[NFC][AA] Prepare to convert AliasResult to class with PartialAlias offset.

[dfukalov]

Summary

Main reason is preparation to transform AliasResult to class that contains
offset for PartialAlias case.

[dfukalov]

llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.cpp

43–44

@rampitec, @arsenm, would you please take a look to this 'typography'? I moved out table comments since the table width increased significantly with AliasResult::s

[nikic]

This looks fine to me, though I'm not clear on how making it an enum class will help with moving to a class. Do you happen to have the patch for that already?

llvm/include/llvm/Analysis/AliasAnalysis.h

77

This paragraph should be dropped.

llvm/lib/Target/Hexagon/HexagonStoreWidening.cpp

183

Could also write this as AA->isNoAlias(L, SL) (same in some following occurrences). No strong preference though.

[dfukalov]

No, I don't have a patch at the moment, but will upload one since you're generally ok with this step.

I thought to convert the enum to a something like

class AliasResult {
public:
  int16_t Offset : 14;
  uint8_t EnumStorage : 2;
  ...
public:
  enum {...};
  ...
}

So after that access to the enum values needs AliasResult:: and I decided to split this NFC part away.
And using scoped enum allowed to find all uses.

[rampitec]

llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.cpp

43–44

Does it work with "using AliasResult;"?

[dfukalov]

llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.cpp

43–44

No, using AliasResult::NoAlias; in a block will be available since C++20.

At the moment I can place using AR = AliasResult; and then use AR:: but it will increase current table width of 120 to 138.

[rampitec]

llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.cpp

43–44

Then I can only think about defines before the block and undefs after.

[dfukalov]

Made the enum unscoped back since it going to be unscoped within a class planned
to be new AliasResult.

[dfukalov]

Converted all AliasAnalysis::alias() == AliasResult::NoAlias to
AliasAnalysis::isNoAlias().

[dfukalov]

llvm/include/llvm/Analysis/AliasAnalysis.h

77

I declined to make the enum scoped since it's going to be unscoped in a planned AliasResult class.

llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.cpp

50–65

@rampitec, I moved the table into the function additionally.
Could you please check defines naming?

[rampitec]

llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.cpp

50–65

Thanks, I am OK with this.

[asbirlea]

This change looks fine. Could you update the follow-up as well as a dependent patch?

llvm/include/llvm/Analysis/AliasAnalysis.h

 ///
 /// These results are always computed between two MemoryLocation objects as
 /// a query to some alias analysis.
 ///
 /// Note that these are unscoped enumerations because we would like to support
 /// implicitly testing a result for the existence of any possible aliasing with
 /// a conversion to bool, but an "enum class" doesn't support this. The
 /// canonical names from the literature are suffixed and unique anyways, and so
 /// they serve as global constants in LLVM for these results.
 ///
 /// See docs/AliasAnalysis.html for more information on the specific meanings
 /// of these values.
 enum AliasResult : uint8_t {
   /// The two locations do not alias at all.
   ///
   /// This value is arranged to convert to false, while all other values
   /// convert to true. This allows a boolean context to convert the result to
public:
   AliasResult alias(const Value *V1, const Value *V2) {
     return alias(MemoryLocation::getBeforeOrAfter(V1),
                  MemoryLocation::getBeforeOrAfter(V2));
   }
 
   /// A trivial helper function to check to see if the specified pointers are
   /// no-alias.
   bool isNoAlias(const MemoryLocation &LocA, const MemoryLocation &LocB) {
-    return alias(LocA, LocB) == NoAlias;
+    return alias(LocA, LocB) == AliasResult::NoAlias;
   }
 
   /// A convenience wrapper around the \c isNoAlias helper interface.
   bool isNoAlias(const Value *V1, LocationSize V1Size, const Value *V2,
                  LocationSize V2Size) {
     return isNoAlias(MemoryLocation(V1, V1Size), MemoryLocation(V2, V2Size));
   }
 
   /// A convenience wrapper around the \c isNoAlias helper interface.
   bool isNoAlias(const Value *V1, const Value *V2) {
     return isNoAlias(MemoryLocation::getBeforeOrAfter(V1),
                      MemoryLocation::getBeforeOrAfter(V2));
   }
 
   /// A trivial helper function to check to see if the specified pointers are
   /// must-alias.
   bool isMustAlias(const MemoryLocation &LocA, const MemoryLocation &LocB) {
-    return alias(LocA, LocB) == MustAlias;
+    return alias(LocA, LocB) == AliasResult::MustAlias;
   }
 
   /// A convenience wrapper around the \c isMustAlias helper interface.
   bool isMustAlias(const Value *V1, const Value *V2) {
     return alias(V1, LocationSize::precise(1), V2, LocationSize::precise(1)) ==
-           MustAlias;
+           AliasResult::MustAlias;
   }
 
   /// Checks whether the given location points to constant memory, or if
   /// \p OrLocal is true whether it points to a local alloca.
   bool pointsToConstantMemory(const MemoryLocation &Loc, bool OrLocal = false);
 
   /// A convenience wrapper around the primary \c pointsToConstantMemory
   /// interface.
public:
   }
   ModRefInfo getArgModRefInfo(const CallBase *Call, unsigned ArgIdx) {
     return AA.getArgModRefInfo(Call, ArgIdx);
   }
   FunctionModRefBehavior getModRefBehavior(const CallBase *Call) {
     return AA.getModRefBehavior(Call);
   }
   bool isMustAlias(const MemoryLocation &LocA, const MemoryLocation &LocB) {
-    return alias(LocA, LocB) == MustAlias;
+    return alias(LocA, LocB) == AliasResult::MustAlias;
   }
   bool isMustAlias(const Value *V1, const Value *V2) {
     return alias(MemoryLocation(V1, LocationSize::precise(1)),
-                 MemoryLocation(V2, LocationSize::precise(1))) == MustAlias;
+                 MemoryLocation(V2, LocationSize::precise(1))) ==
+           AliasResult::MustAlias;
   }
   Optional<int64_t> getClobberOffset(const MemoryLocation &LocA,
                                      const MemoryLocation &LocB) const;
 };
 
 /// Temporary typedef for legacy code that uses a generic \c AliasAnalysis
 /// pointer or reference.
 using AliasAnalysis = AAResults;
protected:
   /// performance problems when they use this routine, in the case of a large
   /// number of alias analyses being aggregated, it can be expensive to walk
   /// back across the chain.
   AAResultsProxy getBestAAResults() { return AAResultsProxy(AAR, derived()); }
 
 public:
   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB,
                     AAQueryInfo &AAQI) {
-    return MayAlias;
+    return AliasResult::MayAlias;
   }
 
   bool pointsToConstantMemory(const MemoryLocation &Loc, AAQueryInfo &AAQI,
                               bool OrLocal) {
     return false;
   }
 
   ModRefInfo getArgModRefInfo(const CallBase *Call, unsigned ArgIdx) {

llvm/include/llvm/Analysis/CFLSteensAliasAnalysis.h

public:
   /// Return nullptr if the summary is not found or not available
   const cflaa::AliasSummary *getAliasSummary(Function &Fn);
 
   AliasResult query(const MemoryLocation &LocA, const MemoryLocation &LocB);
 
   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB,
                     AAQueryInfo &AAQI) {
     if (LocA.Ptr == LocB.Ptr)
-      return MustAlias;
+      return AliasResult::MustAlias;
 
     // Comparisons between global variables and other constants should be
     // handled by BasicAA.
     // CFLSteensAA may report NoAlias when comparing a GlobalValue and
     // ConstantExpr, but every query needs to have at least one Value tied to a
     // Function, and neither GlobalValues nor ConstantExprs are.
     if (isa<Constant>(LocA.Ptr) && isa<Constant>(LocB.Ptr))
       return AAResultBase::alias(LocA, LocB, AAQI);
 
     AliasResult QueryResult = query(LocA, LocB);
-    if (QueryResult == MayAlias)
+    if (QueryResult == AliasResult::MayAlias)
       return AAResultBase::alias(LocA, LocB, AAQI);
 
     return QueryResult;
   }
 
 private:
   std::function<const TargetLibraryInfo &(Function &)> GetTLI;
 

llvm/include/llvm/Analysis/MemorySSA.h

 protected:
   friend class MemorySSA;
   friend class MemorySSAUpdater;
 
   MemoryUseOrDef(LLVMContext &C, MemoryAccess *DMA, unsigned Vty,
                  DeleteValueTy DeleteValue, Instruction *MI, BasicBlock *BB,
                  unsigned NumOperands)
       : MemoryAccess(C, Vty, DeleteValue, BB, NumOperands),
-        MemoryInstruction(MI), OptimizedAccessAlias(MayAlias) {
+        MemoryInstruction(MI), OptimizedAccessAlias(AliasResult::MayAlias) {
     setDefiningAccess(DMA);
   }
 
   // Use deleteValue() to delete a generic MemoryUseOrDef.
   ~MemoryUseOrDef() = default;
 
   void setOptimizedAccessType(Optional<AliasResult> AR) {
     OptimizedAccessAlias = AR;
   }
 
   void setDefiningAccess(MemoryAccess *DMA, bool Optimized = false,
-                         Optional<AliasResult> AR = MayAlias) {
+                         Optional<AliasResult> AR = AliasResult::MayAlias) {
     if (!Optimized) {
       setOperand(0, DMA);
       return;
     }
     setOptimized(DMA);
     setOptimizedAccessType(AR);
   }
 

llvm/lib/Analysis/AliasAnalysis.cpp

 AliasResult AAResults::alias(const MemoryLocation &LocA,
                              const MemoryLocation &LocB) {
   AAQueryInfo AAQIP;
   return alias(LocA, LocB, AAQIP);
 }
 
