diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp | 29 |
1 files changed, 12 insertions, 17 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp index 01b1f4cdf3c..fec6baeb69c 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp @@ -1150,27 +1150,22 @@ static Instruction *foldSelectShuffles(ShuffleVectorInst &Shuf) { !match(Shuf.getOperand(1), m_BinOp(B1))) return nullptr; - // TODO: There are potential folds where the opcodes do not match (mul+shl). - if (B0->getOpcode() != B1->getOpcode()) - return nullptr; - // TODO: Fold the case with different variable operands (requires creating a // new shuffle and checking number of uses). Value *X; Constant *C0, *C1; - if (!match(B0, m_c_BinOp(m_Value(X), m_Constant(C0))) || - !match(B1, m_c_BinOp(m_Specific(X), m_Constant(C1)))) - return nullptr; - - // If all operands are constants, let constant folding remove the binops. - if (isa<Constant>(X)) + bool ConstantsAreOp1; + if (match(B0, m_BinOp(m_Value(X), m_Constant(C0))) && + match(B1, m_BinOp(m_Specific(X), m_Constant(C1)))) + ConstantsAreOp1 = true; + else if (match(B0, m_BinOp(m_Constant(C0), m_Value(X))) && + match(B1, m_BinOp(m_Constant(C1), m_Specific(X)))) + ConstantsAreOp1 = false; + else return nullptr; - // Constant operands must be on the same side of each binop. We can't fold: - // shuffle (sdiv X, C0), (sdiv C1, X). - bool B00IsConst = isa<Constant>(B0->getOperand(0)); - bool B10IsConst = isa<Constant>(B1->getOperand(0)); - if (B00IsConst != B10IsConst) + // TODO: There are potential folds where the opcodes do not match (mul+shl). + if (B0->getOpcode() != B1->getOpcode()) return nullptr; // Remove a binop and the shuffle by rearranging the constant: @@ -1185,8 +1180,8 @@ static Instruction *foldSelectShuffles(ShuffleVectorInst &Shuf) { NewC = getSafeVectorConstantForIntDivRem(NewC); BinaryOperator::BinaryOps Opc = B0->getOpcode(); - Instruction *NewBO = B00IsConst ? BinaryOperator::Create(Opc, NewC, X) : - BinaryOperator::Create(Opc, X, NewC); + Instruction *NewBO = ConstantsAreOp1 ? BinaryOperator::Create(Opc, X, NewC) : + BinaryOperator::Create(Opc, NewC, X); // Flags are intersected from the 2 source binops. NewBO->copyIRFlags(B0); |
