value. See below for a complete list of parameters -version Common G Common Joined Separate UInteger -G Put global and static data smaller than bytes into a special section (on some targets) O Common JoinedOrMissing Optimization -O Set optimization level to Os Common Optimization Optimize for space rather than speed W Common RejectNegative This switch is deprecated; use -Wextra instead Waggregate-return Common Var(warn_aggregate_return) Warning Warn about returning structures, unions or arrays Warray-bounds Common Var(warn_array_bounds) Warning Warn if an array is accessed out of bounds Wattributes Common Var(warn_attributes) Init(1) Warning Warn about inappropriate attribute usage Wcast-align Common Var(warn_cast_align) Warning Warn about pointer casts which increase alignment Wdeprecated-declarations Common Var(warn_deprecated_decl) Init(1) Warning Warn about uses of __attribute__((deprecated)) declarations Wdisabled-optimization Common Var(warn_disabled_optimization) Warning Warn when an optimization pass is disabled Werror Common Var(warnings_are_errors) Treat all warnings as errors Werror= Common Joined Treat specified warning as error Wextra Common Warning Print extra (possibly unwanted) warnings Wfatal-errors Common Var(flag_fatal_errors) Exit on the first error occurred Wframe-larger-than= Common RejectNegative Joined UInteger -Wframe-larger-than= Warn if a function's stack frame requires more than bytes Winline Common Var(warn_inline) Warning Warn when an inlined function cannot be inlined Wlarger-than- Common RejectNegative Joined UInteger Warning Wlarger-than= Common RejectNegative Joined UInteger Warning -Wlarger-than= Warn if an object is larger than bytes Wlogical-op Common Warning Var(warn_logical_op) Warn when a logical operator is suspicously always evaluating to true or false Wunsafe-loop-optimizations Common Var(warn_unsafe_loop_optimizations) Warning Warn if the loop cannot be optimized due to nontrivial assumptions. Wmissing-noreturn Common Var(warn_missing_noreturn) Warning Warn about functions which might be candidates for __attribute__((noreturn)) Wmudflap Common Var(warn_mudflap) Init(1) Warning Warn about constructs not instrumented by -fmudflap Woverflow Common Var(warn_overflow) Init(1) Warning Warn about overflow in arithmetic expressions Wpacked Common Var(warn_packed) Warning Warn when the packed attribute has no effect on struct layout Wpadded Common Var(warn_padded) Warning Warn when padding is required to align structure members Wripa-opt-mismatch Common Var(warn_ripa_opt_mismatch) Warning Warn if primary and auxiliary modules have mismatched command line options Wself-assign Common Var(warn_self_assign) Init(0) Warning Warn when a variable is assigned to itself Wshadow Common Var(warn_shadow) Warning Warn when one local variable shadows another Wshadow-local Common Var(warn_shadow_local) Warning Warn when one local variable shadows another local variable or parameter Wshadow-compatible-local Common Var(warn_shadow_compatible_local) Warning Warn when one local variable shadows another local variable or parameter of compatible type Wstack-protector Common Var(warn_stack_protect) Warning Warn when not issuing stack smashing protection for some reason Wstrict-aliasing Common Warning Warn about code which might break strict aliasing rules Wstrict-aliasing= Common Joined UInteger Var(warn_strict_aliasing) Init(-1) Warning Warn about code which might break strict aliasing rules Wstrict-overflow Common Warning Warn about optimizations that assume that signed overflow is undefined Wstrict-overflow= Common Joined UInteger Var(warn_strict_overflow) Init(-1) Warning Warn about optimizations that assume that signed overflow is undefined Wswitch Common Var(warn_switch) Warning Warn about enumerated switches, with no default, missing a case Wswitch-default Common Var(warn_switch_default) Warning Warn about enumerated switches missing a \"default:\" statement Wswitch-enum Common Var(warn_switch_enum) Warning Warn about all enumerated switches missing a specific case Wsystem-headers Common Var(warn_system_headers) Warning Do not suppress warnings from system headers Wthread-safety Common Var(warn_thread_safety) Warning Warn about potential thread safety issues when the code is annotated with thread safety attributes Wthread-unguarded-var Common Var(warn_thread_unguarded_var) Init(1) Warning Warn about shared variables not properly protected by locks specified in the attributes Wthread-unguarded-func Common Var(warn_thread_unguarded_func) Init(1) Warning Warn about function calls not properly protected by locks specified in the attributes Wthread-mismatched-lock-order Common Var(warn_thread_mismatched_lock_order) Init(1) Warning Warn about lock acquisition order inconsistent with what specified in the attributes Wthread-mismatched-lock-acq-rel Common Var(warn_thread_mismatched_lock_acq_rel) Init(1) Warning Warn about mismatched lock acquisition and release Wthread-reentrant-lock Common Var(warn_thread_reentrant_lock) Init(1) Warning Warn about a lock being acquired recursively Wthread-unsupported-lock-name Common Var(warn_unsupported_lock_name) Init(0) Warning Warn about uses of unsupported lock names in attributes Wtype-limits Common Var(warn_type_limits) Init(-1) Warning Warn if a comparison is always true or always false due to the limited range of the data type Wuninitialized Common Var(warn_uninitialized) Warning Warn about uninitialized automatic variables Wmaybe-uninitialized Common Var(warn_maybe_uninitialized) Warning Warn about maybe uninitialized automatic variables Wunreachable-code Common Var(warn_notreached) Warning Warn about code that will never be executed Wunused Common Var(warn_unused) Init(0) Warning Enable all -Wunused- warnings Wunused-function Common Var(warn_unused_function) Init(-1) Warning Warn when a function is unused Wunused-label Common Var(warn_unused_label) Init(-1) Warning Warn when a label is unused