diff options
Diffstat (limited to 'lib/Analysis/BasicAliasAnalysis.cpp')
-rw-r--r-- | lib/Analysis/BasicAliasAnalysis.cpp | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp index f1a9dd991c..d0e186c5f2 100644 --- a/lib/Analysis/BasicAliasAnalysis.cpp +++ b/lib/Analysis/BasicAliasAnalysis.cpp @@ -1009,7 +1009,15 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size, return NoAlias; } } else { - if (V1Size != UnknownSize) { + // We have the situation where: + // + + + // | BaseOffset | + // ---------------->| + // |-->V1Size |-------> V2Size + // GEP1 V2 + // We need to know that V2Size is not unknown, otherwise we might have + // stripped a gep with negative index ('gep <ptr>, -1, ...). + if (V1Size != UnknownSize && V2Size != UnknownSize) { if (-(uint64_t)GEP1BaseOffset < V1Size) return PartialAlias; return NoAlias; |