 AliasResult AAResults::alias(const MemoryLocation &LocA,
                              const MemoryLocation &LocB, AAQueryInfo &AAQI) {
-  AliasResult Result = MayAlias;
+  AliasResult Result = AliasResult::MayAlias;
 
   if (EnableAATrace) {
     for (unsigned I = 0; I < AAQI.Depth; ++I)
       dbgs() << "  ";
     dbgs() << "Start " << *LocA.Ptr << " @ " << LocA.Size << ", "
            << *LocB.Ptr << " @ " << LocB.Size << "\n";
   }
 
   AAQI.Depth++;
   for (const auto &AA : AAs) {
     Result = AA->alias(LocA, LocB, AAQI);
-    if (Result != MayAlias)
+    if (Result != AliasResult::MayAlias)
       break;
   }
   AAQI.Depth--;
 
   if (EnableAATrace) {
     for (unsigned I = 0; I < AAQI.Depth; ++I)
       dbgs() << "  ";
     dbgs() << "End " << *LocA.Ptr << " @ " << LocA.Size << ", "
            << *LocB.Ptr << " @ " << LocB.Size << " = " << Result << "\n";
   }
 
   if (AAQI.Depth == 0) {
-    if (Result == NoAlias)
+    if (Result == AliasResult::NoAlias)
       ++NumNoAlias;
-    else if (Result == MustAlias)
+    else if (Result == AliasResult::MustAlias)
       ++NumMustAlias;
     else
       ++NumMayAlias;
   }
   return Result;
 }
 
 bool AAResults::pointsToConstantMemory(const MemoryLocation &Loc,
if (doesAccessArgPointees(MRB)) {
       for (auto AI = Call->arg_begin(), AE = Call->arg_end(); AI != AE; ++AI) {
         const Value *Arg = *AI;
         if (!Arg->getType()->isPointerTy())
           continue;
         unsigned ArgIdx = std::distance(Call->arg_begin(), AI);
         MemoryLocation ArgLoc =
             MemoryLocation::getForArgument(Call, ArgIdx, TLI);
         AliasResult ArgAlias = alias(ArgLoc, Loc, AAQI);
-        if (ArgAlias != NoAlias) {
+        if (ArgAlias != AliasResult::NoAlias) {
           ModRefInfo ArgMask = getArgModRefInfo(Call, ArgIdx);
           AllArgsMask = unionModRef(AllArgsMask, ArgMask);
         }
         // Conservatively clear IsMustAlias unless only MustAlias is found.
-        IsMustAlias &= (ArgAlias == MustAlias);
+        IsMustAlias &= (ArgAlias == AliasResult::MustAlias);
       }
     }
     // Return NoModRef if no alias found with any argument.
     if (isNoModRef(AllArgsMask))
       return ModRefInfo::NoModRef;
     // Logical & between other AA analyses and argument analysis.
     Result = intersectModRef(Result, AllArgsMask);
     // If only MustAlias found above, set Must bit.
if (Result == FMRB_DoesNotAccessMemory)
       return Result;
   }
 
   return Result;
 }
 
 raw_ostream &llvm::operator<<(raw_ostream &OS, AliasResult AR) {
   switch (AR) {
-  case NoAlias:
+  case AliasResult::NoAlias:
     OS << "NoAlias";
     break;
-  case MustAlias:
+  case AliasResult::MustAlias:
     OS << "MustAlias";
     break;
-  case MayAlias:
+  case AliasResult::MayAlias:
     OS << "MayAlias";
     break;
-  case PartialAlias:
+  case AliasResult::PartialAlias:
     OS << "PartialAlias";
     break;
   }
   return OS;
 }
 
 //===----------------------------------------------------------------------===//
 // Helper method implementation
ModRefInfo AAResults::getModRefInfo(const LoadInst *L,
   // Be conservative in the face of atomic.
   if (isStrongerThan(L->getOrdering(), AtomicOrdering::Unordered))
     return ModRefInfo::ModRef;
 
   // If the load address doesn't alias the given address, it doesn't read
   // or write the specified memory.
   if (Loc.Ptr) {
     AliasResult AR = alias(MemoryLocation::get(L), Loc, AAQI);
-    if (AR == NoAlias)
+    if (AR == AliasResult::NoAlias)
       return ModRefInfo::NoModRef;
-    if (AR == MustAlias)
+    if (AR == AliasResult::MustAlias)
       return ModRefInfo::MustRef;
   }
   // Otherwise, a load just reads.
   return ModRefInfo::Ref;
 }
 
 ModRefInfo AAResults::getModRefInfo(const StoreInst *S,
                                     const MemoryLocation &Loc) {
   AAQueryInfo AAQIP;
   return getModRefInfo(S, Loc, AAQIP);
 }
 ModRefInfo AAResults::getModRefInfo(const StoreInst *S,
                                     const MemoryLocation &Loc,
                                     AAQueryInfo &AAQI) {
   // Be conservative in the face of atomic.
   if (isStrongerThan(S->getOrdering(), AtomicOrdering::Unordered))
     return ModRefInfo::ModRef;
 
   if (Loc.Ptr) {
     AliasResult AR = alias(MemoryLocation::get(S), Loc, AAQI);
     // If the store address cannot alias the pointer in question, then the
     // specified memory cannot be modified by the store.
-    if (AR == NoAlias)
+    if (AR == AliasResult::NoAlias)
       return ModRefInfo::NoModRef;
 
     // If the pointer is a pointer to constant memory, then it could not have
     // been modified by this store.
     if (pointsToConstantMemory(Loc, AAQI))
       return ModRefInfo::NoModRef;
 
     // If the store address aliases the pointer as must alias, set Must.
-    if (AR == MustAlias)
+    if (AR == AliasResult::MustAlias)
       return ModRefInfo::MustMod;
   }
 
   // Otherwise, a store just writes.
   return ModRefInfo::Mod;
 }
 
 ModRefInfo AAResults::getModRefInfo(const FenceInst *S, const MemoryLocation &Loc) {

 
 ModRefInfo AAResults::getModRefInfo(const VAArgInst *V,
                                     const MemoryLocation &Loc,
                                     AAQueryInfo &AAQI) {
   if (Loc.Ptr) {
     AliasResult AR = alias(MemoryLocation::get(V), Loc, AAQI);
     // If the va_arg address cannot alias the pointer in question, then the
     // specified memory cannot be accessed by the va_arg.
-    if (AR == NoAlias)
+    if (AR == AliasResult::NoAlias)
       return ModRefInfo::NoModRef;
 
     // If the pointer is a pointer to constant memory, then it could not have
     // been modified by this va_arg.
     if (pointsToConstantMemory(Loc, AAQI))
       return ModRefInfo::NoModRef;
 
     // If the va_arg aliases the pointer as must alias, set Must.
-    if (AR == MustAlias)
+    if (AR == AliasResult::MustAlias)
       return ModRefInfo::MustModRef;
   }
 
   // Otherwise, a va_arg reads and writes.
   return ModRefInfo::ModRef;
 }
 
 ModRefInfo AAResults::getModRefInfo(const CatchPadInst *CatchPad,
ModRefInfo AAResults::getModRefInfo(const AtomicCmpXchgInst *CX,
   // Acquire/Release cmpxchg has properties that matter for arbitrary addresses.
   if (isStrongerThanMonotonic(CX->getSuccessOrdering()))
     return ModRefInfo::ModRef;
 
   if (Loc.Ptr) {
     AliasResult AR = alias(MemoryLocation::get(CX), Loc, AAQI);
     // If the cmpxchg address does not alias the location, it does not access
     // it.
-    if (AR == NoAlias)
+    if (AR == AliasResult::NoAlias)
       return ModRefInfo::NoModRef;
 
     // If the cmpxchg address aliases the pointer as must alias, set Must.
-    if (AR == MustAlias)
+    if (AR == AliasResult::MustAlias)
       return ModRefInfo::MustModRef;
   }
 
   return ModRefInfo::ModRef;
 }
 
 ModRefInfo AAResults::getModRefInfo(const AtomicRMWInst *RMW,
                                     const MemoryLocation &Loc) {
   AAQueryInfo AAQIP;
   return getModRefInfo(RMW, Loc, AAQIP);
 }
 
 ModRefInfo AAResults::getModRefInfo(const AtomicRMWInst *RMW,
                                     const MemoryLocation &Loc,
                                     AAQueryInfo &AAQI) {
   // Acquire/Release atomicrmw has properties that matter for arbitrary addresses.
   if (isStrongerThanMonotonic(RMW->getOrdering()))
     return ModRefInfo::ModRef;
 
   if (Loc.Ptr) {
     AliasResult AR = alias(MemoryLocation::get(RMW), Loc, AAQI);
     // If the atomicrmw address does not alias the location, it does not access
     // it.
-    if (AR == NoAlias)
+    if (AR == AliasResult::NoAlias)
       return ModRefInfo::NoModRef;
 
