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| author | Hans-Peter Nilsson <hp@axis.com> | 2005-03-22 03:48:44 +0000 |
|---|---|---|
| committer | Hans-Peter Nilsson <hp@gcc.gnu.org> | 2005-03-22 03:48:44 +0000 |
| commit | 17c9bcdd2886e8243937d80e45f9315f472a395d (patch) | |
| tree | 49b678c9ba3b7d15c623064be8b7ac677529e32b /gcc/combine.c | |
| parent | 9d7cb254255ee037f4b0852c661a5a5212353d1c (diff) | |
| download | gcc-17c9bcdd2886e8243937d80e45f9315f472a395d.zip gcc-17c9bcdd2886e8243937d80e45f9315f472a395d.tar.gz gcc-17c9bcdd2886e8243937d80e45f9315f472a395d.tar.bz2 | |
re PR rtl-optimization/20527 (Mishandling of postincrement causes bzip2 miscompilation.)
PR rtl-optimization/20527
* combine.c (can_combine_p) [AUTO_INC_DEC]: When INSN has an
REG_INC note, test that the register also isn't mentioned in PRED
or SUCC.
From-SVN: r96853
Diffstat (limited to 'gcc/combine.c')
| -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 5981403..297b58e 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -1314,9 +1314,9 @@ can_combine_p (rtx insn, rtx i3, rtx pred ATTRIBUTE_UNUSED, rtx succ, if (INSN_P (p) && p != succ && volatile_insn_p (PATTERN (p))) return 0; - /* If INSN or I2 contains an autoincrement or autodecrement, - make sure that register is not used between there and I3, - and not already used in I3 either. + /* If INSN contains an autoincrement or autodecrement, make sure that + register is not used between there and I3, and not already used in + I3 either. Neither must it be used in PRED or SUCC, if they exist. Also insist that I3 not be a jump; if it were one and the incremented register were spilled, we would lose. */ @@ -1325,6 +1325,10 @@ can_combine_p (rtx insn, rtx i3, rtx pred ATTRIBUTE_UNUSED, rtx succ, if (REG_NOTE_KIND (link) == REG_INC && (JUMP_P (i3) || reg_used_between_p (XEXP (link, 0), insn, i3) + || (pred != NULL_RTX + && reg_overlap_mentioned_p (XEXP (link, 0), PATTERN (pred))) + || (succ != NULL_RTX + && reg_overlap_mentioned_p (XEXP (link, 0), PATTERN (succ))) || reg_overlap_mentioned_p (XEXP (link, 0), PATTERN (i3)))) return 0; #endif |