diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp index ccb3d72431d..bbdf2448e64 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -1760,11 +1760,25 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) { } } + auto canMergeSelectThroughBinop = [](BinaryOperator *BO) { + // The select might be preventing a division by 0. + switch (BO->getOpcode()) { + default: + return true; + case Instruction::SRem: + case Instruction::URem: + case Instruction::SDiv: + case Instruction::UDiv: + return false; + } + }; + // Try to simplify a binop sandwiched between 2 selects with the same // condition. // select(C, binop(select(C, X, Y), W), Z) -> select(C, binop(X, W), Z) BinaryOperator *TrueBO; - if (match(TrueVal, m_OneUse(m_BinOp(TrueBO)))) { + if (match(TrueVal, m_OneUse(m_BinOp(TrueBO))) && + canMergeSelectThroughBinop(TrueBO)) { if (auto *TrueBOSI = dyn_cast<SelectInst>(TrueBO->getOperand(0))) { if (TrueBOSI->getCondition() == CondVal) { TrueBO->setOperand(0, TrueBOSI->getTrueValue()); @@ -1783,7 +1797,8 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) { // select(C, Z, binop(select(C, X, Y), W)) -> select(C, Z, binop(Y, W)) BinaryOperator *FalseBO; - if (match(FalseVal, m_OneUse(m_BinOp(FalseBO)))) { + if (match(FalseVal, m_OneUse(m_BinOp(FalseBO))) && + canMergeSelectThroughBinop(FalseBO)) { if (auto *FalseBOSI = dyn_cast<SelectInst>(FalseBO->getOperand(0))) { if (FalseBOSI->getCondition() == CondVal) { FalseBO->setOperand(0, FalseBOSI->getFalseValue()); |