     // If the atomicrmw address aliases the pointer as must alias, set Must.
-    if (AR == MustAlias)
+    if (AR == AliasResult::MustAlias)
       return ModRefInfo::MustModRef;
   }
 
   return ModRefInfo::ModRef;
 }
 
 ModRefInfo AAResults::getModRefInfo(const Instruction *I,
                                     const Optional<MemoryLocation> &OptLoc,
if (!(*CI)->getType()->isPointerTy() ||
          !Call->isByValArgument(ArgNo)))
       continue;
 
     AliasResult AR = alias(*CI, Object);
     // If this is a no-capture pointer argument, see if we can tell that it
     // is impossible to alias the pointer we're checking.  If not, we have to
     // assume that the call could touch the pointer, even though it doesn't
     // escape.
-    if (AR != MustAlias)
+    if (AR != AliasResult::MustAlias)
       IsMustAlias = false;
-    if (AR == NoAlias)
+    if (AR == AliasResult::NoAlias)
       continue;
     if (Call->doesNotAccessMemory(ArgNo))
       continue;
     if (Call->onlyReadsMemory(ArgNo)) {
       R = ModRefInfo::Ref;
       continue;
     }
     // Not returning MustModRef since we have not seen all the arguments.

llvm/lib/Analysis/AliasAnalysisEvaluator.cpp

for (SetVector<Value *>::iterator I1 = Pointers.begin(), E = Pointers.end();
     for (SetVector<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) {
       auto I2Size = LocationSize::afterPointer();
       Type *I2ElTy = cast<PointerType>((*I2)->getType())->getElementType();
       if (I2ElTy->isSized())
         I2Size = LocationSize::precise(DL.getTypeStoreSize(I2ElTy));
 
       AliasResult AR = AA.alias(*I1, I1Size, *I2, I2Size);
       switch (AR) {
-      case NoAlias:
+      case AliasResult::NoAlias:
         PrintResults(AR, PrintNoAlias, *I1, *I2, F.getParent());
         ++NoAliasCount;
         break;
-      case MayAlias:
+      case AliasResult::MayAlias:
         PrintResults(AR, PrintMayAlias, *I1, *I2, F.getParent());
         ++MayAliasCount;
         break;
-      case PartialAlias:
+      case AliasResult::PartialAlias:
         PrintResults(AR, PrintPartialAlias, *I1, *I2, F.getParent());
         ++PartialAliasCount;
         break;
-      case MustAlias:
+      case AliasResult::MustAlias:
         PrintResults(AR, PrintMustAlias, *I1, *I2, F.getParent());
         ++MustAliasCount;
         break;
       }
     }
   }
 
   if (EvalAAMD) {
     // iterate over all pairs of load, store
     for (Value *Load : Loads) {
       for (Value *Store : Stores) {
         AliasResult AR = AA.alias(MemoryLocation::get(cast<LoadInst>(Load)),
                                   MemoryLocation::get(cast<StoreInst>(Store)));
         switch (AR) {
-        case NoAlias:
+        case AliasResult::NoAlias:
           PrintLoadStoreResults(AR, PrintNoAlias, Load, Store, F.getParent());
           ++NoAliasCount;
           break;
-        case MayAlias:
+        case AliasResult::MayAlias:
           PrintLoadStoreResults(AR, PrintMayAlias, Load, Store, F.getParent());
           ++MayAliasCount;
           break;
-        case PartialAlias:
+        case AliasResult::PartialAlias:
           PrintLoadStoreResults(AR, PrintPartialAlias, Load, Store, F.getParent());
           ++PartialAliasCount;
           break;
-        case MustAlias:
+        case AliasResult::MustAlias:
           PrintLoadStoreResults(AR, PrintMustAlias, Load, Store, F.getParent());
           ++MustAliasCount;
           break;
         }
       }
     }
 
     // iterate over all pairs of store, store
     for (SetVector<Value *>::iterator I1 = Stores.begin(), E = Stores.end();
          I1 != E; ++I1) {
       for (SetVector<Value *>::iterator I2 = Stores.begin(); I2 != I1; ++I2) {
         AliasResult AR = AA.alias(MemoryLocation::get(cast<StoreInst>(*I1)),
                                   MemoryLocation::get(cast<StoreInst>(*I2)));
         switch (AR) {
-        case NoAlias:
+        case AliasResult::NoAlias:
           PrintLoadStoreResults(AR, PrintNoAlias, *I1, *I2, F.getParent());
           ++NoAliasCount;
           break;
-        case MayAlias:
+        case AliasResult::MayAlias:
           PrintLoadStoreResults(AR, PrintMayAlias, *I1, *I2, F.getParent());
           ++MayAliasCount;
           break;
-        case PartialAlias:
+        case AliasResult::PartialAlias:
           PrintLoadStoreResults(AR, PrintPartialAlias, *I1, *I2, F.getParent());
           ++PartialAliasCount;
           break;
-        case MustAlias:
+        case AliasResult::MustAlias:
           PrintLoadStoreResults(AR, PrintMustAlias, *I1, *I2, F.getParent());
           ++MustAliasCount;
           break;
         }
       }
     }
   }
 

llvm/lib/Analysis/AliasSetTracker.cpp

if (Alias == SetMustAlias) {
     // Check that these two merged sets really are must aliases.  Since both
     // used to be must-alias sets, we can just check any pointer from each set
     // for aliasing.
     AliasAnalysis &AA = AST.getAliasAnalysis();
     PointerRec *L = getSomePointer();
     PointerRec *R = AS.getSomePointer();
 
     // If the pointers are not a must-alias pair, this set becomes a may alias.
-    if (AA.alias(MemoryLocation(L->getValue(), L->getSize(), L->getAAInfo()),
-                 MemoryLocation(R->getValue(), R->getSize(), R->getAAInfo())) !=
-        MustAlias)
+    if (!AA.isMustAlias(
+            MemoryLocation(L->getValue(), L->getSize(), L->getAAInfo()),
+            MemoryLocation(R->getValue(), R->getSize(), R->getAAInfo())))
       Alias = SetMayAlias;
   }
 
   if (Alias == SetMayAlias) {
     if (WasMustAlias)
       AST.TotalMayAliasSetSize += size();
     if (AS.Alias == SetMustAlias)
       AST.TotalMayAliasSetSize += AS.size();
void AliasSet::addPointer(AliasSetTracker &AST, PointerRec &Entry,
   // Check to see if we have to downgrade to _may_ alias.
   if (isMustAlias())
     if (PointerRec *P = getSomePointer()) {
       if (!KnownMustAlias) {
         AliasAnalysis &AA = AST.getAliasAnalysis();
         AliasResult Result = AA.alias(
             MemoryLocation(P->getValue(), P->getSize(), P->getAAInfo()),
             MemoryLocation(Entry.getValue(), Size, AAInfo));
-        if (Result != MustAlias) {
+        if (Result != AliasResult::MustAlias) {
           Alias = SetMayAlias;
           AST.TotalMayAliasSetSize += size();
         }
-        assert(Result != NoAlias && "Cannot be part of must set!");
+        assert(Result != AliasResult::NoAlias && "Cannot be part of must set!");
       } else if (!SkipSizeUpdate)
         P->updateSizeAndAAInfo(Size, AAInfo);
     }
 
   Entry.setAliasSet(this);
   Entry.updateSizeAndAAInfo(Size, AAInfo);
 
   // Add it to the end of the list...

 /// aliasesPointer - If the specified pointer "may" (or must) alias one of the
 /// members in the set return the appropriate AliasResult. Otherwise return
 /// NoAlias.
 ///
 AliasResult AliasSet::aliasesPointer(const Value *Ptr, LocationSize Size,
                                      const AAMDNodes &AAInfo,
                                      AliasAnalysis &AA) const {
   if (AliasAny)
-    return MayAlias;
+    return AliasResult::MayAlias;
 
   if (Alias == SetMustAlias) {
     assert(UnknownInsts.empty() && "Illegal must alias set!");
 
     // If this is a set of MustAliases, only check to see if the pointer aliases
     // SOME value in the set.
     PointerRec *SomePtr = getSomePointer();
     assert(SomePtr && "Empty must-alias set??");
     return AA.alias(MemoryLocation(SomePtr->getValue(), SomePtr->getSize(),
                                    SomePtr->getAAInfo()),
                     MemoryLocation(Ptr, Size, AAInfo));
   }
 
   // If this is a may-alias set, we have to check all of the pointers in the set
   // to be sure it doesn't alias the set...
-  for (iterator I = begin(), E = end(); I != E; ++I)
-    if (AliasResult AR = AA.alias(
-            MemoryLocation(Ptr, Size, AAInfo),
-            MemoryLocation(I.getPointer(), I.getSize(), I.getAAInfo())))
+  for (iterator I = begin(), E = end(); I != E; ++I) {
+    AliasResult AR =
+        AA.alias(MemoryLocation(Ptr, Size, AAInfo),
+                 MemoryLocation(I.getPointer(), I.getSize(), I.getAAInfo()));
+    if (AR != AliasResult::NoAlias)
       return AR;
+  }
 
   // Check the unknown instructions...
   if (!UnknownInsts.empty()) {
     for (unsigned i = 0, e = UnknownInsts.size(); i != e; ++i)
       if (auto *Inst = getUnknownInst(i))
         if (isModOrRefSet(
                 AA.getModRefInfo(Inst, MemoryLocation(Ptr, Size, AAInfo))))
-          return MayAlias;
+          return AliasResult::MayAlias;
   }
 
-  return NoAlias;
+  return AliasResult::NoAlias;
 }
 
 bool AliasSet::aliasesUnknownInst(const Instruction *Inst,
                                   AliasAnalysis &AA) const {
 
   if (AliasAny)
     return true;
 
