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-rw-r--r--lib/CodeGen/PHIElimination.cpp20
1 files changed, 2 insertions, 18 deletions
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index 53ab8b03ee..2e30cc6abd 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -353,7 +353,7 @@ bool llvm::PHIElimination::SplitPHIEdges(MachineFunction &MF,
// We break edges when registers are live out from the predecessor block
// (not considering PHI nodes). If the register is live in to this block
// anyway, we would gain nothing from splitting.
- if (isLiveOut(Reg, *PreMBB, LV) && !isLiveIn(Reg, MBB, LV))
+ if (!LV.isLiveIn(Reg, MBB) && isLiveOut(Reg, *PreMBB, LV))
SplitCriticalEdge(PreMBB, &MBB);
}
}
@@ -406,22 +406,6 @@ bool llvm::PHIElimination::isLiveOut(unsigned Reg, const MachineBasicBlock &MBB,
return false;
}
-bool llvm::PHIElimination::isLiveIn(unsigned Reg, const MachineBasicBlock &MBB,
- LiveVariables &LV) {
- LiveVariables::VarInfo &VI = LV.getVarInfo(Reg);
-
- if (VI.AliveBlocks.test(MBB.getNumber()))
- return true;
-
- // defined in MBB?
- const MachineInstr *Def = MRI->getVRegDef(Reg);
- if (Def && Def->getParent() == &MBB)
- return false;
-
- // killed in MBB?
- return VI.findKill(&MBB);
-}
-
MachineBasicBlock *PHIElimination::SplitCriticalEdge(MachineBasicBlock *A,
MachineBasicBlock *B) {
assert(A && B && "Missing MBB end point");
@@ -463,7 +447,7 @@ MachineBasicBlock *PHIElimination::SplitCriticalEdge(MachineBasicBlock *A,
i->getOperand(ni+1).setMBB(NMBB);
if (LiveVariables *LV=getAnalysisIfAvailable<LiveVariables>())
- LV->addNewBlock(NMBB, A);
+ LV->addNewBlock(NMBB, A, B);
if (MachineDominatorTree *MDT=getAnalysisIfAvailable<MachineDominatorTree>())
MDT->addNewBlock(NMBB, A);