[InstCombine] allow X / C -> X * (1.0/C) for vector splat FP constants
llvm-svn: 325237
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index 5457f19..57a3055 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -1319,21 +1319,19 @@
/// Try to convert X/C into X * (1/C).
static Instruction *foldFDivConstantDivisor(BinaryOperator &FDiv) {
- // TODO: Handle vector constants.
- ConstantFP *CFP;
- if (!match(FDiv.getOperand(1), m_ConstantFP(CFP)))
+ // TODO: Handle non-splat vector constants.
+ const APFloat *C;
+ if (!match(FDiv.getOperand(1), m_APFloat(C)))
return nullptr;
- const APFloat &FpVal = CFP->getValueAPF();
- APFloat Reciprocal(FpVal.getSemantics());
-
// This returns false if the inverse would be a denormal.
- bool HasRecip = FpVal.getExactInverse(&Reciprocal);
+ APFloat Reciprocal(C->getSemantics());
+ bool HasRecip = C->getExactInverse(&Reciprocal);
// If the inverse is not exact, we may still be able to convert if we are
// not operating with strict math.
- if (!HasRecip && FDiv.hasAllowReciprocal() && FpVal.isFiniteNonZero()) {
- Reciprocal = APFloat(FpVal.getSemantics(), 1.0f);
- Reciprocal.divide(FpVal, APFloat::rmNearestTiesToEven);
+ if (!HasRecip && FDiv.hasAllowReciprocal() && C->isFiniteNonZero()) {
+ Reciprocal = APFloat(C->getSemantics(), 1.0f);
+ Reciprocal.divide(*C, APFloat::rmNearestTiesToEven);
// Disallow denormal constants because we don't know what would happen
// on all targets.
// TODO: Function attributes can tell us that denorms are flushed?
@@ -1343,7 +1341,7 @@
if (!HasRecip)
return nullptr;
- auto *RecipCFP = ConstantFP::get(FDiv.getContext(), Reciprocal);
+ auto *RecipCFP = ConstantFP::get(FDiv.getType(), Reciprocal);
return BinaryOperator::CreateFMul(FDiv.getOperand(0), RecipCFP);
}