Wunused-parameter Common Var(warn_unused_parameter) Init(-1) Warning Warn when a function parameter is unused Wunused-value Common Var(warn_unused_value) Init(-1) Warning Warn when an expression value is unused Wunused-variable Common Var(warn_unused_variable) Init(-1) Warning Warn when a variable is unused Wcoverage-mismatch Common Var(warn_coverage_mismatch) Init(1) Warning Warn in case profiles in -fprofile-use do not match aux-info Common Separate -aux-info Emit declaration information into aux-info= Common Joined auxbase Common Separate auxbase-strip Common Separate d Common Joined -d Enable dumps from specific passes of the compiler dumpbase Common Separate -dumpbase Set the file basename to be used for dumps ; The version of the C++ ABI in use. The following values are allowed: ; ; 0: The version of the ABI believed most conformant with the C++ ABI ; specification. This ABI may change as bugs are discovered and fixed. ; Therefore, 0 will not necessarily indicate the same ABI in different ; versions of G++. ; ; 1: The version of the ABI first used in G++ 3.2. ; ; 2: The version of the ABI first used in G++ 3.4. ; ; Additional positive integers will be assigned as new versions of ; the ABI become the default version of the ABI. fabi-version= Common Joined UInteger Var(flag_abi_version) Init(2) falign-functions Common Report Var(align_functions,0) Optimization UInteger Align the start of functions falign-functions= Common RejectNegative Joined UInteger falign-jumps Common Report Var(align_jumps,0) Optimization UInteger Align labels which are only reached by jumping falign-jumps= Common RejectNegative Joined UInteger falign-labels Common Report Var(align_labels,0) Optimization UInteger Align all labels falign-labels= Common RejectNegative Joined UInteger falign-loops Common Report Var(align_loops) Optimization UInteger Align the start of loops falign-loops= Common RejectNegative Joined UInteger ; This flag is only tested if alias checking is enabled. ; 0 if pointer arguments may alias each other. True in C. ; 1 if pointer arguments may not alias each other but may alias ; global variables. ; 2 if pointer arguments may not alias each other and may not ; alias global variables. ; 3 if pointer arguments may not alias anything. True in Fortran. ; Set by the front end. fargument-alias Common Report Var(flag_argument_noalias,0) Optimization Specify that arguments may alias each other and globals fargument-noalias Common Report Var(flag_argument_noalias,1) VarExists Optimization Assume arguments may alias globals but not each other fargument-noalias-global Common Report Var(flag_argument_noalias,2) VarExists Optimization Assume arguments alias neither each other nor globals fargument-noalias-anything Common Report Var(flag_argument_noalias,3) VarExists Optimization Assume arguments alias no other storage fasynchronous-unwind-tables Common Report Var(flag_asynchronous_unwind_tables) Optimization Generate unwind tables that are exact at each instruction boundary fauto-inc-dec Common Report Var(flag_auto_inc_dec) Init(1) Generate auto-inc/dec instructions ; -fcheck-bounds causes gcc to generate array bounds checks. ; For C, C++ and ObjC: defaults off. ; For Java: defaults to on. ; For Fortran: defaults to off. fbounds-check Common Report Var(flag_bounds_check) Generate code to check bounds before indexing arrays fbranch-count-reg Common Report Var(flag_branch_on_count_reg) Init(1) Optimization Replace add, compare, branch with branch on count register fbranch-probabilities Common Report Var(flag_branch_probabilities) Optimization Use profiling information for branch probabilities fbranch-target-load-optimize Common Report Var(flag_branch_target_load_optimize) Optimization Perform branch target load optimization before prologue / epilogue threading fbranch-target-load-optimize2 Common Report Var(flag_branch_target_load_optimize2) Optimization Perform branch target load optimization after prologue / epilogue threading fbtr-bb-exclusive Common Report Var(flag_btr_bb_exclusive) Optimization Restrict target load migration not to re-use registers in any basic block fcall-saved- Common Joined RejectNegative -fcall-saved- Mark as being preserved across functions fcall-used- Common Joined RejectNegative -fcall-used- Mark as being corrupted by function calls ; Nonzero for -fcaller-saves: allocate values in regs that need to ; be saved across function calls, if that produces overall better code. ; Optional now, so people can test it. fcaller-saves Common Report Var(flag_caller_saves) Optimization Save registers around function calls fcgraph-section Common Report Var(flag_cgraph_section) Init(0) Generate .note.callgraph.text sections listing callees and edge counts. fcheck-data-deps Common Report Var(flag_check_data_deps) Compare the results of several data dependence analyzers. fcommon Common Report Var(flag_no_common,0) Optimization Do not put uninitialized globals in the common section fconserve-stack Common Var(flag_conserve_stack) Optimization Do not perform optimizations increasing noticeably stack usage fcprop-registers Common Report Var(flag_cprop_registers) Optimization Perform a register copy-propagation optimization pass fcrossjumping Common Report Var(flag_crossjumping) Optimization Perform cross-jumping optimization fcse-follow-jumps Common Report Var(flag_cse_follow_jumps) Optimization When running CSE, follow jumps to their targets fcse-skip-blocks Common Report Var(flag_cse_skip_blocks) Optimization When running CSE, follow conditional jumps fcx-limited-range Common Report Var(flag_cx_limited_range) Optimization Omit range reduction step when performing complex division fcx-fortran-rules Common Report Var(flag_cx_fortran_rules) Optimization Complex multiplication and division follow Fortran rules fdata-sections Common Report Var(flag_data_sections) Optimization Place data items into their own section fdbg-cnt-list Common Report List all available debugging