From 84b6706d9003f6078a81ed7d84f4e49ee70f7ef8 Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Tue, 20 Sep 2011 22:23:09 +0000 Subject: [PATCH] Omit extracting a loop if one of the exits is a landing pad. The landing pad must accompany the invoke when it's extracted. However, if it does, then the loop isn't properly extracted. I.e., the resulting extraction has a loop in it. The extracted function is then extracted, etc. resulting in an infinite loop. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140193 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/IPO/LoopExtractor.cpp | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/lib/Transforms/IPO/LoopExtractor.cpp b/lib/Transforms/IPO/LoopExtractor.cpp index 714282b2b5e..826ade38d1e 100644 --- a/lib/Transforms/IPO/LoopExtractor.cpp +++ b/lib/Transforms/IPO/LoopExtractor.cpp @@ -101,18 +101,24 @@ bool LoopExtractor::runOnLoop(Loop *L, LPPassManager &LPM) { L->getHeader()->getParent()->getEntryBlock().getTerminator(); if (!isa(EntryTI) || !cast(EntryTI)->isUnconditional() || - EntryTI->getSuccessor(0) != L->getHeader()) + EntryTI->getSuccessor(0) != L->getHeader()) { ShouldExtractLoop = true; - else { + } else { // Check to see if any exits from the loop are more than just return - // blocks. + // blocks. We also must omit landing pads. Landing pads must accompany the + // invoke instruction. But this would result in a loop in the extracted + // function. An infinite cycle occurs when it tries to extract that loop as + // well. SmallVector ExitBlocks; L->getExitBlocks(ExitBlocks); - for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i) - if (!isa(ExitBlocks[i]->getTerminator())) { + for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i) { + if (!isa(ExitBlocks[i]->getTerminator())) ShouldExtractLoop = true; + if (ExitBlocks[i]->isLandingPad()) { + ShouldExtractLoop = false; break; } + } } if (ShouldExtractLoop) { if (NumLoops == 0) return Changed; -- 2.34.1