Index: lib/CodeGen/TwoAddressInstructionPass.cpp =================================================================== --- lib/CodeGen/TwoAddressInstructionPass.cpp +++ lib/CodeGen/TwoAddressInstructionPass.cpp @@ -483,32 +483,6 @@ return false; } -/// findLocalKill - Look for an instruction below MI in the MBB that kills the -/// specified register. Returns null if there are any other Reg use between the -/// instructions. -static -MachineInstr *findLocalKill(unsigned Reg, MachineBasicBlock *MBB, - MachineInstr *MI, MachineRegisterInfo *MRI, - DenseMap &DistanceMap) { - MachineInstr *KillMI = 0; - for (MachineRegisterInfo::use_nodbg_iterator - UI = MRI->use_nodbg_begin(Reg), - UE = MRI->use_nodbg_end(); UI != UE; ++UI) { - MachineInstr *UseMI = &*UI; - if (UseMI == MI || UseMI->getParent() != MBB) - continue; - if (DistanceMap.count(UseMI)) - continue; - if (!UI.getOperand().isKill()) - return 0; - if (KillMI) - return 0; // -O0 kill markers cannot be trusted? - KillMI = UseMI; - } - - return KillMI; -} - /// findOnlyInterestingUse - Given a register, if has a single in-basic block /// use, return the use instruction if it's a copy or a two-address use. static @@ -905,14 +879,19 @@ MachineBasicBlock::iterator &mi, MachineBasicBlock::iterator &nmi, unsigned Reg) { + // Bail immediately if we don't have LV available. We use it to find kills + // efficiently. + if (!LV) + return false; + MachineInstr *MI = &*mi; DenseMap::iterator DI = DistanceMap.find(MI); if (DI == DistanceMap.end()) // Must be created from unfolded load. Don't waste time trying this. return false; - MachineInstr *KillMI = findLocalKill(Reg, MBB, mi, MRI, DistanceMap); - if (!KillMI || KillMI->isCopy() || KillMI->isCopyLike()) + MachineInstr *KillMI = LV->getVarInfo(Reg).findKill(MBB); + if (!KillMI || MI == KillMI || KillMI->isCopy() || KillMI->isCopyLike()) // Don't mess with copies, they may be coalesced later. return false; @@ -999,6 +978,12 @@ ((MO.isKill() && Uses.count(MOReg)) || Kills.count(MOReg))) // Don't want to extend other live ranges and update kills. return false; + if (MOReg == Reg && !MO.isKill()) + // We can't schedule across a use of the register in question. + return false; + // Ensure that if this is register in question, its the kill we expect. + assert((MOReg != Reg || OtherMI == KillMI) && + "Found multiple kills of a register in a basic block"); } } } @@ -1012,19 +997,9 @@ MBB->splice(KillPos, MBB, From, To); DistanceMap.erase(DI); - if (LV) { - // Update live variables - LV->removeVirtualRegisterKilled(Reg, KillMI); - LV->addVirtualRegisterKilled(Reg, MI); - } else { - for (unsigned i = 0, e = KillMI->getNumOperands(); i != e; ++i) { - MachineOperand &MO = KillMI->getOperand(i); - if (!MO.isReg() || !MO.isUse() || MO.getReg() != Reg) - continue; - MO.setIsKill(false); - } - MI->addRegisterKilled(Reg, 0); - } + // Update live variables + LV->removeVirtualRegisterKilled(Reg, KillMI); + LV->addVirtualRegisterKilled(Reg, MI); return true; } @@ -1061,14 +1036,19 @@ MachineBasicBlock::iterator &mi, MachineBasicBlock::iterator &nmi, unsigned Reg) { + // Bail immediately if we don't have LV available. We use it to find kills + // efficiently. + if (!LV) + return false; + MachineInstr *MI = &*mi; DenseMap::iterator DI = DistanceMap.find(MI); if (DI == DistanceMap.end()) // Must be created from unfolded load. Don't waste time trying this. return false; - MachineInstr *KillMI = findLocalKill(Reg, MBB, mi, MRI, DistanceMap); - if (!KillMI || KillMI->isCopy() || KillMI->isCopyLike()) + MachineInstr *KillMI = LV->getVarInfo(Reg).findKill(MBB); + if (!KillMI || MI == KillMI || KillMI->isCopy() || KillMI->isCopyLike()) // Don't mess with copies, they may be coalesced later. return false; @@ -1094,6 +1074,8 @@ continue; if (isDefTooClose(MOReg, DI->second, MI, MBB)) return false; + if (MOReg == Reg && !MO.isKill()) + return false; Uses.insert(MOReg); if (MO.isKill() && MOReg != Reg) Kills.insert(MOReg); @@ -1135,6 +1117,9 @@ if (Kills.count(MOReg)) // Don't want to extend other live ranges and update kills. return false; + if (OtherMI != MI && MOReg == Reg && !MO.isKill()) + // We can't schedule across a use of the register in question. + return false; } else { OtherDefs.push_back(MOReg); } @@ -1165,19 +1150,10 @@ nmi = llvm::prior(InsertPos); // Backtrack so we process the moved instr. DistanceMap.erase(DI); - if (LV) { - // Update live variables - LV->removeVirtualRegisterKilled(Reg, KillMI); - LV->addVirtualRegisterKilled(Reg, MI); - } else { - for (unsigned i = 0, e = KillMI->getNumOperands(); i != e; ++i) { - MachineOperand &MO = KillMI->getOperand(i); - if (!MO.isReg() || !MO.isUse() || MO.getReg() != Reg) - continue; - MO.setIsKill(false); - } - MI->addRegisterKilled(Reg, 0); - } + // Update live variables + LV->removeVirtualRegisterKilled(Reg, KillMI); + LV->addVirtualRegisterKilled(Reg, MI); + return true; }