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| author | Richard Kenner <kenner@gcc.gnu.org> | 1993-10-02 14:10:47 -0400 |
|---|---|---|
| committer | Richard Kenner <kenner@gcc.gnu.org> | 1993-10-02 14:10:47 -0400 |
| commit | d81481d3d95364ece0e95fb8d0373bef2e55f50d (patch) | |
| tree | 958c1eba283b70add246dda8245e404336270826 /gcc | |
| parent | 1ddb342ad7b20c56b38ad4319f937d2d62c95841 (diff) | |
| download | gcc-d81481d3d95364ece0e95fb8d0373bef2e55f50d.zip gcc-d81481d3d95364ece0e95fb8d0373bef2e55f50d.tar.gz gcc-d81481d3d95364ece0e95fb8d0373bef2e55f50d.tar.bz2 | |
(can_combine_p): Allow an insn with a REG_EQUIV note that reads memory
to be moved past an insn that writes memory.
From-SVN: r5562
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/combine.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 45d572a..c502656 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -855,10 +855,14 @@ can_combine_p (insn, i3, pred, succ, pdest, psrc) If the insns are adjacent, a use can't cross a set even though we think it might (this can happen for a sequence of insns each setting the same destination; reg_last_set of that register might point to - a NOTE). Also, don't move a volatile asm or UNSPEC_VOLATILE across - any other insns. */ + a NOTE). If INSN has a REG_EQUIV note, the register is always + equivalent to the memory so the substitution is valid even if there + are intervening stores. Also, don't move a volatile asm or + UNSPEC_VOLATILE across any other insns. */ || (! all_adjacent - && (use_crosses_set_p (src, INSN_CUID (insn)) + && (((GET_CODE (src) != MEM + || ! find_reg_note (insn, REG_EQUIV, src)) + && use_crosses_set_p (src, INSN_CUID (insn))) || (GET_CODE (src) == ASM_OPERANDS && MEM_VOLATILE_P (src)) || GET_CODE (src) == UNSPEC_VOLATILE)) /* If there is a REG_NO_CONFLICT note for DEST in I3 or SUCC, we get |