diff options
Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/rtlhooks.c')
| -rw-r--r-- | gcc-4.2.1-5666.3/gcc/rtlhooks.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/rtlhooks.c b/gcc-4.2.1-5666.3/gcc/rtlhooks.c new file mode 100644 index 000000000..ece7198f9 --- /dev/null +++ b/gcc-4.2.1-5666.3/gcc/rtlhooks.c @@ -0,0 +1,169 @@ +/* Generic hooks for the RTL middle-end. + Copyright (C) 2004, 2005 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 2, 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 COPYING. If not, write to the Free +Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301, USA. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "rtl.h" +#include "rtlhooks-def.h" +#include "expr.h" +#include "recog.h" + + +/* For speed, we will copy the RTX hooks struct member-by-member + instead of doing indirect calls. For these reason, we initialize + *two* struct rtl_hooks globals: rtl_hooks is the one that is used + to actually call the hooks, while general_rtl_hooks is used + to restore the hooks by passes that modify them. */ + +const struct rtl_hooks general_rtl_hooks = RTL_HOOKS_INITIALIZER; +struct rtl_hooks rtl_hooks = RTL_HOOKS_INITIALIZER; + +rtx +gen_lowpart_general (enum machine_mode mode, rtx x) +{ + rtx result = gen_lowpart_common (mode, x); + + if (result) + return result; + /* If it's a REG, it must be a hard reg that's not valid in MODE. */ + else if (REG_P (x) + /* Or we could have a subreg of a floating point value. */ + || (GET_CODE (x) == SUBREG + && FLOAT_MODE_P (GET_MODE (SUBREG_REG (x))))) + { + result = gen_lowpart_common (mode, copy_to_reg (x)); + gcc_assert (result != 0); + return result; + } + else + { + int offset = 0; + + /* The only additional case we can do is MEM. */ + gcc_assert (MEM_P (x)); + + /* The following exposes the use of "x" to CSE. */ + if (GET_MODE_SIZE (GET_MODE (x)) <= UNITS_PER_WORD + && SCALAR_INT_MODE_P (GET_MODE (x)) + && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode), + GET_MODE_BITSIZE (GET_MODE (x))) + && ! no_new_pseudos) + return gen_lowpart_general (mode, force_reg (GET_MODE (x), x)); + + if (WORDS_BIG_ENDIAN) + offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD) + - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD)); + + if (BYTES_BIG_ENDIAN) + /* Adjust the address so that the address-after-the-data + is unchanged. */ + offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)) + - MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x)))); + + return adjust_address (x, mode, offset); + } +} + +/* Similar to gen_lowpart, but cannot emit any instruction via + copy_to_reg or force_reg. Mainly used in simplify-rtx.c. */ +rtx +gen_lowpart_no_emit_general (enum machine_mode mode, rtx x) +{ + rtx result = gen_lowpart_if_possible (mode, x); + if (result) + return result; + else + return x; +} + +rtx +reg_num_sign_bit_copies_general (rtx x ATTRIBUTE_UNUSED, + enum machine_mode mode ATTRIBUTE_UNUSED, + rtx known_x ATTRIBUTE_UNUSED, + enum machine_mode known_mode ATTRIBUTE_UNUSED, + unsigned int known_ret ATTRIBUTE_UNUSED, + unsigned int *result ATTRIBUTE_UNUSED) +{ + return NULL; +} + +rtx +reg_nonzero_bits_general (rtx x ATTRIBUTE_UNUSED, + enum machine_mode mode ATTRIBUTE_UNUSED, + rtx known_x ATTRIBUTE_UNUSED, + enum machine_mode known_mode ATTRIBUTE_UNUSED, + unsigned HOST_WIDE_INT known_ret ATTRIBUTE_UNUSED, + unsigned HOST_WIDE_INT *nonzero ATTRIBUTE_UNUSED) +{ + return NULL; +} + +bool +reg_truncated_to_mode_general (enum machine_mode mode ATTRIBUTE_UNUSED, + rtx x ATTRIBUTE_UNUSED) +{ + return false; +} + +/* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point + number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the + least-significant part of X. + MODE specifies how big a part of X to return. + + If the requested operation cannot be done, 0 is returned. + + This is similar to gen_lowpart_general. */ + +rtx +gen_lowpart_if_possible (enum machine_mode mode, rtx x) +{ + rtx result = gen_lowpart_common (mode, x); + + if (result) + return result; + else if (MEM_P (x)) + { + /* This is the only other case we handle. */ + int offset = 0; + rtx new; + + if (WORDS_BIG_ENDIAN) + offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD) + - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD)); + if (BYTES_BIG_ENDIAN) + /* Adjust the address so that the address-after-the-data is + unchanged. */ + offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)) + - MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x)))); + + new = adjust_address_nv (x, mode, offset); + if (! memory_address_p (mode, XEXP (new, 0))) + return 0; + + return new; + } + else if (mode != GET_MODE (x) && GET_MODE (x) != VOIDmode) + return gen_lowpart_SUBREG (mode, x); + else + return 0; +} + |