counters with their limits and counts. fdbg-cnt= Common RejectNegative Joined -fdbg-cnt=:[,:,...] Set the debug counter limit. fdebug-prefix-map= Common Joined RejectNegative Map one directory name to another in debug information ; Nonzero for -fdefer-pop: don't pop args after each function call ; instead save them up to pop many calls' args with one insns. fdefer-pop Common Report Var(flag_defer_pop) Optimization Defer popping functions args from stack until later fdelayed-branch Common Report Var(flag_delayed_branch) Optimization Attempt to fill delay slots of branch instructions fdelete-null-pointer-checks Common Report Var(flag_delete_null_pointer_checks) Optimization Delete useless null pointer checks fdiagnostics-show-location= Common Joined RejectNegative -fdiagnostics-show-location=[once|every-line] How often to emit source location at the beginning of line-wrapped diagnostics fdiagnostics-show-option Common Amend appropriate diagnostic messages with the command line option that controls them fdominance-check Common Report Var(flag_enable_dom_check) Init(0) Optimization Check dominance information consistency after incremental update fdump- Common Joined RejectNegative -fdump- Dump various compiler internals to a file fdump-noaddr Common Report Var(flag_dump_noaddr) Suppress output of addresses in debugging dumps fdump-unnumbered Common Report Var(flag_dump_unnumbered) VarExists Suppress output of instruction numbers, line number notes and addresses in debugging dumps fdwarf2-cfi-asm Common Report Var(flag_dwarf2_cfi_asm) Init(HAVE_GAS_CFI_DIRECTIVE) Enable CFI tables via GAS assembler directives. fprofile-reusedist Common Report Var(flag_profile_reusedist) Profile generation for memory reuse distance. foptimize-locality Common Report Var(flag_optimize_locality) Optimization based on improving memory reference locality. fripa Common Report Var(flag_dyn_ipa) Perform Dynamic Inter-Procedural Analysis. fripa-disallow-asm-modules Common Report Var(flag_ripa_disallow_asm_modules) Don't import an auxiliary module if it contains asm statements fripa-disallow-opt-mismatch Common Report Var(flag_ripa_disallow_opt_mismatch) Don't import an auxiliary module if the command line options mismatch with the primary module fripa-no-promote-always-inline-func Common Report Var(flag_ripa_no_promote_always_inline) Init(0) Don't promote always inline static functions assuming they will be inlined and no copy is needed. fripa-verbose Common Report Var(flag_ripa_verbose) Enable verbose informational messages for LIPO compilation fearly-inlining Common Report Var(flag_early_inlining) Init(1) Optimization Perform early inlining fearly-stack-alloc Common Report Var(flag_early_stack_alloc) Make stack coalescing decisions earlier feliminate-dwarf2-dups Common Report Var(flag_eliminate_dwarf2_dups) Perform DWARF2 duplicate elimination feliminate-unused-debug-symbols Common Report Var(flag_debug_only_used_symbols) Perform unused type elimination in debug info feliminate-unused-debug-types Common Report Var(flag_eliminate_unused_debug_types) Init(1) Perform unused type elimination in debug info femit-class-debug-always Common Report Var(flag_emit_class_debug_always) Init(0) Do not suppress C++ class debug information. fenable-icf-debug Common Report Var(flag_enable_icf_debug) Generate debug information to support Identical Code Folding (ICF) fexceptions Common Report Var(flag_exceptions) Optimization Enable exception handling fexpensive-optimizations Common Report Var(flag_expensive_optimizations) Optimization Perform a number of minor, expensive optimizations ffast-math Common ffinite-math-only Common Report Var(flag_finite_math_only) Optimization Assume no NaNs or infinities are generated ffixed- Common Joined RejectNegative -ffixed- Mark as being unavailable to the compiler ffloat-store Common Report Var(flag_float_store) Optimization Don't allocate floats and doubles in extended-precision registers fforce-addr Common Does nothing. Preserved for backward compatibility. fforward-propagate Common Report Var(flag_forward_propagate) Optimization Perform a forward propagation pass on RTL ; Nonzero means don't put addresses of constant functions in registers. ; Used for compiling the Unix kernel, where strange substitutions are ; done on the assembly output. ffunction-cse Common Report Var(flag_no_function_cse,0) Allow function addresses to be held in registers ffunction-sections Common Report Var(flag_function_sections) Place each function into its own section fgcse Common Report Var(flag_gcse) Optimization Perform global common subexpression elimination fgcse-lm Common Report Var(flag_gcse_lm) Init(1) Optimization Perform enhanced load motion during global common subexpression elimination fgcse-sm Common Report Var(flag_gcse_sm) Init(0) Optimization Perform store motion after global common subexpression elimination fgcse-las Common Report Var(flag_gcse_las) Init(0) Optimization Perform redundant load after store elimination in global common subexpression elimination fgcse-after-reload Common Report Var(flag_gcse_after_reload) Optimization Perform global common subexpression elimination after register allocation has finished ; This option is not documented yet as its semantics will change. fgraphite Common Report Var(flag_graphite) Enable in and out of Graphite representation floop-strip-mine Common Report Var(flag_loop_strip_mine) Optimization Enable Loop Strip Mining transformation floop-interchange Common Report Var(flag_loop_interchange) Optimization Enable Loop Interchange transformation floop-block Common Report Var(flag_loop_block) Optimization Enable Loop Blocking transformation ; This option is not documented as it does not perform any useful optimization. fgraphite-identity Common Report Var(flag_graphite_identity) Optimization Enable Graphite Identity transformation fguess-branch-probability Common Report Var(flag_guess_branch_prob) Optimization Enable guessing of branch probabilities ; Nonzero means ignore `#ident' directives. 