AliasSet *AliasSetTracker::mergeAliasSetsForPointer(const Value *Ptr,
                                                     bool &MustAliasAll) {
   AliasSet *FoundSet = nullptr;
   MustAliasAll = true;
   for (AliasSet &AS : llvm::make_early_inc_range(*this)) {
     if (AS.Forward)
       continue;
 
     AliasResult AR = AS.aliasesPointer(Ptr, Size, AAInfo, AA);
-    if (AR == NoAlias)
+    if (AR == AliasResult::NoAlias)
       continue;
 
-    if (AR != MustAlias)
+    if (AR != AliasResult::MustAlias)
       MustAliasAll = false;
 
     if (!FoundSet) {
       // If this is the first alias set ptr can go into, remember it.
       FoundSet = &AS;
     } else {
       // Otherwise, we must merge the sets.
       FoundSet->mergeSetIn(AS, *this);

llvm/lib/Analysis/BasicAliasAnalysis.cpp

for (auto CI = Call->data_operands_begin(), CE = Call->data_operands_end();
       if (Call->doesNotAccessMemory(OperandNo))
         continue;
 
       // If this is a no-capture pointer argument, see if we can tell that it
       // is impossible to alias the pointer we're checking.
       AliasResult AR = getBestAAResults().alias(
           MemoryLocation::getBeforeOrAfter(*CI),
           MemoryLocation::getBeforeOrAfter(Object), AAQI);
-      if (AR != MustAlias)
+      if (AR != AliasResult::MustAlias)
         IsMustAlias = false;
       // Operand doesn't alias 'Object', continue looking for other aliases
-      if (AR == NoAlias)
+      if (AR == AliasResult::NoAlias)
         continue;
       // Operand aliases 'Object', but call doesn't modify it. Strengthen
       // initial assumption and keep looking in case if there are more aliases.
       if (Call->onlyReadsMemory(OperandNo)) {
         Result = setRef(Result);
         continue;
       }
       // Operand aliases 'Object' but call only writes into it.
ModRefInfo BasicAAResult::getModRefInfo(const CallBase *Call,
   // modify any IR visible value.  This is only valid because we assume these
   // routines do not read values visible in the IR.  TODO: Consider special
   // casing realloc and strdup routines which access only their arguments as
   // well.  Or alternatively, replace all of this with inaccessiblememonly once
   // that's implemented fully.
   if (isMallocOrCallocLikeFn(Call, &TLI)) {
     // Be conservative if the accessed pointer may alias the allocation -
     // fallback to the generic handling below.
-    if (getBestAAResults().alias(MemoryLocation::getBeforeOrAfter(Call),
-                                 Loc, AAQI) == NoAlias)
+    if (getBestAAResults().alias(MemoryLocation::getBeforeOrAfter(Call), Loc,
+                                 AAQI) == AliasResult::NoAlias)
       return ModRefInfo::NoModRef;
   }
 
   // The semantics of memcpy intrinsics either exactly overlap or do not
   // overlap, i.e., source and destination of any given memcpy are either
   // no-alias or must-alias.
   if (auto *Inst = dyn_cast<AnyMemCpyInst>(Call)) {
     AliasResult SrcAA =
         getBestAAResults().alias(MemoryLocation::getForSource(Inst), Loc, AAQI);
     AliasResult DestAA =
         getBestAAResults().alias(MemoryLocation::getForDest(Inst), Loc, AAQI);
     // It's also possible for Loc to alias both src and dest, or neither.
     ModRefInfo rv = ModRefInfo::NoModRef;
-    if (SrcAA != NoAlias)
+    if (SrcAA != AliasResult::NoAlias)
       rv = setRef(rv);
-    if (DestAA != NoAlias)
+    if (DestAA != AliasResult::NoAlias)
       rv = setMod(rv);
     return rv;
   }
 
   // Guard intrinsics are marked as arbitrarily writing so that proper control
   // dependencies are maintained but they never mods any particular memory
   // location.
   //
AliasResult BasicAAResult::aliasGEP(
 
   DecomposedGEP DecompGEP1 = DecomposeGEPExpression(GEP1, DL, &AC, DT);
   DecomposedGEP DecompGEP2 = DecomposeGEPExpression(V2, DL, &AC, DT);
 
   // Don't attempt to analyze the decomposed GEP if index scale is not a
   // compile-time constant.
   if (!DecompGEP1.HasCompileTimeConstantScale ||
       !DecompGEP2.HasCompileTimeConstantScale)
-    return MayAlias;
+    return AliasResult::MayAlias;
 
   assert(DecompGEP1.Base == UnderlyingV1 && DecompGEP2.Base == UnderlyingV2 &&
          "DecomposeGEPExpression returned a result different from "
          "getUnderlyingObject");
 
   // Subtract the GEP2 pointer from the GEP1 pointer to find out their
   // symbolic difference.
   DecompGEP1.Offset -= DecompGEP2.Offset;
   GetIndexDifference(DecompGEP1.VarIndices, DecompGEP2.VarIndices);
 
   // If an inbounds GEP would have to start from an out of bounds address
   // for the two to alias, then we can assume noalias.
   if (*DecompGEP1.InBounds && DecompGEP1.VarIndices.empty() &&
       V2Size.hasValue() && DecompGEP1.Offset.sge(V2Size.getValue()) &&
       isBaseOfObject(DecompGEP2.Base))
-    return NoAlias;
+    return AliasResult::NoAlias;
 
   if (isa<GEPOperator>(V2)) {
     // Symmetric case to above.
     if (*DecompGEP2.InBounds && DecompGEP1.VarIndices.empty() &&
         V1Size.hasValue() && DecompGEP1.Offset.sle(-V1Size.getValue()) &&
         isBaseOfObject(DecompGEP1.Base))
-    return NoAlias;
+      return AliasResult::NoAlias;
   }
 
   // For GEPs with identical offsets, we can preserve the size and AAInfo
   // when performing the alias check on the underlying objects.
   if (DecompGEP1.Offset == 0 && DecompGEP1.VarIndices.empty())
     return getBestAAResults().alias(
         MemoryLocation(UnderlyingV1, V1Size),
         MemoryLocation(UnderlyingV2, V2Size), AAQI);
 
   // Do the base pointers alias?
   AliasResult BaseAlias = getBestAAResults().alias(
       MemoryLocation::getBeforeOrAfter(UnderlyingV1),
       MemoryLocation::getBeforeOrAfter(UnderlyingV2), AAQI);
 
   // If we get a No or May, then return it immediately, no amount of analysis
   // will improve this situation.
-  if (BaseAlias != MustAlias) {
-    assert(BaseAlias == NoAlias || BaseAlias == MayAlias);
+  if (BaseAlias != AliasResult::MustAlias) {
+    assert(BaseAlias == AliasResult::NoAlias ||
+           BaseAlias == AliasResult::MayAlias);
     return BaseAlias;
   }
 
   // If there is a constant difference between the pointers, but the difference
   // is less than the size of the associated memory object, then we know
   // that the objects are partially overlapping.  If the difference is
   // greater, we know they do not overlap.
   if (DecompGEP1.Offset != 0 && DecompGEP1.VarIndices.empty()) {
if (VLeftSize.hasValue()) {
             Off.ule(INT64_MAX)) {
           // Memory referenced by right pointer is nested. Save the offset in
           // cache.
           const uint64_t RSize = VRightSize.getValue();
           if ((Off + RSize).ule(LSize))
             AAQI.setClobberOffset(LeftPtr, RightPtr, LSize, RSize,
                                   Off.getSExtValue());
         }
-        return PartialAlias;
+        return AliasResult::PartialAlias;
       }
-      return NoAlias;
+      return AliasResult::NoAlias;
     }
   }
 
   if (!DecompGEP1.VarIndices.empty()) {
     APInt GCD;
     bool AllNonNegative = DecompGEP1.Offset.isNonNegative();
     bool AllNonPositive = DecompGEP1.Offset.isNonPositive();
     for (unsigned i = 0, e = DecompGEP1.VarIndices.size(); i != e; ++i) {
if (!DecompGEP1.VarIndices.empty()) {
     // [ModOffset..ModOffset+V1Size) and [0..V2Size). If the first access fits
     // into the range [V2Size..GCD), then we know they cannot overlap.
     APInt ModOffset = DecompGEP1.Offset.srem(GCD);
     if (ModOffset.isNegative())
       ModOffset += GCD; // We want mod, not rem.
     if (V1Size.hasValue() && V2Size.hasValue() &&
         ModOffset.uge(V2Size.getValue()) &&
         (GCD - ModOffset).uge(V1Size.getValue()))
-      return NoAlias;
+      return AliasResult::NoAlias;
 
