From 838b97edfaf7470941d0e89ef3b9ed8867c93fc4 Mon Sep 17 00:00:00 2001 From: Cameron Zwarich Date: Tue, 15 Mar 2011 07:41:25 +0000 Subject: Do not add PHIs with no users when creating LCSSA form. Patch by Andrew Clinton. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127674 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/LCSSA.cpp | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'lib/Transforms') diff --git a/lib/Transforms/Utils/LCSSA.cpp b/lib/Transforms/Utils/LCSSA.cpp index b2e5fa6d7e..ade4a43c6c 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 AddedPHIs; + SSAUpdater SSAUpdate; SSAUpdate.Initialize(Inst->getType(), Inst->getName()); @@ -236,6 +238,8 @@ 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 +266,12 @@ 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]->hasNUsesOrMore(1)) + AddedPHIs[i]->eraseFromParent(); + } return true; } -- cgit v1.2.3-18-g5258