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Undo PHI elimination copy placement patch. This causes coalescing (performace) issues.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49198 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2008-04-04 01:20:05 +00:00
parent e04f736545
commit fc5423d561
1 changed files with 1 additions and 30 deletions
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31
lib/CodeGen/PHIElimination.cpp
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@ -49,12 +49,6 @@ namespace {
} }
private: private:
/// findInsertionPoint - Find a safe location to insert a move to copy
/// source of a PHI instruction.
MachineBasicBlock::iterator
findInsertionPoint(MachineBasicBlock &MBB, MachineInstr *DefMI,
unsigned DstReg, unsigned SrcReg) const;
/// EliminatePHINodes - Eliminate phi nodes by inserting copy instructions /// EliminatePHINodes - Eliminate phi nodes by inserting copy instructions
/// in predecessor basic blocks. /// in predecessor basic blocks.
/// ///
@ -132,28 +126,6 @@ bool PNE::EliminatePHINodes(MachineFunction &MF, MachineBasicBlock &MBB) {
return true; return true;
} }
/// findInsertionPoint - Find a safe location to insert a move to copy
/// source of a PHI instruction.
MachineBasicBlock::iterator
PNE::findInsertionPoint(MachineBasicBlock &MBB, MachineInstr *DefMI,
unsigned DstReg, unsigned SrcReg) const {
if (DefMI->getOpcode() == TargetInstrInfo::PHI ||
DefMI->getParent() != &MBB)
return MBB.getFirstTerminator();
for (MachineRegisterInfo::use_iterator I = MRI->use_begin(SrcReg),
E = MRI->use_end(); I != E; ++I)
if (I->getParent() == &MBB)
return MBB.getFirstTerminator();
for (MachineRegisterInfo::use_iterator I = MRI->use_begin(DstReg),
E = MRI->use_end(); I != E; ++I)
if (I->getParent() == &MBB)
return MBB.getFirstTerminator();
MachineBasicBlock::iterator I = DefMI;
return ++I;
}
/// LowerAtomicPHINode - Lower the PHI node at the top of the specified block, /// LowerAtomicPHINode - Lower the PHI node at the top of the specified block,
/// under the assuption that it needs to be lowered in a way that supports /// under the assuption that it needs to be lowered in a way that supports
/// atomic execution of PHIs. This lowering method is always correct all of the /// atomic execution of PHIs. This lowering method is always correct all of the
@ -242,8 +214,7 @@ void PNE::LowerAtomicPHINode(MachineBasicBlock &MBB,
// Find a safe location to insert the copy, this may be the first // Find a safe location to insert the copy, this may be the first
// terminator in the block (or end()). // terminator in the block (or end()).
MachineBasicBlock::iterator InsertPos = MachineBasicBlock::iterator InsertPos = opBlock.getFirstTerminator();
findInsertionPoint(opBlock, DefMI, IncomingReg, SrcReg);
// Insert the copy. // Insert the copy.
TII->copyRegToReg(opBlock, InsertPos, IncomingReg, SrcReg, RC, RC); TII->copyRegToReg(opBlock, InsertPos, IncomingReg, SrcReg, RC, RC);