Fix for the original bug in PR5495 - Look at uses as well as defs when determining the PHI-copy insert point.

- Patch by Andrew Canis!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88880 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Lang Hames 2009-11-16 02:00:09 +00:00
parent a44321776e
commit b126d0530d

View File

@ -141,10 +141,10 @@ llvm::PHIElimination::FindCopyInsertPoint(MachineBasicBlock &MBB,
if (!SuccMBB.isLandingPad())
return MBB.getFirstTerminator();
// Discover any definitions in this basic block.
// Discover any defs/uses in this basic block.
SmallPtrSet<MachineInstr*, 8> DefUsesInMBB;
for (MachineRegisterInfo::def_iterator RI = MRI->def_begin(SrcReg),
RE = MRI->def_end(); RI != RE; ++RI) {
for (MachineRegisterInfo::reg_iterator RI = MRI->reg_begin(SrcReg),
RE = MRI->reg_end(); RI != RE; ++RI) {
MachineInstr *DefUseMI = &*RI;
if (DefUseMI->getParent() == &MBB)
DefUsesInMBB.insert(DefUseMI);
@ -155,11 +155,11 @@ llvm::PHIElimination::FindCopyInsertPoint(MachineBasicBlock &MBB,
// No defs. Insert the copy at the start of the basic block.
InsertPoint = MBB.begin();
} else if (DefUsesInMBB.size() == 1) {
// Insert the copy immediately after the def.
// Insert the copy immediately after the def/use.
InsertPoint = *DefUsesInMBB.begin();
++InsertPoint;
} else {
// Insert the copy immediately after the last def.
// Insert the copy immediately after the last def/use.
InsertPoint = MBB.end();
while (!DefUsesInMBB.count(&*--InsertPoint)) {}
++InsertPoint;