diff options
Diffstat (limited to 'lib/Transforms/Utils/LCSSA.cpp')
| -rw-r--r-- | lib/Transforms/Utils/LCSSA.cpp | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/lib/Transforms/Utils/LCSSA.cpp b/lib/Transforms/Utils/LCSSA.cpp index b2e5fa6..b654111 100644 --- a/lib/Transforms/Utils/LCSSA.cpp +++ b/lib/Transforms/Utils/LCSSA.cpp @@ -207,6 +207,8 @@ bool LCSSA::ProcessInstruction(Instruction *Inst, DomTreeNode *DomNode = DT->getNode(DomBB); + SmallVector<PHINode*, 16> AddedPHIs; + SSAUpdater SSAUpdate; SSAUpdate.Initialize(Inst->getType(), Inst->getName()); @@ -220,9 +222,10 @@ bool LCSSA::ProcessInstruction(Instruction *Inst, // If we already inserted something for this BB, don't reprocess it. if (SSAUpdate.HasValueForBlock(ExitBB)) continue; - PHINode *PN = PHINode::Create(Inst->getType(), Inst->getName()+".lcssa", + PHINode *PN = PHINode::Create(Inst->getType(), + PredCache.GetNumPreds(ExitBB), + Inst->getName()+".lcssa", ExitBB->begin()); - PN->reserveOperandSpace(PredCache.GetNumPreds(ExitBB)); // Add inputs from inside the loop for this PHI. for (BasicBlock **PI = PredCache.GetPreds(ExitBB); *PI; ++PI) { @@ -236,6 +239,8 @@ bool LCSSA::ProcessInstruction(Instruction *Inst, &PN->getOperandUse( PN->getOperandNumForIncomingValue(PN->getNumIncomingValues()-1))); } + + AddedPHIs.push_back(PN); // Remember that this phi makes the value alive in this block. SSAUpdate.AddAvailableValue(ExitBB, PN); @@ -262,6 +267,12 @@ bool LCSSA::ProcessInstruction(Instruction *Inst, // Otherwise, do full PHI insertion. SSAUpdate.RewriteUse(*UsesToRewrite[i]); } + + // Remove PHI nodes that did not have any uses rewritten. + for (unsigned i = 0, e = AddedPHIs.size(); i != e; ++i) { + if (AddedPHIs[i]->use_empty()) + AddedPHIs[i]->eraseFromParent(); + } return true; } |
