Index: include/llvm/CodeGen/MachineInstr.h =================================================================== --- include/llvm/CodeGen/MachineInstr.h +++ include/llvm/CodeGen/MachineInstr.h @@ -685,6 +685,12 @@ /// eraseFromBundle() to erase individual bundled instructions. void eraseFromParent(); + /// Unlink 'this' from the containing basic block and delete it. + /// + /// For all definitions mark their uses in DBG_VALUE nodes + /// as undefined. Otherwise like eraseFromParent(). + void eraseFromParentAndMarkDBGValuesForRemoval(); + /// Unlink 'this' form its basic block and delete it. /// /// If the instruction is part of a bundle, the other instructions in the Index: lib/CodeGen/DeadMachineInstructionElim.cpp =================================================================== --- lib/CodeGen/DeadMachineInstructionElim.cpp +++ lib/CodeGen/DeadMachineInstructionElim.cpp @@ -124,19 +124,10 @@ if (isDead(MI)) { DEBUG(dbgs() << "DeadMachineInstructionElim: DELETING: " << *MI); // It is possible that some DBG_VALUE instructions refer to this - // instruction. Examine each def operand for such references; - // if found, mark the DBG_VALUE as undef (but don't delete it). - for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { - const MachineOperand &MO = MI->getOperand(i); - if (!MO.isReg() || !MO.isDef()) - continue; - unsigned Reg = MO.getReg(); - if (!TargetRegisterInfo::isVirtualRegister(Reg)) - continue; - MRI->markUsesInDebugValueAsUndef(Reg); - } + // instruction. They get marked as undef and will be deleted + // in the live debug variable analysis. + MI->eraseFromParentAndMarkDBGValuesForRemoval(); AnyChanges = true; - MI->eraseFromParent(); ++NumDeletes; MIE = MBB->rend(); // MII is now pointing to the next instruction to process, Index: lib/CodeGen/MachineInstr.cpp =================================================================== --- lib/CodeGen/MachineInstr.cpp +++ lib/CodeGen/MachineInstr.cpp @@ -895,6 +895,27 @@ getParent()->erase(this); } +void MachineInstr::eraseFromParentAndMarkDBGValuesForRemoval() { + assert(getParent() && "Not embedded in a basic block!"); + MachineBasicBlock *MBB = getParent(); + MachineFunction *MF = MBB->getParent(); + assert(MF && "Not embedded in a function!"); + + MachineInstr *MI = (MachineInstr *)this; + MachineRegisterInfo &MRI = MF->getRegInfo(); + + for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { + const MachineOperand &MO = MI->getOperand(i); + if (!MO.isReg() || !MO.isDef()) + continue; + unsigned Reg = MO.getReg(); + if (!TargetRegisterInfo::isVirtualRegister(Reg)) + continue; + MRI.markUsesInDebugValueAsUndef(Reg); + } + MI->eraseFromParent(); +} + void MachineInstr::eraseFromBundle() { assert(getParent() && "Not embedded in a basic block!"); getParent()->erase_instr(this);