     // If we know all the variables are non-negative, then the total offset is
     // also non-negative and >= DecompGEP1.Offset. We have the following layout:
     // [0, V2Size) ... [TotalOffset, TotalOffer+V1Size]
     // If DecompGEP1.Offset >= V2Size, the accesses don't alias.
     if (AllNonNegative && V2Size.hasValue() &&
         DecompGEP1.Offset.uge(V2Size.getValue()))
-      return NoAlias;
+      return AliasResult::NoAlias;
     // Similarly, if the variables are non-positive, then the total offset is
     // also non-positive and <= DecompGEP1.Offset. We have the following layout:
     // [TotalOffset, TotalOffset+V1Size) ... [0, V2Size)
     // If -DecompGEP1.Offset >= V1Size, the accesses don't alias.
     if (AllNonPositive && V1Size.hasValue() &&
         (-DecompGEP1.Offset).uge(V1Size.getValue()))
-      return NoAlias;
+      return AliasResult::NoAlias;
 
     if (V1Size.hasValue() && V2Size.hasValue()) {
       // Try to determine whether abs(VarIndex) > 0.
       Optional<APInt> MinAbsVarIndex;
       if (DecompGEP1.VarIndices.size() == 1) {
         // VarIndex = Scale*V. If V != 0 then abs(VarIndex) >= abs(Scale).
         const VariableGEPIndex &Var = DecompGEP1.VarIndices[0];
         if (isKnownNonZero(Var.V, DL, 0, &AC, Var.CxtI, DT))
if (V1Size.hasValue() && V2Size.hasValue()) {
       if (MinAbsVarIndex) {
         // The constant offset will have added at least +/-MinAbsVarIndex to it.
         APInt OffsetLo = DecompGEP1.Offset - *MinAbsVarIndex;
         APInt OffsetHi = DecompGEP1.Offset + *MinAbsVarIndex;
         // Check that an access at OffsetLo or lower, and an access at OffsetHi
         // or higher both do not alias.
         if (OffsetLo.isNegative() && (-OffsetLo).uge(V1Size.getValue()) &&
             OffsetHi.isNonNegative() && OffsetHi.uge(V2Size.getValue()))
-          return NoAlias;
+          return AliasResult::NoAlias;
       }
     }
 
     if (constantOffsetHeuristic(DecompGEP1.VarIndices, V1Size, V2Size,
                                 DecompGEP1.Offset, &AC, DT))
-      return NoAlias;
+      return AliasResult::NoAlias;
   }
 
   // Statically, we can see that the base objects are the same, but the
   // pointers have dynamic offsets which we can't resolve. And none of our
   // little tricks above worked.
-  return MayAlias;
+  return AliasResult::MayAlias;
 }
 
 static AliasResult MergeAliasResults(AliasResult A, AliasResult B) {
   // If the results agree, take it.
   if (A == B)
     return A;
   // A mix of PartialAlias and MustAlias is PartialAlias.
-  if ((A == PartialAlias && B == MustAlias) ||
-      (B == PartialAlias && A == MustAlias))
-    return PartialAlias;
+  if ((A == AliasResult::PartialAlias && B == AliasResult::MustAlias) ||
+      (B == AliasResult::PartialAlias && A == AliasResult::MustAlias))
+    return AliasResult::PartialAlias;
   // Otherwise, we don't know anything.
-  return MayAlias;
+  return AliasResult::MayAlias;
 }
 
 /// Provides a bunch of ad-hoc rules to disambiguate a Select instruction
 /// against another.
 AliasResult
 BasicAAResult::aliasSelect(const SelectInst *SI, LocationSize SISize,
                            const Value *V2, LocationSize V2Size,
                            AAQueryInfo &AAQI) {
   // If the values are Selects with the same condition, we can do a more precise
   // check: just check for aliases between the values on corresponding arms.
   if (const SelectInst *SI2 = dyn_cast<SelectInst>(V2))
     if (SI->getCondition() == SI2->getCondition()) {
       AliasResult Alias = getBestAAResults().alias(
           MemoryLocation(SI->getTrueValue(), SISize),
           MemoryLocation(SI2->getTrueValue(), V2Size), AAQI);
-      if (Alias == MayAlias)
-        return MayAlias;
+      if (Alias == AliasResult::MayAlias)
+        return AliasResult::MayAlias;
       AliasResult ThisAlias = getBestAAResults().alias(
           MemoryLocation(SI->getFalseValue(), SISize),
           MemoryLocation(SI2->getFalseValue(), V2Size), AAQI);
       return MergeAliasResults(ThisAlias, Alias);
     }
 
   // If both arms of the Select node NoAlias or MustAlias V2, then returns
   // NoAlias / MustAlias. Otherwise, returns MayAlias.
   AliasResult Alias = getBestAAResults().alias(
       MemoryLocation(V2, V2Size),
       MemoryLocation(SI->getTrueValue(), SISize), AAQI);
-  if (Alias == MayAlias)
-    return MayAlias;
+  if (Alias == AliasResult::MayAlias)
+    return AliasResult::MayAlias;
 
   AliasResult ThisAlias = getBestAAResults().alias(
       MemoryLocation(V2, V2Size),
       MemoryLocation(SI->getFalseValue(), SISize), AAQI);
   return MergeAliasResults(ThisAlias, Alias);
 }
 
 /// Provide a bunch of ad-hoc rules to disambiguate a PHI instruction against
if (PN2->getParent() == PN->getParent()) {
             MemoryLocation(PN->getIncomingValue(i), PNSize),
             MemoryLocation(
                 PN2->getIncomingValueForBlock(PN->getIncomingBlock(i)), V2Size),
             AAQI);
         if (Alias)
           *Alias = MergeAliasResults(*Alias, ThisAlias);
         else
           Alias = ThisAlias;
-        if (*Alias == MayAlias)
+        if (*Alias == AliasResult::MayAlias)
           break;
       }
       return *Alias;
     }
 
   SmallVector<Value *, 4> V1Srcs;
   // If a phi operand recurses back to the phi, we can still determine NoAlias
   // if we don't alias the underlying objects of the other phi operands, as we
AliasResult BasicAAResult::aliasPHI(const PHINode *PN, LocationSize PNSize,
   if (PV) {
     // If we have PhiValues then use it to get the underlying phi values.
     const PhiValues::ValueSet &PhiValueSet = PV->getValuesForPhi(PN);
     // If we have more phi values than the search depth then return MayAlias
     // conservatively to avoid compile time explosion. The worst possible case
     // is if both sides are PHI nodes. In which case, this is O(m x n) time
     // where 'm' and 'n' are the number of PHI sources.
     if (PhiValueSet.size() > MaxLookupSearchDepth)
-      return MayAlias;
+      return AliasResult::MayAlias;
     // Add the values to V1Srcs
     for (Value *PV1 : PhiValueSet) {
       if (CheckForRecPhi(PV1))
         continue;
       V1Srcs.push_back(PV1);
     }
   } else {
     // If we don't have PhiInfo then just look at the operands of the phi itself
     // FIXME: Remove this once we can guarantee that we have PhiInfo always
     SmallPtrSet<Value *, 4> UniqueSrc;
     Value *OnePhi = nullptr;
     for (Value *PV1 : PN->incoming_values()) {
       if (isa<PHINode>(PV1)) {
         if (OnePhi && OnePhi != PV1) {
           // To control potential compile time explosion, we choose to be
           // conserviate when we have more than one Phi input.  It is important
           // that we handle the single phi case as that lets us handle LCSSA
           // phi nodes and (combined with the recursive phi handling) simple
           // pointer induction variable patterns.
-          return MayAlias;
+          return AliasResult::MayAlias;
         }
         OnePhi = PV1;
       }
 
       if (CheckForRecPhi(PV1))
         continue;
 
       if (UniqueSrc.insert(PV1).second)
         V1Srcs.push_back(PV1);
     }
 
     if (OnePhi && UniqueSrc.size() > 1)
       // Out of an abundance of caution, allow only the trivial lcssa and
       // recursive phi cases.
-      return MayAlias;
+      return AliasResult::MayAlias;
   }
 
   // If V1Srcs is empty then that means that the phi has no underlying non-phi
   // value. This should only be possible in blocks unreachable from the entry
   // block, but return MayAlias just in case.
   if (V1Srcs.empty())
-    return MayAlias;
+    return AliasResult::MayAlias;
 
   // If this PHI node is recursive, indicate that the pointer may be moved
   // across iterations. We can only prove NoAlias if different underlying
   // objects are involved.
   if (isRecursive)
     PNSize = LocationSize::beforeOrAfterPointer();
 
   // In the recursive alias queries below, we may compare values from two
AliasResult BasicAAResult::aliasPHI(const PHINode *PN, LocationSize PNSize,
   AAQueryInfo *UseAAQI = BlockInserted ? &NewAAQI : &AAQI;
 
   AliasResult Alias = getBestAAResults().alias(
       MemoryLocation(V2, V2Size),
       MemoryLocation(V1Srcs[0], PNSize), *UseAAQI);
 
   // Early exit if the check of the first PHI source against V2 is MayAlias.
   // Other results are not possible.
-  if (Alias == MayAlias)
-    return MayAlias;
+  if (Alias == AliasResult::MayAlias)
+    return AliasResult::MayAlias;
   // With recursive phis we cannot guarantee that MustAlias/PartialAlias will
   // remain valid to all elements and needs to conservatively return MayAlias.
-  if (isRecursive && Alias != NoAlias)
-    return MayAlias;
+  if (isRecursive && Alias != AliasResult::NoAlias)
+    return AliasResult::MayAlias;
 
   // If all sources of the PHI node NoAlias or MustAlias V2, then returns
   // NoAlias / MustAlias. Otherwise, returns MayAlias.
   for (unsigned i = 1, e = V1Srcs.size(); i != e; ++i) {
     Value *V = V1Srcs[i];
 