0 means handle them. ; Generate position-independent code for executables if possible ; On SVR4 targets, it also controls whether or not to emit a ; string identifying the compiler. fident Common Report Var(flag_no_ident,0) Process #ident directives fif-conversion Common Report Var(flag_if_conversion) Optimization Perform conversion of conditional jumps to branchless equivalents fif-conversion2 Common Report Var(flag_if_conversion2) Optimization Perform conversion of conditional jumps to conditional execution ; -finhibit-size-directive inhibits output of .size for ELF. ; This is used only for compiling crtstuff.c, ; and it may be extended to other effects ; needed for crtstuff.c on other systems. finhibit-size-directive Common Report Var(flag_inhibit_size_directive) Do not generate .size directives findirect-inlining Common Report Var(flag_indirect_inlining) Perform indirect inlining ; Nonzero means that functions declared `inline' will be treated ; as `static'. Prevents generation of zillions of copies of unused ; static inline functions; instead, `inlines' are written out ; only when actually used. Used in conjunction with -g. Also ; does the right thing with #pragma interface. finline Common Report Var(flag_no_inline,0) Init(0) Pay attention to the \"inline\" keyword finline-small-functions Common Report Var(flag_inline_small_functions) Optimization Integrate simple functions into their callers when code size is known to not growth finline-functions Common Report Var(flag_inline_functions) Optimization Integrate simple functions into their callers finline-functions-called-once Common Report Var(flag_inline_functions_called_once) Init(1) Optimization Integrate functions called once into their callers finline-limit- Common RejectNegative Joined UInteger finline-limit= Common RejectNegative Joined UInteger -finline-limit= Limit the size of inlined functions to finline-plan- Common Joined RejectNegative -finline-plan-= Apply inlining decisions specified in in inlining pass . finstrument-functions Common Report Var(flag_instrument_function_entry_exit) Instrument function entry and exit with profiling calls finstrument-functions-exclude-function-list= Common RejectNegative Joined -finstrument-functions-exclude-function-list=name,... Do not instrument listed functions finstrument-functions-exclude-file-list= Common RejectNegative Joined -finstrument-functions-exclude-file-list=filename,... Do not instrument functions listed in files fipa-cp Common Report Var(flag_ipa_cp) Optimization Perform Interprocedural constant propagation fipa-cp-clone Common Report Var(flag_ipa_cp_clone) Optimization Perform cloning to make Interprocedural constant propagation stronger fipa-pure-const Common Report Var(flag_ipa_pure_const) Init(0) Optimization Discover pure and const functions fipa-pta Common Report Var(flag_ipa_pta) Init(0) Optimization Perform interprocedural points-to analysis fipa-reference Common Report Var(flag_ipa_reference) Init(0) Optimization Discover readonly and non addressable static variables fipa-type-escape Common Report Var(flag_ipa_type_escape) Init(0) Optimization Type based escape and alias analysis fipa-matrix-reorg Common Report Var(flag_ipa_matrix_reorg) Optimization Perform matrix layout flattening and transposing based on profiling information. fipa-struct-reorg Common Report Var(flag_ipa_struct_reorg) Perform structure layout optimizations based on profiling information. fira-algorithm= Common Joined RejectNegative -fira-algorithm=[CB|priority] Set the used IRA algorithm fira-region= Common Joined RejectNegative -fira-region=[one|all|mixed] Set regions for IRA fira-coalesce Common Report Var(flag_ira_coalesce) Init(0) Do optimistic coalescing. fira-share-save-slots Common Report Var(flag_ira_share_save_slots) Init(1) Share slots for saving different hard registers. fira-share-spill-slots Common Report Var(flag_ira_share_spill_slots) Init(1) Share stack slots for spilled pseudo-registers. fira-verbose= Common RejectNegative Joined UInteger -fira-verbose= Control IRA's level of diagnostic messages. fivopts Common Report Var(flag_ivopts) Init(1) Optimization Optimize induction variables on trees fjump-tables Common Var(flag_jump_tables) Init(1) Optimization Use jump tables for sufficiently large switch statements fkeep-inline-functions Common Report Var(flag_keep_inline_functions) Generate code for functions even if they are fully inlined fkeep-static-consts Common Report Var(flag_keep_static_consts) Init(1) Emit static const variables even if they are not used fleading-underscore Common Report Var(flag_leading_underscore) Init(-1) Give external symbols a leading underscore floop-optimize Common Does nothing. Preserved for backward compatibility. fmath-errno Common Report Var(flag_errno_math) Init(1) Optimization Set errno after built-in math functions fmem-report Common Report Var(mem_report) Report on permanent memory allocation ; This will attempt to merge constant section constants, if 1 only ; string constants and constants from constant pool, if 2 also constant ; variables. fmerge-all-constants Common Report Var(flag_merge_constants,2) Init(1) Optimization Attempt to merge identical constants and constant variables fmerge-constants Common Report Var(flag_merge_constants,1) VarExists Optimization Attempt to merge identical constants across compilation units fmerge-debug-strings Common Report Var(flag_merge_debug_strings) Init(1) Attempt to merge identical debug strings across compilation units fmessage-length= Common RejectNegative Joined UInteger -fmessage-length= Limit diagnostics to characters per line. 0 suppresses line-wrapping fmodulo-sched Common Report Var(flag_modulo_sched) Optimization Perform SMS based modulo scheduling before the first scheduling pass fmodulo-sched-allow-regmoves Common Report Var(flag_modulo_sched_allow_regmoves) Perform SMS based modulo