diff options
Diffstat (limited to 'llvm/lib/Analysis/InstructionSimplify.cpp')
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index a258c4df898..b81ecc83c05 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -4298,9 +4298,15 @@ static Value *SimplifyFDivInst(Value *Op0, Value *Op1, FastMathFlags FMF, if (FMF.noNaNs()) { // X / X -> 1.0 is legal when NaNs are ignored. + // We can ignore infinities because INF/INF is NaN. if (Op0 == Op1) return ConstantFP::get(Op0->getType(), 1.0); + // (X * Y) / Y --> X if we can reassociate to the above form. + Value *X; + if (FMF.allowReassoc() && match(Op0, m_c_FMul(m_Value(X), m_Specific(Op1)))) + return X; + // -X / X -> -1.0 and // X / -X -> -1.0 are legal when NaNs are ignored. // We can ignore signed zeros because +-0.0/+-0.0 is NaN and ignored. |
