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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!

llvm-svn: 88880
This commit is contained in:
Lang Hames 2009-11-16 02:00:09 +00:00
parent 2496fe14ec
commit 968bd90f88
1 changed files with 5 additions and 5 deletions
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10
llvm/lib/CodeGen/PHIElimination.cpp
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@ -141,10 +141,10 @@ llvm::PHIElimination::FindCopyInsertPoint(MachineBasicBlock &MBB,
if (!SuccMBB.isLandingPad()) if (!SuccMBB.isLandingPad())
return MBB.getFirstTerminator(); return MBB.getFirstTerminator();
// Discover any definitions in this basic block. // Discover any defs/uses in this basic block.
SmallPtrSet<MachineInstr*, 8> DefUsesInMBB; SmallPtrSet<MachineInstr*, 8> DefUsesInMBB;
for (MachineRegisterInfo::def_iterator RI = MRI->def_begin(SrcReg), for (MachineRegisterInfo::reg_iterator RI = MRI->reg_begin(SrcReg),
RE = MRI->def_end(); RI != RE; ++RI) { RE = MRI->reg_end(); RI != RE; ++RI) {
MachineInstr *DefUseMI = &*RI; MachineInstr *DefUseMI = &*RI;
if (DefUseMI->getParent() == &MBB) if (DefUseMI->getParent() == &MBB)
DefUsesInMBB.insert(DefUseMI); DefUsesInMBB.insert(DefUseMI);
@ -155,11 +155,11 @@ llvm::PHIElimination::FindCopyInsertPoint(MachineBasicBlock &MBB,
// No defs. Insert the copy at the start of the basic block. // No defs. Insert the copy at the start of the basic block.
InsertPoint = MBB.begin(); InsertPoint = MBB.begin();
} else if (DefUsesInMBB.size() == 1) { } else if (DefUsesInMBB.size() == 1) {
// Insert the copy immediately after the def. // Insert the copy immediately after the def/use.
InsertPoint = *DefUsesInMBB.begin(); InsertPoint = *DefUsesInMBB.begin();
++InsertPoint; ++InsertPoint;
} else { } else {
// Insert the copy immediately after the last def. // Insert the copy immediately after the last def/use.
InsertPoint = MBB.end(); InsertPoint = MBB.end();
while (!DefUsesInMBB.count(&*--InsertPoint)) {} while (!DefUsesInMBB.count(&*--InsertPoint)) {}
++InsertPoint; ++InsertPoint;