From b3bc8fa75508ae996dbc71283186502f2c43f47c Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 14 May 2002 15:24:07 +0000 Subject: [PATCH] Fix bug: test/Regression/Transforms/InstCombine/2002-05-14-TouchDeletedInst.ll "This testcase caused instcombine to fail because it got the same instruction on it's worklist more than once (which is ok), but then deleted the instruction. Since the inst stayed on the worklist, as soon as it came back up to be processed, bad things happened, and opt asserted." git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2623 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/InstructionCombining.cpp | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 0f676426e1b..0812fca6e97 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -26,6 +26,7 @@ #include "llvm/Support/InstIterator.h" #include "llvm/Support/InstVisitor.h" #include "Support/StatisticReporter.h" +#include static Statistic<> NumCombined("instcombine\t- Number of insts combined"); @@ -551,8 +552,18 @@ bool InstCombiner::runOnFunction(Function *F) { if (Result) { ++NumCombined; // Should we replace the old instruction with a new one? - if (Result != I) + if (Result != I) { + // Instructions can end up on the worklist more than once. Make sure + // we do not process an instruction that has been deleted. + std::vector::iterator It = std::find(WorkList.begin(), + WorkList.end(), I); + while (It != WorkList.end()) { + It = WorkList.erase(It); + It = std::find(It, WorkList.end(), I); + } + ReplaceInstWithInst(I, Result); + } WorkList.push_back(Result); AddUsesToWorkList(Result);