diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp index 92533ffdb4b..78c2d312939 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -3424,6 +3424,24 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { Value *Src1 = II->getArgOperand(1); Value *Src2 = II->getArgOperand(2); + // Checking for NaN before canonicalization provides better fidelity when + // mapping other operations onto fmed3 since the order of operands is + // unchanged. + CallInst *NewCall = nullptr; + if (match(Src0, m_NaN()) || isa<UndefValue>(Src0)) { + NewCall = Builder.CreateMinNum(Src1, Src2); + } else if (match(Src1, m_NaN()) || isa<UndefValue>(Src1)) { + NewCall = Builder.CreateMinNum(Src0, Src2); + } else if (match(Src2, m_NaN()) || isa<UndefValue>(Src2)) { + NewCall = Builder.CreateMaxNum(Src0, Src1); + } + + if (NewCall) { + NewCall->copyFastMathFlags(II); + NewCall->takeName(II); + return replaceInstUsesWith(*II, NewCall); + } + bool Swap = false; // Canonicalize constants to RHS operands. // @@ -3450,13 +3468,6 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { return II; } - if (match(Src2, m_NaN()) || isa<UndefValue>(Src2)) { - CallInst *NewCall = Builder.CreateMinNum(Src0, Src1); - NewCall->copyFastMathFlags(II); - NewCall->takeName(II); - return replaceInstUsesWith(*II, NewCall); - } - if (const ConstantFP *C0 = dyn_cast<ConstantFP>(Src0)) { if (const ConstantFP *C1 = dyn_cast<ConstantFP>(Src1)) { if (const ConstantFP *C2 = dyn_cast<ConstantFP>(Src2)) { |
