diff options
Diffstat (limited to 'lib/Analysis/BasicAliasAnalysis.cpp')
| -rw-r--r-- | lib/Analysis/BasicAliasAnalysis.cpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp index 6bb84d4e45..11cba991a9 100644 --- a/lib/Analysis/BasicAliasAnalysis.cpp +++ b/lib/Analysis/BasicAliasAnalysis.cpp @@ -425,8 +425,13 @@ BasicAliasAnalysis::getModRefInfo(ImmutableCallSite CS1, ModRefBehavior CS2B = AliasAnalysis::getModRefBehavior(CS2); if (CS2B == DoesNotAccessMemory) return NoModRef; - // If they both only read from memory, just return ref. + // If they both only read from memory, there is no dependence. if (CS1B == OnlyReadsMemory && CS2B == OnlyReadsMemory) + return NoModRef; + + // If CS1 only reads memory, the only dependence on CS2 can be + // from CS1 reading memory written by CS2. + if (CS1B == OnlyReadsMemory) return Ref; // Otherwise, fall back to NoAA (mod+ref). |