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[InstCombine] clean up fdiv-with-fdiv folds; NFCI 

llvm-svn: 325366
This commit is contained in:
Sanjay Patel 2018-02-16 17:52:32 +00:00
parent 870fbda805
commit 91bb775087
1 changed files with 23 additions and 28 deletions
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51
llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
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@ -1426,36 +1426,31 @@ Instruction *InstCombiner::visitFDiv(BinaryOperator &I) {
if (AllowReassociate) {
Value *X, *Y;
Value *NewInst = nullptr;
Instruction *SimpR = nullptr;
if (match(Op0, m_OneUse(m_FDiv(m_Value(X), m_Value(Y))))) {
// (X/Y) / Z => X / (Y*Z)
if (!isa<Constant>(Y) || !isa<Constant>(Op1)) {
NewInst = Builder.CreateFMul(Y, Op1);
if (Instruction *RI = dyn_cast<Instruction>(NewInst)) {
FastMathFlags Flags = I.getFastMathFlags();
Flags &= cast<Instruction>(Op0)->getFastMathFlags();
RI->setFastMathFlags(Flags);
}
SimpR = BinaryOperator::CreateFDiv(X, NewInst);
}
} else if (match(Op1, m_OneUse(m_FDiv(m_Value(X), m_Value(Y))))) {
// Z / (X/Y) => Z*Y / X
if (!isa<Constant>(Y) || !isa<Constant>(Op0)) {
NewInst = Builder.CreateFMul(Op0, Y);
if (Instruction *RI = dyn_cast<Instruction>(NewInst)) {
FastMathFlags Flags = I.getFastMathFlags();
Flags &= cast<Instruction>(Op1)->getFastMathFlags();
RI->setFastMathFlags(Flags);
}
SimpR = BinaryOperator::CreateFDiv(NewInst, X);
if (match(Op0, m_OneUse(m_FDiv(m_Value(X), m_Value(Y)))) &&
(!isa<Constant>(Y) || !isa<Constant>(Op1))) {
// (X / Y) / Z => X / (Y * Z)
Value *YZ = Builder.CreateFMul(Y, Op1);
if (auto *YZInst = dyn_cast<Instruction>(YZ)) {
FastMathFlags FMFIntersect = I.getFastMathFlags();
FMFIntersect &= cast<Instruction>(Op0)->getFastMathFlags();
YZInst->setFastMathFlags(FMFIntersect);
}
Instruction *NewDiv = BinaryOperator::CreateFDiv(X, YZ);
NewDiv->setFastMathFlags(I.getFastMathFlags());
return NewDiv;
}
if (NewInst) {
SimpR->setFastMathFlags(I.getFastMathFlags());
return SimpR;
if (match(Op1, m_OneUse(m_FDiv(m_Value(X), m_Value(Y)))) &&
(!isa<Constant>(Y) || !isa<Constant>(Op0))) {
// Z / (X / Y) => (Y * Z) / X
Value *YZ = Builder.CreateFMul(Y, Op0);
if (auto *YZInst = dyn_cast<Instruction>(YZ)) {
FastMathFlags FMFIntersect = I.getFastMathFlags();
FMFIntersect &= cast<Instruction>(Op1)->getFastMathFlags();
YZInst->setFastMathFlags(FMFIntersect);
}
Instruction *NewDiv = BinaryOperator::CreateFDiv(YZ, X);
NewDiv->setFastMathFlags(I.getFastMathFlags());
return NewDiv;
}
}