     AliasResult ThisAlias = getBestAAResults().alias(
         MemoryLocation(V2, V2Size), MemoryLocation(V, PNSize), *UseAAQI);
     Alias = MergeAliasResults(ThisAlias, Alias);
-    if (Alias == MayAlias)
+    if (Alias == AliasResult::MayAlias)
       break;
   }
 
   return Alias;
 }
 
 /// Provides a bunch of ad-hoc rules to disambiguate in common cases, such as
 /// array references.
 AliasResult BasicAAResult::aliasCheck(const Value *V1, LocationSize V1Size,
                                       const Value *V2, LocationSize V2Size,
                                       AAQueryInfo &AAQI) {
   // If either of the memory references is empty, it doesn't matter what the
   // pointer values are.
   if (V1Size.isZero() || V2Size.isZero())
-    return NoAlias;
+    return AliasResult::NoAlias;
 
   // Strip off any casts if they exist.
   V1 = V1->stripPointerCastsForAliasAnalysis();
   V2 = V2->stripPointerCastsForAliasAnalysis();
 
   // If V1 or V2 is undef, the result is NoAlias because we can always pick a
   // value for undef that aliases nothing in the program.
   if (isa<UndefValue>(V1) || isa<UndefValue>(V2))
-    return NoAlias;
+    return AliasResult::NoAlias;
 
   // Are we checking for alias of the same value?
   // Because we look 'through' phi nodes, we could look at "Value" pointers from
   // different iterations. We must therefore make sure that this is not the
   // case. The function isValueEqualInPotentialCycles ensures that this cannot
   // happen by looking at the visited phi nodes and making sure they cannot
   // reach the value.
   if (isValueEqualInPotentialCycles(V1, V2))
-    return MustAlias;
+    return AliasResult::MustAlias;
 
   if (!V1->getType()->isPointerTy() || !V2->getType()->isPointerTy())
-    return NoAlias; // Scalars cannot alias each other
+    return AliasResult::NoAlias; // Scalars cannot alias each other
 
   // Figure out what objects these things are pointing to if we can.
   const Value *O1 = getUnderlyingObject(V1, MaxLookupSearchDepth);
   const Value *O2 = getUnderlyingObject(V2, MaxLookupSearchDepth);
 
   // Null values in the default address space don't point to any object, so they
   // don't alias any other pointer.
   if (const ConstantPointerNull *CPN = dyn_cast<ConstantPointerNull>(O1))
     if (!NullPointerIsDefined(&F, CPN->getType()->getAddressSpace()))
-      return NoAlias;
+      return AliasResult::NoAlias;
   if (const ConstantPointerNull *CPN = dyn_cast<ConstantPointerNull>(O2))
     if (!NullPointerIsDefined(&F, CPN->getType()->getAddressSpace()))
-      return NoAlias;
+      return AliasResult::NoAlias;
 
   if (O1 != O2) {
     // If V1/V2 point to two different objects, we know that we have no alias.
     if (isIdentifiedObject(O1) && isIdentifiedObject(O2))
-      return NoAlias;
+      return AliasResult::NoAlias;
 
     // Constant pointers can't alias with non-const isIdentifiedObject objects.
     if ((isa<Constant>(O1) && isIdentifiedObject(O2) && !isa<Constant>(O2)) ||
         (isa<Constant>(O2) && isIdentifiedObject(O1) && !isa<Constant>(O1)))
-      return NoAlias;
+      return AliasResult::NoAlias;
 
     // Function arguments can't alias with things that are known to be
     // unambigously identified at the function level.
     if ((isa<Argument>(O1) && isIdentifiedFunctionLocal(O2)) ||
         (isa<Argument>(O2) && isIdentifiedFunctionLocal(O1)))
-      return NoAlias;
+      return AliasResult::NoAlias;
 
     // If one pointer is the result of a call/invoke or load and the other is a
     // non-escaping local object within the same function, then we know the
     // object couldn't escape to a point where the call could return it.
     //
     // Note that if the pointers are in different functions, there are a
     // variety of complications. A call with a nocapture argument may still
     // temporary store the nocapture argument's value in a temporary memory
     // location if that memory location doesn't escape. Or it may pass a
     // nocapture value to other functions as long as they don't capture it.
     if (isEscapeSource(O1) &&
         isNonEscapingLocalObject(O2, &AAQI.IsCapturedCache))
-      return NoAlias;
+      return AliasResult::NoAlias;
     if (isEscapeSource(O2) &&
         isNonEscapingLocalObject(O1, &AAQI.IsCapturedCache))
-      return NoAlias;
+      return AliasResult::NoAlias;
   }
 
   // If the size of one access is larger than the entire object on the other
   // side, then we know such behavior is undefined and can assume no alias.
   bool NullIsValidLocation = NullPointerIsDefined(&F);
   if ((isObjectSmallerThan(
           O2, getMinimalExtentFrom(*V1, V1Size, DL, NullIsValidLocation), DL,
           TLI, NullIsValidLocation)) ||
       (isObjectSmallerThan(
           O1, getMinimalExtentFrom(*V2, V2Size, DL, NullIsValidLocation), DL,
           TLI, NullIsValidLocation)))
-    return NoAlias;
+    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
   // will always came after the other, as long as the underlying objects aren't
   // disjoint. We do this so that the rest of BasicAA does not have to deal
   // with accesses before the base pointer, and to improve cache utilization by
   // merging equivalent states.
   if (V1Size.mayBeBeforePointer() || V2Size.mayBeBeforePointer()) {
     V1Size = LocationSize::afterPointer();
     V2Size = LocationSize::afterPointer();
   }
 
   // FIXME: If this depth limit is hit, then we may cache sub-optimal results
   // for recursive queries. For this reason, this limit is chosen to be large
   // enough to be very rarely hit, while still being small enough to avoid
   // stack overflows.
   if (AAQI.Depth >= 512)
-    return MayAlias;
+    return AliasResult::MayAlias;
 
   // Check the cache before climbing up use-def chains. This also terminates
   // otherwise infinitely recursive queries.
   AAQueryInfo::LocPair Locs({V1, V1Size}, {V2, V2Size});
   if (V1 > V2)
     std::swap(Locs.first, Locs.second);
   const auto &Pair = AAQI.AliasCache.try_emplace(
-      Locs, AAQueryInfo::CacheEntry{NoAlias, 0});
+      Locs, AAQueryInfo::CacheEntry{AliasResult::NoAlias, 0});
   if (!Pair.second) {
     auto &Entry = Pair.first->second;
     if (!Entry.isDefinitive()) {
       // Remember that we used an assumption.
       ++Entry.NumAssumptionUses;
       ++AAQI.NumAssumptionUses;
     }
     return Entry.Result;
   }
 
   int OrigNumAssumptionUses = AAQI.NumAssumptionUses;
   unsigned OrigNumAssumptionBasedResults = AAQI.AssumptionBasedResults.size();
   AliasResult Result =
       aliasCheckRecursive(V1, V1Size, V2, V2Size, AAQI, O1, O2);
 
   auto It = AAQI.AliasCache.find(Locs);
   assert(It != AAQI.AliasCache.end() && "Must be in cache");
   auto &Entry = It->second;
 
   // Check whether a NoAlias assumption has been used, but disproven.
-  bool AssumptionDisproven = Entry.NumAssumptionUses > 0 && Result != NoAlias;
+  bool AssumptionDisproven =
+      Entry.NumAssumptionUses > 0 && Result != AliasResult::NoAlias;
   if (AssumptionDisproven)
-    Result = MayAlias;
+    Result = AliasResult::MayAlias;
 
   // This is a definitive result now, when considered as a root query.
   AAQI.NumAssumptionUses -= Entry.NumAssumptionUses;
   Entry.Result = Result;
   Entry.NumAssumptionUses = -1;
 
   // If the assumption has been disproven, remove any results that may have
   // been based on this assumption. Do this after the Entry updates above to
   // avoid iterator invalidation.
   if (AssumptionDisproven)
     while (AAQI.AssumptionBasedResults.size() > OrigNumAssumptionBasedResults)
       AAQI.AliasCache.erase(AAQI.AssumptionBasedResults.pop_back_val());
 
   // The result may still be based on assumptions higher up in the chain.
   // Remember it, so it can be purged from the cache later.
-  if (OrigNumAssumptionUses != AAQI.NumAssumptionUses && Result != MayAlias)
+  if (OrigNumAssumptionUses != AAQI.NumAssumptionUses &&
+      Result != AliasResult::MayAlias)
     AAQI.AssumptionBasedResults.push_back(Locs);
   return Result;
 }
 
 AliasResult BasicAAResult::aliasCheckRecursive(
     const Value *V1, LocationSize V1Size,
     const Value *V2, LocationSize V2Size,
     AAQueryInfo &AAQI, const Value *O1, const Value *O2) {
   if (const GEPOperator *GV1 = dyn_cast<GEPOperator>(V1)) {
     AliasResult Result = aliasGEP(GV1, V1Size, V2, V2Size, O1, O2, AAQI);
-    if (Result != MayAlias)
+    if (Result != AliasResult::MayAlias)
       return Result;
   } else if (const GEPOperator *GV2 = dyn_cast<GEPOperator>(V2)) {
     AliasResult Result = aliasGEP(GV2, V2Size, V1, V1Size, O2, O1, AAQI);
-    if (Result != MayAlias)
+    if (Result != AliasResult::MayAlias)
       return Result;
   }
 
   if (const PHINode *PN = dyn_cast<PHINode>(V1)) {
     AliasResult Result = aliasPHI(PN, V1Size, V2, V2Size, AAQI);
-    if (Result != MayAlias)
+    if (Result != AliasResult::MayAlias)
       return Result;
   } else if (const PHINode *PN = dyn_cast<PHINode>(V2)) {
     AliasResult Result = aliasPHI(PN, V2Size, V1, V1Size, AAQI);
-    if (Result != MayAlias)
+    if (Result != AliasResult::MayAlias)
       return Result;
   }
 
   if (const SelectInst *S1 = dyn_cast<SelectInst>(V1)) {
     AliasResult Result = aliasSelect(S1, V1Size, V2, V2Size, AAQI);
-    if (Result != MayAlias)
+    if (Result != AliasResult::MayAlias)
       return Result;
   } else if (const SelectInst *S2 = dyn_cast<SelectInst>(V2)) {
     AliasResult Result = aliasSelect(S2, V2Size, V1, V1Size, AAQI);
-    if (Result != MayAlias)
+    if (Result != AliasResult::MayAlias)
       return Result;
   }
 
