diff options
| -rw-r--r-- | lib/Analysis/TypeBasedAliasAnalysis.cpp | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/lib/Analysis/TypeBasedAliasAnalysis.cpp b/lib/Analysis/TypeBasedAliasAnalysis.cpp index 044a93f866..16ff64e4cf 100644 --- a/lib/Analysis/TypeBasedAliasAnalysis.cpp +++ b/lib/Analysis/TypeBasedAliasAnalysis.cpp @@ -139,6 +139,8 @@ namespace { virtual void getAnalysisUsage(AnalysisUsage &AU) const; virtual AliasResult alias(const Location &LocA, const Location &LocB); virtual bool pointsToConstantMemory(const Location &Loc, bool OrLocal); + virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS); + virtual ModRefBehavior getModRefBehavior(const Function *F); virtual ModRefResult getModRefInfo(ImmutableCallSite CS, const Location &Loc); virtual ModRefResult getModRefInfo(ImmutableCallSite CS1, @@ -241,6 +243,27 @@ bool TypeBasedAliasAnalysis::pointsToConstantMemory(const Location &Loc, return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal); } +AliasAnalysis::ModRefBehavior +TypeBasedAliasAnalysis::getModRefBehavior(ImmutableCallSite CS) { + if (!EnableTBAA) + return AliasAnalysis::getModRefBehavior(CS); + + ModRefBehavior Min = UnknownModRefBehavior; + + // If this is an "immutable" type, we can assume the call doesn't write + // to memory. + if (const MDNode *M = CS.getInstruction()->getMetadata(LLVMContext::MD_tbaa)) + if (TBAANode(M).TypeIsImmutable()) + Min = OnlyReadsMemory; + + return std::min(AliasAnalysis::getModRefBehavior(CS), Min); +} + +AliasAnalysis::ModRefBehavior +TypeBasedAliasAnalysis::getModRefBehavior(const Function *F) { + return AliasAnalysis::getModRefBehavior(F); +} + AliasAnalysis::ModRefResult TypeBasedAliasAnalysis::getModRefInfo(ImmutableCallSite CS, const Location &Loc) { |