scheduling with register moves allowed flimit-hot-components Common Report Var(flag_limit_hot_components) Optimization Init(0) Limit the size of hot components of the call graph to reduce I-cache pressure fmove-loop-invariants Common Report Var(flag_move_loop_invariants) Init(1) Optimization Move loop invariant computations out of loops fmudflap Common RejectNegative Report Var(flag_mudflap) Add mudflap bounds-checking instrumentation for single-threaded program fmudflapth Common RejectNegative Report VarExists Var(flag_mudflap,2) Add mudflap bounds-checking instrumentation for multi-threaded program fmudflapir Common RejectNegative Report Var(flag_mudflap_ignore_reads) Ignore read operations when inserting mudflap instrumentation fdce Common Var(flag_dce) Init(1) Optimization Use the RTL dead code elimination pass fdse Common Var(flag_dse) Init(1) Optimization Use the RTL dead store elimination pass freschedule-modulo-scheduled-loops Common Report Var(flag_resched_modulo_sched) Optimization Enable/Disable the traditional scheduling in loops that already passed modulo scheduling fnon-call-exceptions Common Report Var(flag_non_call_exceptions) Optimization Support synchronous non-call exceptions fomit-frame-pointer Common Report Var(flag_omit_frame_pointer) Optimization When possible do not generate stack frames foptimize-register-move Common Report Var(flag_regmove) Optimization Do the full register move optimization pass foptimize-sibling-calls Common Report Var(flag_optimize_sibling_calls) Optimization Optimize sibling and tail recursive calls fpre-ipa-mem-report Common Report Var(pre_ipa_mem_report) Report on memory allocation before interprocedural optimization fpost-ipa-mem-report Common Report Var(post_ipa_mem_report) Report on memory allocation before interprocedural optimization fpack-struct Common Report Var(flag_pack_struct) Optimization Pack structure members together without holes fpack-struct= Common RejectNegative Joined UInteger Optimization -fpack-struct= Set initial maximum structure member alignment fpcc-struct-return Common Report Var(flag_pcc_struct_return,1) VarExists Return small aggregates in memory, not registers fpeel-loops Common Report Var(flag_peel_loops) Optimization Perform loop peeling fpeephole Common Report Var(flag_no_peephole,0) Optimization Enable machine specific peephole optimizations fpeephole2 Common Report Var(flag_peephole2) Optimization Enable an RTL peephole pass before sched2 fpessimistic-inline-stack-limit Common Report Var(flag_pessimistic_inline_stack_limit) Init(1) Optimization Assume no stack reuse for locals when computing frame size during inlining fPIC Common Report Var(flag_pic,2) Generate position-independent code if possible (large mode) fPIE Common Report Var(flag_pie,2) Generate position-independent code for executables if possible (large mode) fpic Common Report Var(flag_pic,1) VarExists Generate position-independent code if possible (small mode) fpie Common Report Var(flag_pie,1) VarExists Generate position-independent code for executables if possible (small mode) fplugin= Common Joined RejectNegative Specify a plugin to load fplugin-arg- Common Joined RejectNegative -fplugin-arg--[=] Specify argument = for plugin fpredictive-commoning Common Report Var(flag_predictive_commoning) Optimization Run predictive commoning optimization. fprefetch-loop-arrays Common Report Var(flag_prefetch_loop_arrays) Optimization Generate prefetch instructions, if available, for arrays in loops fprofile Common Report Var(profile_flag) Enable basic program profiling code fprofile-arcs Common Report Var(profile_arc_flag) Insert arc-based program profiling code fprofile-correction Common Report Var(flag_profile_correction) Enable correction of flow inconsistent profile data input fprofile-dir= Common Joined RejectNegative Set the top-level directory for storing the profile data. The default is 'pwd'. fprofile-dump Common Report Var(flag_profile_dump) Init(0) Optimization Dump CFG profile for comparison. fprofile-generate Common Enable common options for generating profile info for profile feedback directed optimizations fprofile-generate= Common Joined RejectNegative Enable common options for generating profile info for profile feedback directed optimizations, and set -fprofile-dir= fprofile-generate-sampling Common Var(flag_profile_generate_sampling) Turn on instrumentation sampling with -fprofile-generate with rate set by --param profile-generate-sampling-rate or environment variable GCOV_SAMPLING_RATE fprofile-use Common Var(flag_profile_use) Enable common options for performing profile feedback directed optimizations fprofile-use= Common Joined RejectNegative Enable common options for performing profile feedback directed optimizations, and set -fprofile-dir= fprofile-values Common Report Var(flag_profile_values) Insert code to profile values of expressions frandom-seed Common frandom-seed= Common Joined RejectNegative -frandom-seed= Make compile reproducible using ; This switch causes the command line that was used to create an ; object file to be recorded into the object file. The exact format ; of this recording is target and binary file format dependent. ; It is related to the -fverbose-asm switch, but that switch only ; records information in the assembler output file as comments, so ; they never reach the object file. frecord-gcc-switches Common Report Var(flag_record_gcc_switches) Record gcc command line switches in the object file. freg-struct-return Common Report Var(flag_pcc_struct_return,0) VarExists Optimization Return small aggregates in registers fregmove Common Report Var(flag_regmove) Optimization Enables a register move optimization frename-registers Common Report Var(flag_rename_registers) Init(2) Optimization Perform a register renaming optimization pass freorder-blocks Common Report Var(flag_reorder_blocks) Optimization Reorder basic blocks to improve code placement freorder-blocks-and-partition