diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/CodeGen/MachineCSE.cpp | 5 | ||||
| -rw-r--r-- | lib/CodeGen/MachineRegisterInfo.cpp | 9 |
2 files changed, 13 insertions, 1 deletions
diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp index 84c3d717f7..cfe50408e6 100644 --- a/lib/CodeGen/MachineCSE.cpp +++ b/lib/CodeGen/MachineCSE.cpp @@ -112,6 +112,7 @@ bool MachineCSE::PerformTrivialCoalescing(MachineInstr *MI, DEBUG(dbgs() << "Coalescing: " << *DefMI); DEBUG(dbgs() << "*** to: " << *MI); MO.setReg(SrcReg); + MRI->clearKillFlags(SrcReg); if (NewRC != SRC) MRI->setRegClass(SrcReg, NewRC); DefMI->eraseFromParent(); @@ -365,8 +366,10 @@ bool MachineCSE::ProcessBlock(MachineBasicBlock *MBB) { // Actually perform the elimination. if (DoCSE) { - for (unsigned i = 0, e = CSEPairs.size(); i != e; ++i) + for (unsigned i = 0, e = CSEPairs.size(); i != e; ++i) { MRI->replaceRegWith(CSEPairs[i].first, CSEPairs[i].second); + MRI->clearKillFlags(CSEPairs[i].second); + } MI->eraseFromParent(); ++NumCSEs; } else { diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp index 5465fca05f..402be479ea 100644 --- a/lib/CodeGen/MachineRegisterInfo.cpp +++ b/lib/CodeGen/MachineRegisterInfo.cpp @@ -133,6 +133,15 @@ bool MachineRegisterInfo::hasOneNonDBGUse(unsigned RegNo) const { return ++UI == use_nodbg_end(); } +/// clearKillFlags - Iterate over all the uses of the given register and +/// clear the kill flag from the MachineOperand. This function is used by +/// optimization passes which extend register lifetimes and need only +/// preserve conservative kill flag information. +void MachineRegisterInfo::clearKillFlags(unsigned Reg) const { + for (use_iterator UI = use_begin(Reg), UE = use_end(); UI != UE; ++UI) + UI.getOperand().setIsKill(false); +} + bool MachineRegisterInfo::isLiveIn(unsigned Reg) const { for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I) if (I->first == Reg || I->second == Reg) |