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| author | Roger Sayle <roger@eyesopen.com> | 2003-01-23 02:57:26 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2003-01-23 02:57:26 +0000 |
| commit | 34ee7f8278d155d6d128f6af19b10ed35fa8f3d5 (patch) | |
| tree | e350e7cda96af13a3c7a7347f5f121cef549541c /gcc/builtins.c | |
| parent | 94edc4abdc1de8d0c77421354eabf3bfc3de0c91 (diff) | |
| download | gcc-34ee7f8278d155d6d128f6af19b10ed35fa8f3d5.zip gcc-34ee7f8278d155d6d128f6af19b10ed35fa8f3d5.tar.gz gcc-34ee7f8278d155d6d128f6af19b10ed35fa8f3d5.tar.bz2 | |
re PR rtl-optimization/8423 (CSE1 not propagating __builtin_constant_p enough)
PR optimization/8423
* cse.c (fold_rtx): Only eliminate a CONSTANT_P_RTX to 1 when
its argument is constant, or 0 if !flag_gcse.
* simplify-rtx.c (simplify_rtx): Convert CONSTANT_P_RTX to 1
if it's argument is constant.
* gcse.c (want_to_gcse_p): Ignore CONSTANT_P_RTX nodes.
(hash_scan_set): Don't record CONSTANT_P_RTX expressions.
(do_local_cprop): Don't propagate CONSTANT_P_RTX constants.
* builtins.c (purge_builtin_constant_p): New function to force
instantiation of any remaining CONSTANT_P_RTX nodes.
* rtl.h (purge_builtin_constant_p): Prototype here.
* toplev.c (rest_of_compilation): Invoke purge_builtin_constant_p
pass after GCSE and before loop.
(flag_gcse): No longer static.
* flags.h (flag_gcse): Prototype here.
From-SVN: r61642
Diffstat (limited to 'gcc/builtins.c')
| -rw-r--r-- | gcc/builtins.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/gcc/builtins.c b/gcc/builtins.c index ffa09f9..5e72df6 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -1461,8 +1461,8 @@ expand_builtin_constant_p (exp) arglist = TREE_VALUE (arglist); /* We have taken care of the easy cases during constant folding. This - case is not obvious, so emit (constant_p_rtx (ARGLIST)) and let CSE get a - chance to see if it can deduce whether ARGLIST is constant. */ + case is not obvious, so emit (constant_p_rtx (ARGLIST)) and let CSE + get a chance to see if it can deduce whether ARGLIST is constant. */ tmp = expand_expr (arglist, NULL_RTX, VOIDmode, 0); tmp = gen_rtx_CONSTANT_P_RTX (value_mode, tmp); @@ -4496,3 +4496,32 @@ default_expand_builtin (exp, target, subtarget, mode, ignore) { return NULL_RTX; } + +/* Instantiate all remaining CONSTANT_P_RTX nodes. */ + +void +purge_builtin_constant_p () +{ + rtx insn, done, set; + rtx arg, new, note; + basic_block bb; + + FOR_EACH_BB (bb) + { + done = NEXT_INSN (bb->end); + for (insn = bb->head; insn != done; insn = NEXT_INSN (insn)) + if (INSN_P (insn) + && (set = single_set (insn)) != NULL_RTX + && GET_CODE (SET_SRC (set)) == CONSTANT_P_RTX) + { + arg = XEXP (SET_SRC (set), 0); + new = CONSTANT_P (arg) ? const1_rtx : const0_rtx; + validate_change (insn, &SET_SRC (set), new, 0); + + /* Remove the REG_EQUAL note from the insn. */ + if ((note = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0) + remove_note (insn, note); + } + } +} + |