Common Report Var(flag_reorder_blocks_and_partition) Optimization Reorder basic blocks and partition into hot and cold sections freorder-functions Common Report Var(flag_reorder_functions) Optimization Reorder functions to improve code placement frerun-cse-after-loop Common Report Var(flag_rerun_cse_after_loop) Init(2) Optimization Add a common subexpression elimination pass after loop optimizations frerun-loop-opt Common Does nothing. Preserved for backward compatibility. frounding-math Common Report Var(flag_rounding_math) Optimization Disable optimizations that assume default FP rounding behavior fpmu-profile-generate= Common Joined RejectNegative Var(flag_pmu_profile_generate) -fpmu-profile-generate=[load-latency] Generate pmu profile for cache misses. Currently only pfmon based load latency profiling is supported on Intel/PEBS and AMD/IBS platforms. fpmu-profile-use= Common Joined RejectNegative Var(flag_pmu_profile_use) -fpmu-profile-use=[load-latency] Use pmu profile data while optimizing. Currently only perfmon based load latency profiling is supported on Intel/PEBS and AMD/IBS platforms. fsample-profile Common Report Var(flag_sample_profile) Optimization Use sample profile information for branch probabilities. The default sample file is sp.data in 'pwd'. fsample-profile= Common Joined RejectNegative Use sample profile information for branch probabilities. The sample file is specified in the argument. fsample-profile-aggregate-using= Common Joined RejectNegative -fsample-profile-aggregate-using=[avg|max] Use the maximum or average number of samples across all instructions in a basic block as the basic block weight fsample-profile-use-entry Common Report Var(flag_sample_profile_use_entry) Init(0) Optimization Use the entry count to annotate the entry basic block frecord-options-in-elf Common Report Var(flag_record_options_in_elf) Init(0) Optimization Record the command line options in the .note elf section for sample FDO to do module grouping fsched-interblock Common Report Var(flag_schedule_interblock) Init(1) Optimization Enable scheduling across basic blocks fsched-spec Common Report Var(flag_schedule_speculative) Init(1) Optimization Allow speculative motion of non-loads fsched-spec-load Common Report Var(flag_schedule_speculative_load) Optimization Allow speculative motion of some loads fsched-spec-load-dangerous Common Report Var(flag_schedule_speculative_load_dangerous) Optimization Allow speculative motion of more loads fsched-verbose= Common RejectNegative Joined -fsched-verbose= Set the verbosity level of the scheduler fsched2-use-superblocks Common Report Var(flag_sched2_use_superblocks) Optimization If scheduling post reload, do superblock scheduling fsched2-use-traces Common Report Var(flag_sched2_use_traces) Optimization If scheduling post reload, do trace scheduling fschedule-insns Common Report Var(flag_schedule_insns) Optimization Reschedule instructions before register allocation fschedule-insns2 Common Report Var(flag_schedule_insns_after_reload) Optimization Reschedule instructions after register allocation ; This flag should be on when a target implements non-trivial ; scheduling hooks, maybe saving some information for its own sake. ; On IA64, for example, this is used for correct bundling. fselective-scheduling Common Report Var(flag_selective_scheduling) Optimization Schedule instructions using selective scheduling algorithm fselective-scheduling2 Common Report Var(flag_selective_scheduling2) Optimization Run selective scheduling after reload fsel-sched-pipelining Common Report Var(flag_sel_sched_pipelining) Init(0) Optimization Perform software pipelining of inner loops during selective scheduling fsel-sched-pipelining-outer-loops Common Report Var(flag_sel_sched_pipelining_outer_loops) Init(0) Optimization Perform software pipelining of outer loops during selective scheduling fsel-sched-reschedule-pipelined Common Report Var(flag_sel_sched_reschedule_pipelined) Init(0) Optimization Reschedule pipelined regions without pipelining ; sched_stalled_insns means that insns can be moved prematurely from the queue ; of stalled insns into the ready list. fsched-stalled-insns Common Report Var(flag_sched_stalled_insns) Optimization UInteger Allow premature scheduling of queued insns fsched-stalled-insns= Common RejectNegative Joined UInteger -fsched-stalled-insns= Set number of queued insns that can be prematurely scheduled ; sched_stalled_insns_dep controls how many recently scheduled cycles will ; be examined for a dependency on a stalled insn that is candidate for ; premature removal from the queue of stalled insns into the ready list (has ; an effect only if the flag 'sched_stalled_insns' is set). fsched-stalled-insns-dep Common Report Var(flag_sched_stalled_insns_dep,1) Init(1) Optimization UInteger Set dependence distance checking in premature scheduling of queued insns fsched-stalled-insns-dep= Common RejectNegative Joined UInteger -fsched-stalled-insns-dep= Set dependence distance checking in premature scheduling of queued insns fsection-anchors Common Report Var(flag_section_anchors) Optimization Access data in the same section from shared anchor points fsee Common Report Var(flag_see) Init(0) Eliminate redundant sign extensions using LCM. fzee Common Report Var(flag_zee) Init(0) Eliminate redundant zero extensions on targets that support implicit extensions. fshow-column Common C ObjC C++ ObjC++ Report Var(flag_show_column) Init(0) Show column numbers in diagnostics, when available. Default off fsignaling-nans Common Report Var(flag_signaling_nans) Optimization Disable optimizations observable by IEEE signaling NaNs fsigned-zeros Common Report Var(flag_signed_zeros) Init(1) Optimization Disable floating point optimizations that ignore the IEEE signedness of zero fsingle-precision-constant Common Report Var(flag_single_precision_constant) Optimization Convert floating point constants to single precision constants