If BB is empty, insert PHI before end() instead of front().

llvm-svn: 90744
This commit is contained in:
Evan Cheng 2009-12-07 03:07:01 +00:00
parent bcd035061d
commit 92c310cb79
1 changed files with 6 additions and 3 deletions

View File

@ -157,8 +157,9 @@ unsigned MachineSSAUpdater::GetValueInMiddleOfBlock(MachineBasicBlock *BB) {
return SingularValue;
// Otherwise, we do need a PHI: insert one now.
MachineBasicBlock::iterator Loc = BB->empty() ? BB->end() : BB->front();
MachineInstr *InsertedPHI = InsertNewDef(TargetInstrInfo::PHI, BB,
BB->front(), VRC, MRI, TII);
Loc, VRC, MRI, TII);
// Fill in all the predecessors of the PHI.
MachineInstrBuilder MIB(InsertedPHI);
@ -231,7 +232,8 @@ unsigned MachineSSAUpdater::GetValueAtEndOfBlockInternal(MachineBasicBlock *BB){
// that we have a cycle. Handle this by inserting a PHI node and returning
// it. When we get back to the first instance of the recursion we will fill
// in the PHI node.
MachineInstr *NewPHI = InsertNewDef(TargetInstrInfo::PHI, BB, BB->front(),
MachineBasicBlock::iterator Loc = BB->empty() ? BB->end() : BB->front();
MachineInstr *NewPHI = InsertNewDef(TargetInstrInfo::PHI, BB, Loc,
VRC, MRI,TII);
unsigned NewVR = NewPHI->getOperand(0).getReg();
InsertRes.first->second = NewVR;
@ -311,7 +313,8 @@ unsigned MachineSSAUpdater::GetValueAtEndOfBlockInternal(MachineBasicBlock *BB){
// Otherwise, we do need a PHI: insert one now if we don't already have one.
MachineInstr *InsertedPHI;
if (InsertedVal == 0) {
InsertedPHI = InsertNewDef(TargetInstrInfo::PHI, BB, BB->front(),
MachineBasicBlock::iterator Loc = BB->empty() ? BB->end() : BB->front();
InsertedPHI = InsertNewDef(TargetInstrInfo::PHI, BB, Loc,
VRC, MRI, TII);
InsertedVal = InsertedPHI->getOperand(0).getReg();
} else {