- if (Reg == SuperReg) continue;
-
- DEBUG(errs() << " " << TRI->getName(Reg));
-
- // If Reg is dead and Reg's most recent def is not before
- // SuperRegs's kill, it's safe to replace SuperReg with Reg. We
- // must also check all subregisters of Reg.
- if (State->IsLive(Reg) || (KillIndices[SuperReg] > DefIndices[Reg])) {
- DEBUG(errs() << "(live)");
- continue;
- } else {
- bool found = false;
- for (const unsigned *Subreg = TRI->getSubRegisters(Reg);
- *Subreg; ++Subreg) {
- unsigned SubregReg = *Subreg;
- if (State->IsLive(SubregReg) || (KillIndices[SuperReg] > DefIndices[SubregReg])) {
- DEBUG(errs() << "(subreg " << TRI->getName(SubregReg) << " live)");
- found = true;
- break;
+ if (NewSuperReg == SuperReg) continue;
+
+ DEBUG(dbgs() << " [" << TRI->getName(NewSuperReg) << ':');
+ RenameMap.clear();
+
+ // For each referenced group register (which must be a SuperReg or
+ // a subregister of SuperReg), find the corresponding subregister
+ // of NewSuperReg and make sure it is free to be renamed.
+ for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
+ unsigned Reg = Regs[i];
+ unsigned NewReg = 0;
+ if (Reg == SuperReg) {
+ NewReg = NewSuperReg;
+ } else {
+ unsigned NewSubRegIdx = TRI->getSubRegIndex(SuperReg, Reg);
+ if (NewSubRegIdx != 0)
+ NewReg = TRI->getSubReg(NewSuperReg, NewSubRegIdx);
+ }
+
+ DEBUG(dbgs() << " " << TRI->getName(NewReg));
+
+ // Check if Reg can be renamed to NewReg.
+ BitVector BV = RenameRegisterMap[Reg];
+ if (!BV.test(NewReg)) {
+ DEBUG(dbgs() << "(no rename)");
+ goto next_super_reg;
+ }
+
+ // If NewReg is dead and NewReg's most recent def is not before
+ // Regs's kill, it's safe to replace Reg with NewReg. We
+ // must also check all aliases of NewReg, because we can't define a
+ // register when any sub or super is already live.
+ if (State->IsLive(NewReg) || (KillIndices[Reg] > DefIndices[NewReg])) {
+ DEBUG(dbgs() << "(live)");
+ goto next_super_reg;
+ } else {
+ bool found = false;
+ for (MCRegAliasIterator AI(NewReg, TRI, false); AI.isValid(); ++AI) {
+ unsigned AliasReg = *AI;
+ if (State->IsLive(AliasReg) ||
+ (KillIndices[Reg] > DefIndices[AliasReg])) {
+ DEBUG(dbgs() << "(alias " << TRI->getName(AliasReg) << " live)");
+ found = true;
+ break;
+ }