fsplit-ivs-in-unroller Common Report Var(flag_split_ivs_in_unroller) Init(1) Optimization Split lifetimes of induction variables when loops are unrolled fsplit-wide-types Common Report Var(flag_split_wide_types) Optimization Split wide types into independent registers fvariable-expansion-in-unroller Common Report Var(flag_variable_expansion_in_unroller) Optimization Apply variable expansion when loops are unrolled fstack-check= Common Report RejectNegative Joined -fstack-check=[no|generic|specific] Insert stack checking code into the program fstack-check Common Report Insert stack checking code into the program. Same as -fstack-check=specific fstack-limit Common fstack-limit-register= Common RejectNegative Joined -fstack-limit-register= Trap if the stack goes past fstack-limit-symbol= Common RejectNegative Joined -fstack-limit-symbol= Trap if the stack goes past symbol fstack-protector Common Report Var(flag_stack_protect, 1) Use propolice as a stack protection method fstack-protector-all Common Report RejectNegative Var(flag_stack_protect, 2) VarExists Use a stack protection method for every function fstrength-reduce Common Does nothing. Preserved for backward compatibility. ; Nonzero if we should do (language-dependent) alias analysis. ; Typically, this analysis will assume that expressions of certain ; types do not alias expressions of certain other types. Only used ; if alias analysis (in general) is enabled. fstrict-aliasing Common Report Var(flag_strict_aliasing) Optimization Assume strict aliasing rules apply fstrict-overflow Common Report Var(flag_strict_overflow) Treat signed overflow as undefined fsyntax-only Common Report Var(flag_syntax_only) Check for syntax errors, then stop ftest-coverage Common Report Var(flag_test_coverage) Create data files needed by \"gcov\" fthread-jumps Common Report Var(flag_thread_jumps) Optimization Perform jump threading optimizations ftime-report Common Report Var(time_report) Report the time taken by each compiler pass ftls-model= Common Joined RejectNegative -ftls-model=[global-dynamic|local-dynamic|initial-exec|local-exec] Set the default thread-local storage code generation model ftoplevel-reorder Common Report Var(flag_toplevel_reorder) Init(2) Optimization Reorder top level functions, variables, and asms ftracer Common Report Var(flag_tracer) Perform superblock formation via tail duplication ; Zero means that floating-point math operations cannot generate a ; (user-visible) trap. This is the case, for example, in nonstop ; IEEE 754 arithmetic. ftrapping-math Common Report Var(flag_trapping_math) Init(1) Optimization Assume floating-point operations can trap ftrapv Common Report Var(flag_trapv) Optimization Trap for signed overflow in addition, subtraction and multiplication ftree-ccp Common Report Var(flag_tree_ccp) Optimization Enable SSA-CCP optimization on trees ftree-store-ccp Common Does nothing. Preserved for backward compatibility. ftree-ch Common Report Var(flag_tree_ch) Optimization Enable loop header copying on trees ftree-copyrename Common Report Var(flag_tree_copyrename) Optimization Replace SSA temporaries with better names in copies ftree-copy-prop Common Report Var(flag_tree_copy_prop) Optimization Enable copy propagation on trees ftree-store-copy-prop Common Does nothing. Preserved for backward compatibility. ftree-cselim Common Report Var(flag_tree_cselim) Init(2) Optimization Transform condition stores into unconditional ones ftree-switch-conversion Common Report Var(flag_tree_switch_conversion) Optimization Perform conversions of switch initializations. ftree-dce Common Report Var(flag_tree_dce) Optimization Enable SSA dead code elimination optimization on trees ftree-dominator-opts Common Report Var(flag_tree_dom) Optimization Enable dominator optimizations ftree-dse Common Report Var(flag_tree_dse) Optimization Enable dead store elimination ftree-fre Common Report Var(flag_tree_fre) Optimization Enable Full Redundancy Elimination (FRE) on trees ftree-lr-shrinking Common Report Var(flag_tree_lr_shrinking) Optimization Enable Live Range Shrinking optimization ftree-loop-distribution Common Report Var(flag_tree_loop_distribution) Optimization Enable loop distribution on trees ftree-loop-im Common Report Var(flag_tree_loop_im) Init(1) Optimization Enable loop invariant motion on trees ftree-loop-linear Common Report Var(flag_tree_loop_linear) Optimization Enable linear loop transforms on trees ftree-loop-ivcanon Common Report Var(flag_tree_loop_ivcanon) Init(1) Optimization Create canonical induction variables in loops ftree-loop-optimize Common Report Var(flag_tree_loop_optimize) Init(1) Optimization Enable loop optimizations on tree level ftree-parallelize-loops= Common Report Joined UInteger Var(flag_tree_parallelize_loops) Init(1) Enable automatic parallelization of loops ftree-pre Common Report Var(flag_tree_pre) Optimization Enable SSA-PRE optimization on trees ftree-reassoc Common Report Var(flag_tree_reassoc) Init(1) Optimization Enable reassociation on tree level ftree-salias Common Does nothing. Preserved for backward compatibility. ftree-sink Common Report Var(flag_tree_sink) Optimization Enable SSA code sinking on trees ftree-sra Common Report Var(flag_tree_sra) Optimization Perform scalar replacement of aggregates ftree-ter Common Report Var(flag_tree_ter) Init(1) Optimization Replace temporary expressions in the SSA->normal pass ftree-lrs Common Report Var(flag_tree_live_range_split) Optimization Perform live range splitting during the SSA->normal pass ftree-vrp Common Report Var(flag_tree_vrp) Init(0) Optimization Perform Value Range Propagation on trees fstrict-enum-precision Common Report Var(flag_strict_enum_precision) Init(1) Optimization Perform transformations based on enum precision funit-at-a-time Common Report Var(flag_unit_at_a_time) Init(1) Optimization Compile whole compilation unit at a time funroll-loops Common Report Var(flag_unroll_loops) Optimization Perform