diff options
Diffstat (limited to 'llvm/lib/Analysis/BasicAliasAnalysis.cpp')
| -rw-r--r-- | llvm/lib/Analysis/BasicAliasAnalysis.cpp | 35 |
1 files changed, 32 insertions, 3 deletions
diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp index 03774b7..1ea1d41 100644 --- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp +++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp @@ -68,6 +68,9 @@ using namespace llvm; static cl::opt<bool> EnableRecPhiAnalysis("basic-aa-recphi", cl::Hidden, cl::init(true)); +static cl::opt<bool> EnableSeparateStorageAnalysis("basic-aa-separate-storage", + cl::Hidden, cl::init(false)); + /// SearchLimitReached / SearchTimes shows how often the limit of /// to decompose GEPs is reached. It will affect the precision /// of basic alias analysis. @@ -824,10 +827,10 @@ static bool notDifferentParent(const Value *O1, const Value *O2) { AliasResult BasicAAResult::alias(const MemoryLocation &LocA, const MemoryLocation &LocB, AAQueryInfo &AAQI, - const Instruction *) { + const Instruction *CtxI) { assert(notDifferentParent(LocA.Ptr, LocB.Ptr) && "BasicAliasAnalysis doesn't support interprocedural queries."); - return aliasCheck(LocA.Ptr, LocA.Size, LocB.Ptr, LocB.Size, AAQI); + return aliasCheck(LocA.Ptr, LocA.Size, LocB.Ptr, LocB.Size, AAQI, CtxI); } /// Checks to see if the specified callsite can clobber the specified memory @@ -1415,7 +1418,8 @@ AliasResult BasicAAResult::aliasPHI(const PHINode *PN, LocationSize PNSize, /// array references. AliasResult BasicAAResult::aliasCheck(const Value *V1, LocationSize V1Size, const Value *V2, LocationSize V2Size, - AAQueryInfo &AAQI) { + AAQueryInfo &AAQI, + const Instruction *CtxI) { // If either of the memory references is empty, it doesn't matter what the // pointer values are. if (V1Size.isZero() || V2Size.isZero()) @@ -1499,6 +1503,31 @@ AliasResult BasicAAResult::aliasCheck(const Value *V1, LocationSize V1Size, TLI, NullIsValidLocation))) return AliasResult::NoAlias; + if (CtxI && EnableSeparateStorageAnalysis) { + for (auto &AssumeVH : AC.assumptions()) { + if (!AssumeVH) + continue; + + AssumeInst *Assume = cast<AssumeInst>(AssumeVH); + + for (unsigned Idx = 0; Idx < Assume->getNumOperandBundles(); Idx++) { + OperandBundleUse OBU = Assume->getOperandBundleAt(Idx); + if (OBU.getTagName() == "separate_storage") { + assert(OBU.Inputs.size() == 2); + const Value *Hint1 = OBU.Inputs[0].get(); + const Value *Hint2 = OBU.Inputs[1].get(); + const Value *HintO1 = getUnderlyingObject(Hint1); + const Value *HintO2 = getUnderlyingObject(Hint2); + + if (((O1 == HintO1 && O2 == HintO2) || + (O1 == HintO2 && O2 == HintO1)) && + isValidAssumeForContext(Assume, CtxI, DT)) + return AliasResult::NoAlias; + } + } + } + } + // If one the accesses may be before the accessed pointer, canonicalize this // by using unknown after-pointer sizes for both accesses. This is // equivalent, because regardless of which pointer is lower, one of them |