diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp index 40d107a810af..27b87425adc1 100644 --- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp @@ -1832,8 +1832,8 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { ConstantInt *C1; Value *X; // (X & C1) | C2 --> (X | C2) & (C1|C2) if (match(Op0, m_And(m_Value(X), m_ConstantInt(C1))) && isOnlyUse(Op0)) { - std::string Op0Name = Op0->getName(); Op0->setName(""); - Instruction *Or = BinaryOperator::createOr(X, RHS, Op0Name); + Instruction *Or = BinaryOperator::createOr(X, RHS, Op0->getName()); + Op0->setName(""); InsertNewInstBefore(Or, I); return BinaryOperator::createAnd(Or, ConstantExpr::getOr(RHS, C1)); } @@ -1865,6 +1865,22 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { if (A == Op0 || B == Op0) // A | (A & ?) --> A return ReplaceInstUsesWith(I, Op0); + // (X^C)|Y -> (X|Y)^C iff Y&C == 0 + if (Op0->hasOneUse() && match(Op0, m_Xor(m_Value(A), m_ConstantInt(C1))) && + MaskedValueIsZero(Op1, C1)) { + Instruction *NOr = BinaryOperator::createOr(A, Op1, Op0->getName()); + Op0->setName(""); + return BinaryOperator::createXor(InsertNewInstBefore(NOr, I), C1); + } + + // Y|(X^C) -> (X|Y)^C iff Y&C == 0 + if (Op1->hasOneUse() && match(Op1, m_Xor(m_Value(A), m_ConstantInt(C1))) && + MaskedValueIsZero(Op0, C1)) { + Instruction *NOr = BinaryOperator::createOr(A, Op0, Op1->getName()); + Op0->setName(""); + return BinaryOperator::createXor(InsertNewInstBefore(NOr, I), C1); + } + // (A & C1)|(A & C2) == A & (C1|C2) if (match(Op0, m_And(m_Value(A), m_ConstantInt(C1))) && match(Op1, m_And(m_Value(B), m_ConstantInt(C2))) && A == B)