loop unrolling when iteration count is known funroll-all-loops Common Report Var(flag_unroll_all_loops) Optimization Perform loop unrolling for all loops ; Nonzero means that loop optimizer may assume that the induction variables ; that control loops do not overflow and that the loops with nontrivial ; exit condition are not infinite funsafe-loop-optimizations Common Report Var(flag_unsafe_loop_optimizations) Optimization Allow loop optimizations to assume that the loops behave in normal way fassociative-math Common Report Var(flag_associative_math) Allow optimization for floating-point arithmetic which may change the result of the operation due to rounding. freciprocal-math Common Report Var(flag_reciprocal_math) Same as -fassociative-math for expressions which include division. ; Nonzero means that unsafe floating-point math optimizations are allowed ; for the sake of speed. IEEE compliance is not guaranteed, and operations ; are allowed to assume that their arguments and results are "normal" ; (e.g., nonnegative for SQRT). funsafe-math-optimizations Common Report Var(flag_unsafe_math_optimizations) Optimization Allow math optimizations that may violate IEEE or ISO standards funswitch-loops Common Report Var(flag_unswitch_loops) Optimization Perform loop unswitching funwind-tables Common Report Var(flag_unwind_tables) Optimization Just generate unwind tables for exception handling fuse-ld= Common Joined Undocumented fvar-tracking Common Report Var(flag_var_tracking) VarExists Optimization Perform variable tracking fvar-tracking-uninit Common Report Var(flag_var_tracking_uninit) Optimization Perform variable tracking and also tag variables that are uninitialized ftree-vectorize Common Report Var(flag_tree_vectorize) Optimization Enable loop vectorization on trees fvect-cost-model Common Report Var(flag_vect_cost_model) Optimization Enable use of cost model in vectorization ftree-vect-loop-version Common Report Var(flag_tree_vect_loop_version) Init(1) Optimization Enable loop versioning when doing loop vectorization on trees ftree-vectorizer-verbose= Common RejectNegative Joined -ftree-vectorizer-verbose= Set the verbosity level of the vectorizer ftree-scev-cprop Common Report Var(flag_tree_scev_cprop) Init(1) Optimization Enable copy propagation of scalar-evolution information. ; -fverbose-asm causes extra commentary information to be produced in ; the generated assembly code (to make it more readable). This option ; is generally only of use to those who actually need to read the ; generated assembly code (perhaps while debugging the compiler itself). ; -fno-verbose-asm, the default, causes the extra information ; to not be added and is useful when comparing two assembler files. fverbose-asm Common Report Var(flag_verbose_asm) Add extra commentary to assembler output fvisibility= Common Joined RejectNegative -fvisibility=[default|internal|hidden|protected] Set the default symbol visibility fvpt Common Report Var(flag_value_profile_transformations) Optimization Use expression value profiles in optimizations ffvpt Common Report Var(flag_float_value_profile_transformations) Optimization Enable floating point optimizations based on value profiles. Required both for profile generation and use. ffvpt-functions= Common Joined -ffvpt-functions=[,,...]|all List functions to optimize. fweb Common Report Var(flag_web) Init(2) Optimization Construct webs and split unrelated uses of single variable ftree-builtin-call-dce Common Report Var(flag_tree_builtin_call_dce) Init(0) Optimization Enable conditional dead code elimination for builtin calls fclone-hot-version-paths Common Report Var(flag_clone_hot_version_paths) Init(0) Enable cloning and hoisting of hot multiversioned paths fwhole-program Common Report Var(flag_whole_program) Init(0) Optimization Perform whole program optimizations fwrapv Common Report Var(flag_wrapv) Optimization Assume signed arithmetic overflow wraps around fzero-initialized-in-bss Common Report Var(flag_zero_initialized_in_bss) Init(1) Put zero initialized data in the bss section g Common JoinedOrMissing Generate debug information in default format gcoff Common JoinedOrMissing Negative(gdwarf-2) Generate debug information in COFF format gdwarf-2 Common JoinedOrMissing Negative(gdwarf-4) Generate debug information in DWARF v2 format gdwarf-4 Common JoinedOrMissing Negative(gstabs) Generate debug information in DWARF v4 format (experimental) ggdb Common JoinedOrMissing Generate debug information in default extended format gmlt Common RejectNegative Generate debug information at level 1 with minimal line table gstabs Common JoinedOrMissing Negative(gstabs+) Generate debug information in STABS format gstabs+ Common JoinedOrMissing Negative(gvms) Generate debug information in extended STABS format gno-strict-dwarf Common RejectNegative Var(dwarf_strict,0) Init(-1) Emit DWARF additions beyond selected version gstrict-dwarf Common Report RejectNegative Var(dwarf_strict,1) VarExists Don't emit DWARF additions beyond selected version gvms Common JoinedOrMissing Negative(gxcoff) Generate debug information in VMS format gxcoff Common JoinedOrMissing Negative(gxcoff+) Generate debug information in XCOFF format gxcoff+ Common JoinedOrMissing Negative(gcoff) Generate debug information in extended XCOFF format o Common Joined Separate -o Place output into p Common Var(profile_flag) Enable function profiling pedantic Common Var(pedantic) Issue warnings needed for strict compliance to the standard pedantic-errors Common Like -pedantic but issue them as errors quiet Common Var(quiet_flag) Do not display functions compiled or elapsed time version Common Var(version_flag) Display the compiler's version w Common Var(inhibit_warnings) Suppress warnings shared Common RejectNegative Negative(pie) Create a shared library pie Common RejectNegative Negative(shared) Create a position independent executable ; This comment is to ensure we retain the blank line above.