- if (MI->getNumOperands() == 2) {
- DEBUG(dbgs() << "Deleting identity copy.\n");
- if (Indexes)
- Indexes->removeMachineInstrFromMaps(MI);
- // It's safe to erase MI because MII has already been incremented.
- MI->eraseFromParent();
- } else {
- // Transform identity copy to a KILL to deal with subregisters.
- MI->setDesc(TII->get(TargetOpcode::KILL));
- DEBUG(dbgs() << "Identity copy: " << *MI);
- }
- }
- }
- }
-
- // Tell MRI about physical registers in use.
- if (NoReturnInsts.empty()) {
- for (SparseSet<unsigned>::iterator
- RegI = PhysRegs.begin(), E = PhysRegs.end(); RegI != E; ++RegI)
- if (!MRI->reg_nodbg_empty(*RegI))
- MRI->setPhysRegUsed(*RegI);
- } else {
- for (SparseSet<unsigned>::iterator
- I = PhysRegs.begin(), E = PhysRegs.end(); I != E; ++I) {
- unsigned Reg = *I;
- if (MRI->reg_nodbg_empty(Reg))
- continue;
- // Check if this register has a use that will impact the rest of the
- // code. Uses in debug and noreturn instructions do not impact the
- // generated code.
- for (MachineRegisterInfo::reg_instr_nodbg_iterator It =
- MRI->reg_instr_nodbg_begin(Reg),
- EndIt = MRI->reg_instr_nodbg_end(); It != EndIt; ++It) {
- if (!NoReturnInsts.count(&(*It))) {
- MRI->setPhysRegUsed(Reg);
- break;
- }