diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 6d006b1815d..c409e91ef00 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -1622,6 +1622,19 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) { if (Op1F->getValue() == 1.0) return ReplaceInstUsesWith(I, Op0); // Eliminate 'mul double %X, 1.0' } + + if (BinaryOperator *Op0I = dyn_cast(Op0)) + if (Op0I->getOpcode() == Instruction::Add && Op0I->hasOneUse() && + isa(Op0I->getOperand(1))) { + // Canonicalize (X+C1)*C2 -> X*C2+C1*C2. + Instruction *Add = BinaryOperator::createMul(Op0I->getOperand(0), + Op1, "tmp"); + InsertNewInstBefore(Add, I); + Value *C1C2 = ConstantExpr::getMul(Op1, + cast(Op0I->getOperand(1))); + return BinaryOperator::createAdd(Add, C1C2); + + } // Try to fold constant mul into select arguments. if (SelectInst *SI = dyn_cast(Op0))