diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 1ace95f28bb..df0b3566bee 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -538,10 +538,35 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { return ReplaceInstUsesWith(I, Op0); // or X, -1 == -1 - if (ConstantIntegral *RHS = dyn_cast(Op1)) + if (ConstantIntegral *RHS = dyn_cast(Op1)) { if (RHS->isAllOnesValue()) return ReplaceInstUsesWith(I, Op1); + if (Instruction *Op0I = dyn_cast(Op0)) { + // (X & C1) | C2 --> (X | C2) & (C1|C2) + if (Op0I->getOpcode() == Instruction::And && isOnlyUse(Op0)) + if (ConstantInt *Op0CI = dyn_cast(Op0I->getOperand(1))) { + std::string Op0Name = Op0I->getName(); Op0I->setName(""); + Instruction *Or = BinaryOperator::create(Instruction::Or, + Op0I->getOperand(0), RHS, + Op0Name); + InsertNewInstBefore(Or, I); + return BinaryOperator::create(Instruction::And, Or, *RHS | *Op0CI); + } + + // (X ^ C1) | C2 --> (X | C2) ^ (C1&~C2) + if (Op0I->getOpcode() == Instruction::Xor && isOnlyUse(Op0)) + if (ConstantInt *Op0CI = dyn_cast(Op0I->getOperand(1))) { + std::string Op0Name = Op0I->getName(); Op0I->setName(""); + Instruction *Or = BinaryOperator::create(Instruction::Or, + Op0I->getOperand(0), RHS, + Op0Name); + InsertNewInstBefore(Or, I); + return BinaryOperator::create(Instruction::Xor, Or, *Op0CI & *~*RHS); + } + } + } + Value *Op0NotVal = dyn_castNotVal(Op0); Value *Op1NotVal = dyn_castNotVal(Op1);