Differential D58114 Diff 186459 llvm/trunk/lib/CodeGen/OptimizePHIs.cpp

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unsigned SingleValReg = 0;		unsigned SingleValReg = 0;
InstrSet PHIsInCycle;		InstrSet PHIsInCycle;
if (IsSingleValuePHICycle(MI, SingleValReg, PHIsInCycle) &&		if (IsSingleValuePHICycle(MI, SingleValReg, PHIsInCycle) &&
SingleValReg != 0) {		SingleValReg != 0) {
unsigned OldReg = MI->getOperand(0).getReg();		unsigned OldReg = MI->getOperand(0).getReg();
if (!MRI->constrainRegClass(SingleValReg, MRI->getRegClass(OldReg)))		if (!MRI->constrainRegClass(SingleValReg, MRI->getRegClass(OldReg)))
continue;		continue;

// for the case SingleValReg taken from copy instr
MRI->clearKillFlags(SingleValReg);

MRI->replaceRegWith(OldReg, SingleValReg);		MRI->replaceRegWith(OldReg, SingleValReg);
MI->eraseFromParent();		MI->eraseFromParent();

		// The kill flags on OldReg and SingleValReg may no longer be correct.
		MRI->clearKillFlags(SingleValReg);

++NumPHICycles;		++NumPHICycles;
Changed = true;		Changed = true;
continue;		continue;
}		}

// Check for dead PHI cycles.		// Check for dead PHI cycles.
PHIsInCycle.clear();		PHIsInCycle.clear();
if (IsDeadPHICycle(MI, PHIsInCycle)) {		if (IsDeadPHICycle(MI, PHIsInCycle)) {
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