diff --git a/lib/CodeGen/DeadMachineInstructionElim.cpp b/lib/CodeGen/DeadMachineInstructionElim.cpp index a3bba61e4a2..8b9cf05d675 100644 --- a/lib/CodeGen/DeadMachineInstructionElim.cpp +++ b/lib/CodeGen/DeadMachineInstructionElim.cpp @@ -64,7 +64,8 @@ bool DeadMachineInstructionElim::runOnMachineFunction(MachineFunction &MF) { const MachineOperand &MO = MI->getOperand(i); if (MO.isRegister() && MO.isDef()) { unsigned Reg = MO.getReg(); - if (TargetRegisterInfo::isPhysicalRegister(Reg) || + if ((!MO.isImplicit() && + TargetRegisterInfo::isPhysicalRegister(Reg)) || !MRI.use_empty(Reg)) { // This def has a use. Don't delete the instruction! AllDefsDead = false;