   // If both pointers are pointing into the same object and one of them
   // accesses the entire object, then the accesses must overlap in some way.
   if (O1 == O2) {
     bool NullIsValidLocation = NullPointerIsDefined(&F);
     if (V1Size.isPrecise() && V2Size.isPrecise() &&
         (isObjectSize(O1, V1Size.getValue(), DL, TLI, NullIsValidLocation) ||
          isObjectSize(O2, V2Size.getValue(), DL, TLI, NullIsValidLocation)))
-      return PartialAlias;
+      return AliasResult::PartialAlias;
   }
 
-  return MayAlias;
+  return AliasResult::MayAlias;
 }
 
 /// Check whether two Values can be considered equivalent.
 ///
 /// In addition to pointer equivalence of \p V1 and \p V2 this checks whether
 /// they can not be part of a cycle in the value graph by looking at all
 /// visited phi nodes an making sure that the phis cannot reach the value. We
 /// have to do this because we are looking through phi nodes (That is we say

llvm/lib/Analysis/CFLAndersAliasAnalysis.cpp

 }
 
 AliasResult CFLAndersAAResult::query(const MemoryLocation &LocA,
                                      const MemoryLocation &LocB) {
   auto *ValA = LocA.Ptr;
   auto *ValB = LocB.Ptr;
 
   if (!ValA->getType()->isPointerTy() || !ValB->getType()->isPointerTy())
-    return NoAlias;
+    return AliasResult::NoAlias;
 
   auto *Fn = parentFunctionOfValue(ValA);
   if (!Fn) {
     Fn = parentFunctionOfValue(ValB);
     if (!Fn) {
       // The only times this is known to happen are when globals + InlineAsm are
       // involved
       LLVM_DEBUG(
           dbgs()
           << "CFLAndersAA: could not extract parent function information.\n");
-      return MayAlias;
+      return AliasResult::MayAlias;
     }
   } else {
     assert(!parentFunctionOfValue(ValB) || parentFunctionOfValue(ValB) == Fn);
   }
 
   assert(Fn != nullptr);
   auto &FunInfo = ensureCached(*Fn);
 
   // AliasMap lookup
   if (FunInfo->mayAlias(ValA, LocA.Size, ValB, LocB.Size))
-    return MayAlias;
-  return NoAlias;
+    return AliasResult::MayAlias;
+  return AliasResult::NoAlias;
 }
 
 AliasResult CFLAndersAAResult::alias(const MemoryLocation &LocA,
                                      const MemoryLocation &LocB,
                                      AAQueryInfo &AAQI) {
   if (LocA.Ptr == LocB.Ptr)
-    return MustAlias;
+    return AliasResult::MustAlias;
 
   // Comparisons between global variables and other constants should be
   // handled by BasicAA.
   // CFLAndersAA may report NoAlias when comparing a GlobalValue and
   // ConstantExpr, but every query needs to have at least one Value tied to a
   // Function, and neither GlobalValues nor ConstantExprs are.
   if (isa<Constant>(LocA.Ptr) && isa<Constant>(LocB.Ptr))
     return AAResultBase::alias(LocA, LocB, AAQI);
 
   AliasResult QueryResult = query(LocA, LocB);
-  if (QueryResult == MayAlias)
+  if (QueryResult == AliasResult::MayAlias)
     return AAResultBase::alias(LocA, LocB, AAQI);
 
   return QueryResult;
 }
 
 AnalysisKey CFLAndersAA::Key;
 
 CFLAndersAAResult CFLAndersAA::run(Function &F, FunctionAnalysisManager &AM) {

llvm/lib/Analysis/CFLSteensAliasAnalysis.cpp

 }
 
 AliasResult CFLSteensAAResult::query(const MemoryLocation &LocA,
                                      const MemoryLocation &LocB) {
   auto *ValA = const_cast<Value *>(LocA.Ptr);
   auto *ValB = const_cast<Value *>(LocB.Ptr);
 
   if (!ValA->getType()->isPointerTy() || !ValB->getType()->isPointerTy())
-    return NoAlias;
+    return AliasResult::NoAlias;
 
   Function *Fn = nullptr;
   Function *MaybeFnA = const_cast<Function *>(parentFunctionOfValue(ValA));
   Function *MaybeFnB = const_cast<Function *>(parentFunctionOfValue(ValB));
   if (!MaybeFnA && !MaybeFnB) {
     // The only times this is known to happen are when globals + InlineAsm are
     // involved
     LLVM_DEBUG(
         dbgs()
         << "CFLSteensAA: could not extract parent function information.\n");
-    return MayAlias;
+    return AliasResult::MayAlias;
   }
 
   if (MaybeFnA) {
     Fn = MaybeFnA;
     assert((!MaybeFnB || MaybeFnB == MaybeFnA) &&
            "Interprocedural queries not supported");
   } else {
     Fn = MaybeFnB;
   }
 
   assert(Fn != nullptr);
   auto &MaybeInfo = ensureCached(Fn);
   assert(MaybeInfo.hasValue());
 
   auto &Sets = MaybeInfo->getStratifiedSets();
   auto MaybeA = Sets.find(InstantiatedValue{ValA, 0});
   if (!MaybeA.hasValue())
-    return MayAlias;
+    return AliasResult::MayAlias;
 
   auto MaybeB = Sets.find(InstantiatedValue{ValB, 0});
   if (!MaybeB.hasValue())
-    return MayAlias;
+    return AliasResult::MayAlias;
 
   auto SetA = *MaybeA;
   auto SetB = *MaybeB;
   auto AttrsA = Sets.getLink(SetA.Index).Attrs;
   auto AttrsB = Sets.getLink(SetB.Index).Attrs;
 
   // If both values are local (meaning the corresponding set has attribute
   // AttrNone or AttrEscaped), then we know that CFLSteensAA fully models them:
   // they may-alias each other if and only if they are in the same set.
   // If at least one value is non-local (meaning it either is global/argument or
   // it comes from unknown sources like integer cast), the situation becomes a
   // bit more interesting. We follow three general rules described below:
   // - Non-local values may alias each other
   // - AttrNone values do not alias any non-local values
   // - AttrEscaped do not alias globals/arguments, but they may alias
   // AttrUnknown values
   if (SetA.Index == SetB.Index)
-    return MayAlias;
+    return AliasResult::MayAlias;
   if (AttrsA.none() || AttrsB.none())
-    return NoAlias;
+    return AliasResult::NoAlias;
   if (hasUnknownOrCallerAttr(AttrsA) || hasUnknownOrCallerAttr(AttrsB))
-    return MayAlias;
+    return AliasResult::MayAlias;
   if (isGlobalOrArgAttr(AttrsA) && isGlobalOrArgAttr(AttrsB))
-    return MayAlias;
-  return NoAlias;
+    return AliasResult::MayAlias;
+  return AliasResult::NoAlias;
 }
 
 AnalysisKey CFLSteensAA::Key;
 
 CFLSteensAAResult CFLSteensAA::run(Function &F, FunctionAnalysisManager &AM) {
   auto GetTLI = [&AM](Function &F) -> const TargetLibraryInfo & {
     return AM.getResult<TargetLibraryAnalysis>(F);
   };

llvm/lib/Analysis/DependenceAnalysis.cpp

static AliasResult underlyingObjectsAlias(AAResults *AA,
                                           const MemoryLocation &LocA,
                                           const MemoryLocation &LocB) {
   // Check the original locations (minus size) for noalias, which can happen for
   // tbaa, incompatible underlying object locations, etc.
   MemoryLocation LocAS =
       MemoryLocation::getBeforeOrAfter(LocA.Ptr, LocA.AATags);
   MemoryLocation LocBS =
       MemoryLocation::getBeforeOrAfter(LocB.Ptr, LocB.AATags);
-  if (AA->alias(LocAS, LocBS) == NoAlias)
-    return NoAlias;
+  if (AA->isNoAlias(LocAS, LocBS))
+    return AliasResult::NoAlias;
 
   // Check the underlying objects are the same
   const Value *AObj = getUnderlyingObject(LocA.Ptr);
   const Value *BObj = getUnderlyingObject(LocB.Ptr);
 
   // If the underlying objects are the same, they must alias
   if (AObj == BObj)
-    return MustAlias;
+    return AliasResult::MustAlias;
 
   // We may have hit the recursion limit for underlying objects, or have
   // underlying objects where we don't know they will alias.
   if (!isIdentifiedObject(AObj) || !isIdentifiedObject(BObj))
-    return MayAlias;
+    return AliasResult::MayAlias;
 
