From 0b37f14371d601bab6493f47aa9326abb3e768e2 Mon Sep 17 00:00:00 2001 From: Nadav Rotem Date: Sun, 30 Dec 2012 07:47:00 +0000 Subject: LoopVectorizer: Fix a bug in the code that updates the loop exiting block. LCSSA PHIs may have undef values. The vectorizer updates values that are used by outside users such as PHIs. The bug happened because undefs are not loop values. This patch handles these PHIs. PR14725 llvm-svn: 171251 --- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'llvm/lib/Transforms/Vectorize/LoopVectorize.cpp') diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp index 7fb9bbada0f..653c111182c 100644 --- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -909,6 +909,19 @@ InnerLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) { (RdxPhi)->setIncomingValue(SelfEdgeBlockIdx, Scalar0); (RdxPhi)->setIncomingValue(IncomingEdgeBlockIdx, RdxDesc.LoopExitInstr); }// end of for each redux variable. + + // The Loop exit block may have single value PHI nodes where the incoming + // value is 'undef'. While vectorizing we only handled real values that + // were defined inside the loop. Here we handle the 'undef case'. + // See PR14725. + for (BasicBlock::iterator LEI = LoopExitBlock->begin(), + LEE = LoopExitBlock->end(); LEI != LEE; ++LEI) { + PHINode *LCSSAPhi = dyn_cast(LEI); + if (!LCSSAPhi) continue; + if (LCSSAPhi->getNumIncomingValues() == 1) + LCSSAPhi->addIncoming(UndefValue::get(LCSSAPhi->getType()), + LoopMiddleBlock); + } } Value *InnerLoopVectorizer::createEdgeMask(BasicBlock *Src, BasicBlock *Dst) { -- cgit v1.2.3