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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2015-06-16 14:57:29 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2015-06-16 14:57:29 +0000 |
| commit | 1ee59cba5d90841a615d95195a972b3c24c7dc2b (patch) | |
| tree | f2b74d31f940323d066c194663d9e756a617c9a1 /llvm/lib/Analysis | |
| parent | 302275a938141ab1af7b7d73007ae2ad3bc802bc (diff) | |
| download | bcm5719-llvm-1ee59cba5d90841a615d95195a972b3c24c7dc2b.tar.gz bcm5719-llvm-1ee59cba5d90841a615d95195a972b3c24c7dc2b.zip | |
[InstSimplify] Allow folding of fdiv X, X with just NaNs ignored
Any combination of +-inf/+-inf is NaN so it's already ignored with
nnan and we can skip checking for ninf. Also rephrase logic in comments
a bit.
llvm-svn: 239821
Diffstat (limited to 'llvm/lib/Analysis')
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index 8f7a940aa95..12e406bb1a2 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -1126,13 +1126,13 @@ static Value *SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (FMF.noNaNs() && FMF.noSignedZeros() && match(Op0, m_AnyZero())) return Op0; - if (FMF.noNaNs() && FMF.noInfs()) { - // X / X -> 1.0 iff NaNs and infinities are ignored. + if (FMF.noNaNs()) { + // X / X -> 1.0 is legal when NaNs are ignored. if (Op0 == Op1) return ConstantFP::get(Op0->getType(), 1.0); // -X / X -> -1.0 and - // X / -X -> -1.0 iff NaNs and infinities are ignored. + // X / -X -> -1.0 are legal when NaNs are ignored. // We can ignore signed zeros because +-0.0/+-0.0 is NaN and ignored. if ((BinaryOperator::isFNeg(Op0, /*IgnoreZeroSign=*/true) && BinaryOperator::getFNegArgument(Op0) == Op1) || |
