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| author | Joseph Tremoulet <jotrem@microsoft.com> | 2018-06-15 16:52:40 +0000 |
|---|---|---|
| committer | Joseph Tremoulet <jotrem@microsoft.com> | 2018-06-15 16:52:40 +0000 |
| commit | 6f406d4f022e059033b335bc024d0c652d6d8c52 (patch) | |
| tree | 0d7be596ce250ed81d9b04ccd6ed9ec615f7eaed /llvm/lib/Transforms | |
| parent | 4adf24502ec8c993e3da2fe0ad2f4921e5a76bb9 (diff) | |
| download | bcm5719-llvm-6f406d4f022e059033b335bc024d0c652d6d8c52.tar.gz bcm5719-llvm-6f406d4f022e059033b335bc024d0c652d6d8c52.zip | |
[InstCombine] Avoid iteration/mutation conflict
Summary:
When iterating users of a multiply in processUMulZExtIdiom, the
call to setOperand in the truncation case may replace the use
being visited; make sure the iterator has been advanced before
doing that replacement.
Reviewers: majnemer, davide
Reviewed By: davide
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48192
llvm-svn: 334844
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 8d6beba6feb..d52ea2cf6eb 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -3849,7 +3849,8 @@ static Instruction *processUMulZExtIdiom(ICmpInst &I, Value *MulVal, // mul.with.overflow and adjust properly mask/size. if (MulVal->hasNUsesOrMore(2)) { Value *Mul = Builder.CreateExtractValue(Call, 0, "umul.value"); - for (User *U : MulVal->users()) { + for (auto UI = MulVal->user_begin(), UE = MulVal->user_end(); UI != UE;) { + User *U = *UI++; if (U == &I || U == OtherVal) continue; if (TruncInst *TI = dyn_cast<TruncInst>(U)) { |
