From f7711010e12503f0bd6e8c7a15c648fcd02d358b Mon Sep 17 00:00:00 2001 From: Andrew Trick Date: Tue, 20 Mar 2012 21:24:52 +0000 Subject: LoopSimplify bug fix. Handle indirect loop back edges. Do not call SplitBlockPredecessors on a loop preheader when one of the predecessors is an indirectbr. Otherwise, you will hit this assert: !isa(Preds[i]->getTerminator()) && "Cannot split an edge from an IndirectBrInst" llvm-svn: 153134 --- llvm/lib/Transforms/Utils/LoopSimplify.cpp | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'llvm/lib/Transforms/Utils/LoopSimplify.cpp') diff --git a/llvm/lib/Transforms/Utils/LoopSimplify.cpp b/llvm/lib/Transforms/Utils/LoopSimplify.cpp index 1b6a19d..0bc185d 100644 --- a/llvm/lib/Transforms/Utils/LoopSimplify.cpp +++ b/llvm/lib/Transforms/Utils/LoopSimplify.cpp @@ -538,8 +538,7 @@ void LoopSimplify::PlaceSplitBlockCarefully(BasicBlock *NewBB, /// Loop *LoopSimplify::SeparateNestedLoop(Loop *L, LPPassManager &LPM, BasicBlock *Preheader) { - // Don't try to separate loops without a preheader (this excludes - // loop headers which are targeted by an indirectbr). + // Don't try to separate loops without a preheader. if (!Preheader) return 0; @@ -554,11 +553,15 @@ Loop *LoopSimplify::SeparateNestedLoop(Loop *L, LPPassManager &LPM, // handles the case when a PHI node has multiple instances of itself as // arguments. SmallVector OuterLoopPreds; - for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) + for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { if (PN->getIncomingValue(i) != PN || - !L->contains(PN->getIncomingBlock(i))) + !L->contains(PN->getIncomingBlock(i))) { + // We can't split indirectbr edges. + if (isa(PN->getIncomingBlock(i)->getTerminator())) + return 0; OuterLoopPreds.push_back(PN->getIncomingBlock(i)); - + } + } DEBUG(dbgs() << "LoopSimplify: Splitting out a new outer loop\n"); // If ScalarEvolution is around and knows anything about values in -- cgit v1.1