diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp index a9b0ea6cbba..fb143c98279 100644 --- a/lib/Transforms/Scalar/Reassociate.cpp +++ b/lib/Transforms/Scalar/Reassociate.cpp @@ -318,16 +318,18 @@ static Value *NegateValue(Value *V, Instruction *BI) { // if (Instruction *I = dyn_cast(V)) if (I->getOpcode() == Instruction::Add && I->hasOneUse()) { - Value *RHS = NegateValue(I->getOperand(1), BI); - Value *LHS = NegateValue(I->getOperand(0), BI); + // Push the negates through the add. + I->setOperand(0, NegateValue(I->getOperand(0), BI)); + I->setOperand(1, NegateValue(I->getOperand(1), BI)); - // We must actually insert a new add instruction here, because the neg - // instructions do not dominate the old add instruction in general. By - // adding it now, we are assured that the neg instructions we just - // inserted dominate the instruction we are about to insert after them. + // We must move the add instruction here, because the neg instructions do + // not dominate the old add instruction in general. By moving it, we are + // assured that the neg instructions we just inserted dominate the + // instruction we are about to insert after them. // - return BinaryOperator::create(Instruction::Add, LHS, RHS, - I->getName()+".neg", BI); + I->moveBefore(BI); + I->setName(I->getName()+".neg"); + return I; } // Insert a 'neg' instruction that subtracts the value from zero to get the