diff --git a/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp b/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp index 3c404046f15e..b67f84b0f943 100644 --- a/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp +++ b/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp @@ -909,9 +909,16 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &MF) { } // If it's profitable to commute the instruction, do so. - if (TID.isCommutable() && mi->getNumOperands() >= 3) { - unsigned regC = mi->getOperand(3-si).getReg(); - if (isProfitableToCommute(regB, regC, mi, mbbi, Dist)) + unsigned SrcOp1, SrcOp2; + if (TID.isCommutable() && mi->getNumOperands() >= 3 && + TII->findCommutedOpIndices(mi, SrcOp1, SrcOp2)) { + unsigned regC = 0; + if (si == SrcOp1) + regC = mi->getOperand(SrcOp2).getReg(); + else if (si == SrcOp2) + regC = mi->getOperand(SrcOp1).getReg(); + + if (regC && isProfitableToCommute(regB, regC, mi, mbbi, Dist)) if (CommuteInstruction(mi, mbbi, regB, regC, Dist)) { ++NumAggrCommuted; ++NumCommuted;