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| author | Hans-Peter Nilsson <hp@axis.com> | 2000-04-05 21:14:53 +0000 |
|---|---|---|
| committer | Hans-Peter Nilsson <hp@gcc.gnu.org> | 2000-04-05 21:14:53 +0000 |
| commit | 65945ec1b3c5199a692e477b873cb975285cc515 (patch) | |
| tree | ae42126fedf19fc11979a414c3bc82d0b8ae8029 /gcc/combine.c | |
| parent | 0d0df4fcbf84383855c6682bdbc0d9b5a7bb51df (diff) | |
| download | gcc-65945ec1b3c5199a692e477b873cb975285cc515.zip gcc-65945ec1b3c5199a692e477b873cb975285cc515.tar.gz gcc-65945ec1b3c5199a692e477b873cb975285cc515.tar.bz2 | |
md.texi (Standard Names): Clarify when movX is needed.
* md.texi (Standard Names): Clarify when movX is needed.
* combine.c (simplify_comparison) [MINUS]: Do not replace
all (op (minus A B) 0) with (op A B).
From-SVN: r32940
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 2d46a69..911ebbf 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -10452,13 +10452,10 @@ simplify_comparison (code, pop0, pop1) break; case MINUS: - /* (op (minus A B) 0) -> (op A B) */ - if (op1 == const0_rtx) - { - op1 = XEXP (op0, 1); - op0 = XEXP (op0, 0); - continue; - } + /* We used to optimize signed comparisons against zero, but that + was incorrect. Unsigned comparisons against zero (GTU, LEU) + arrive here as equality comparisons, or (GEU, LTU) are + optimized away. No need to special-case them. */ /* (eq (minus A B) C) -> (eq A (plus B C)) or (eq B (minus A C)), whichever simplifies. We can only do |