From 299520de7c5358a30dd7786cf9fe9f9a6ce37d94 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 18 Feb 2006 00:33:17 +0000 Subject: [PATCH] Fix Transforms/SimplifyCFG/2006-02-17-InfiniteUnroll.ll git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26275 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/SimplifyCFG.cpp | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 1159cd36f5e..3c6c02f7e99 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1426,8 +1426,8 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { PBI->setSuccessor(1, OldTrue); } - if (PBI->getSuccessor(0) == TrueDest || - PBI->getSuccessor(1) == FalseDest) { + if ((PBI->getSuccessor(0) == TrueDest && FalseDest != BB) || + (PBI->getSuccessor(1) == FalseDest && TrueDest != BB)) { // Clone Cond into the predecessor basic block, and or/and the // two conditions together. Instruction *New = Cond->clone(); @@ -1512,6 +1512,12 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { PBIOp = BIOp = -1; } + // Check to make sure that the other destination of this branch + // isn't BB itself. If so, this is an infinite loop that will + // keep getting unwound. + if (PBIOp != -1 && PBI->getSuccessor(PBIOp) == BB) + PBIOp = BIOp = -1; + // Finally, if everything is ok, fold the branches to logical ops. if (PBIOp != -1) { BasicBlock *CommonDest = PBI->getSuccessor(PBIOp); -- 2.34.1