From 79f0332c203b33c4afc0fb6ad946fbe041164e6e Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Fri, 6 Nov 2009 23:19:58 +0000 Subject: [PATCH] Fix a bug where we'd call SplitBlockPredecessors with a pred in the set only once even if it has multiple edges to BB. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86299 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/JumpThreading.cpp | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp index 62f7d51ff8c..4bbde1397c8 100644 --- a/lib/Transforms/Scalar/JumpThreading.cpp +++ b/lib/Transforms/Scalar/JumpThreading.cpp @@ -940,8 +940,17 @@ bool JumpThreading::ProcessThreadableEdges(Instruction *CondInst, // predecessors that will jump to it into a single predecessor. SmallVector PredsToFactor; for (unsigned i = 0, e = PredToDestList.size(); i != e; ++i) - if (PredToDestList[i].second == MostPopularDest) - PredsToFactor.push_back(PredToDestList[i].first); + if (PredToDestList[i].second == MostPopularDest) { + BasicBlock *Pred = PredToDestList[i].first; + + // This predecessor may be a switch or something else that has multiple + // edges to the block. Factor each of these edges by listing them + // according to # occurrences in PredsToFactor. + TerminatorInst *PredTI = Pred->getTerminator(); + for (unsigned i = 0, e = PredTI->getNumSuccessors(); i != e; ++i) + if (PredTI->getSuccessor(i) == BB) + PredsToFactor.push_back(Pred); + } BasicBlock *PredToThread; if (PredsToFactor.size() == 1)