   // Otherwise we know the objects are different and both identified objects so
   // must not alias.
-  return NoAlias;
+  return AliasResult::NoAlias;
 }
 
 
 // Returns true if the load or store can be analyzed. Atomic and volatile
 // operations have properties which this analysis does not understand.
 static
 bool isLoadOrStore(const Instruction *I) {
   if (const LoadInst *LI = dyn_cast<LoadInst>(I))
DependenceInfo::depends(Instruction *Src, Instruction *Dst,
   assert(isLoadOrStore(Src) && "instruction is not load or store");
   assert(isLoadOrStore(Dst) && "instruction is not load or store");
   Value *SrcPtr = getLoadStorePointerOperand(Src);
   Value *DstPtr = getLoadStorePointerOperand(Dst);
 
   switch (underlyingObjectsAlias(AA, F->getParent()->getDataLayout(),
                                  MemoryLocation::get(Dst),
                                  MemoryLocation::get(Src))) {
-  case MayAlias:
-  case PartialAlias:
+  case AliasResult::MayAlias:
+  case AliasResult::PartialAlias:
     // cannot analyse objects if we don't understand their aliasing.
     LLVM_DEBUG(dbgs() << "can't analyze may or partial alias\n");
     return std::make_unique<Dependence>(Src, Dst);
-  case NoAlias:
+  case AliasResult::NoAlias:
     // If the objects noalias, they are distinct, accesses are independent.
     LLVM_DEBUG(dbgs() << "no alias\n");
     return nullptr;
-  case MustAlias:
+  case AliasResult::MustAlias:
     break; // The underlying objects alias; test accesses for dependence.
   }
 
   // establish loop nesting levels
   establishNestingLevels(Src, Dst);
   LLVM_DEBUG(dbgs() << "    common nesting levels = " << CommonLevels << "\n");
   LLVM_DEBUG(dbgs() << "    maximum nesting levels = " << MaxLevels << "\n");
 
const SCEV *DependenceInfo::getSplitIteration(const Dependence &Dep,
   Instruction *Src = Dep.getSrc();
   Instruction *Dst = Dep.getDst();
   assert(Src->mayReadFromMemory() || Src->mayWriteToMemory());
   assert(Dst->mayReadFromMemory() || Dst->mayWriteToMemory());
   assert(isLoadOrStore(Src));
   assert(isLoadOrStore(Dst));
   Value *SrcPtr = getLoadStorePointerOperand(Src);
   Value *DstPtr = getLoadStorePointerOperand(Dst);
-  assert(underlyingObjectsAlias(AA, F->getParent()->getDataLayout(),
-                                MemoryLocation::get(Dst),
-                                MemoryLocation::get(Src)) == MustAlias);
+  assert(underlyingObjectsAlias(
+             AA, F->getParent()->getDataLayout(), MemoryLocation::get(Dst),
+             MemoryLocation::get(Src)) == AliasResult::MustAlias);
 
   // establish loop nesting levels
   establishNestingLevels(Src, Dst);
 
   FullDependence Result(Src, Dst, false, CommonLevels);
 
   unsigned Pairs = 1;
   SmallVector<Subscript, 2> Pair(Pairs);

llvm/lib/Analysis/GlobalsModRef.cpp

if (GV1 || GV2) {
     if (GV1 && !NonAddressTakenGlobals.count(GV1))
       GV1 = nullptr;
     if (GV2 && !NonAddressTakenGlobals.count(GV2))
       GV2 = nullptr;
 
     // If the two pointers are derived from two different non-addr-taken
     // globals we know these can't alias.
     if (GV1 && GV2 && GV1 != GV2)
-      return NoAlias;
+      return AliasResult::NoAlias;
 
     // If one is and the other isn't, it isn't strictly safe but we can fake
     // this result if necessary for performance. This does not appear to be
     // a common problem in practice.
     if (EnableUnsafeGlobalsModRefAliasResults)
       if ((GV1 || GV2) && GV1 != GV2)
-        return NoAlias;
+        return AliasResult::NoAlias;
 
     // Check for a special case where a non-escaping global can be used to
     // conclude no-alias.
     if ((GV1 || GV2) && GV1 != GV2) {
       const GlobalValue *GV = GV1 ? GV1 : GV2;
       const Value *UV = GV1 ? UV2 : UV1;
       if (isNonEscapingGlobalNoAlias(GV, UV))
-        return NoAlias;
+        return AliasResult::NoAlias;
     }
 
     // Otherwise if they are both derived from the same addr-taken global, we
     // can't know the two accesses don't overlap.
   }
 
   // These pointers may be based on the memory owned by an indirect global.  If
   // so, we may be able to handle this.  First check to see if the base pointer
if (!GV1)
     GV1 = AllocsForIndirectGlobals.lookup(UV1);
   if (!GV2)
     GV2 = AllocsForIndirectGlobals.lookup(UV2);
 
   // Now that we know whether the two pointers are related to indirect globals,
   // use this to disambiguate the pointers. If the pointers are based on
   // different indirect globals they cannot alias.
   if (GV1 && GV2 && GV1 != GV2)
-    return NoAlias;
+    return AliasResult::NoAlias;
 
   // If one is based on an indirect global and the other isn't, it isn't
   // strictly safe but we can fake this result if necessary for performance.
   // This does not appear to be a common problem in practice.
   if (EnableUnsafeGlobalsModRefAliasResults)
     if ((GV1 || GV2) && GV1 != GV2)
-      return NoAlias;
+      return AliasResult::NoAlias;
 
   return AAResultBase::alias(LocA, LocB, AAQI);
 }
 
 ModRefInfo GlobalsAAResult::getModRefInfoForArgument(const CallBase *Call,
                                                      const GlobalValue *GV,
                                                      AAQueryInfo &AAQI) {
   if (Call->doesNotAccessMemory())
     return ModRefInfo::NoModRef;
   ModRefInfo ConservativeResult =
       Call->onlyReadsMemory() ? ModRefInfo::Ref : ModRefInfo::ModRef;
 
   // Iterate through all the arguments to the called function. If any argument
   // is based on GV, return the conservative result.
   for (auto &A : Call->args()) {
     SmallVector<const Value*, 4> Objects;
     getUnderlyingObjects(A, Objects);
 
     // All objects must be identified.
     if (!all_of(Objects, isIdentifiedObject) &&
         // Try ::alias to see if all objects are known not to alias GV.
         !all_of(Objects, [&](const Value *V) {
           return this->alias(MemoryLocation::getBeforeOrAfter(V),
                              MemoryLocation::getBeforeOrAfter(GV),
-                             AAQI) == NoAlias;
+                             AAQI) == AliasResult::NoAlias;
         }))
       return ConservativeResult;
 
     if (is_contained(Objects, GV))
       return ConservativeResult;
   }
 
   // We identified all objects in the argument list, and none of them were GV.

llvm/lib/Analysis/Lint.cpp

for (; AI != AE; ++AI) {
             // stack so we're not really passing the pointer anyway.
             if (PAL.hasParamAttribute(ArgNo, Attribute::ByVal))
               continue;
             // If both arguments are readonly, they have no dependence.
             if (Formal->onlyReadsMemory() && I.onlyReadsMemory(ArgNo))
               continue;
             if (AI != BI && (*BI)->getType()->isPointerTy()) {
               AliasResult Result = AA->alias(*AI, *BI);
-              Assert(Result != MustAlias && Result != PartialAlias,
+              Assert(Result != AliasResult::MustAlias &&
+                         Result != AliasResult::PartialAlias,
                      "Unusual: noalias argument aliases another argument", &I);
             }
           }
         }
 
         // Check that an sret argument points to valid memory.
         if (Formal->hasStructRetAttr() && Actual->getType()->isPointerTy()) {
           Type *Ty = Formal->getParamStructRetType();
case Intrinsic::memcpy: {
       // overlap is not distinguished from the case where nothing is known.
       auto Size = LocationSize::afterPointer();
       if (const ConstantInt *Len =
               dyn_cast<ConstantInt>(findValue(MCI->getLength(),
                                               /*OffsetOk=*/false)))
         if (Len->getValue().isIntN(32))
           Size = LocationSize::precise(Len->getValue().getZExtValue());
       Assert(AA->alias(MCI->getSource(), Size, MCI->getDest(), Size) !=
-                 MustAlias,
+                 AliasResult::MustAlias,
              "Undefined behavior: memcpy source and destination overlap", &I);
       break;
     }
     case Intrinsic::memcpy_inline: {
       MemCpyInlineInst *MCII = cast<MemCpyInlineInst>(&I);
       const uint64_t Size = MCII->getLength()->getValue().getLimitedValue();
       visitMemoryReference(I, MemoryLocation::getForDest(MCII),
                            MCII->getDestAlign(), nullptr, MemRef::Write);
       visitMemoryReference(I, MemoryLocation::getForSource(MCII),
                            MCII->getSourceAlign(), nullptr, MemRef::Read);
 
       // Check that the memcpy arguments don't overlap. The AliasAnalysis API
       // isn't expressive enough for what we really want to do. Known partial
       // overlap is not distinguished from the case where nothing is known.
       const LocationSize LS = LocationSize::precise(Size);
-      Assert(AA->alias(MCII->getSource(), LS, MCII->getDest(), LS) != MustAlias,
+      Assert(AA->alias(MCII->getSource(), LS, MCII->getDest(), LS) !=
+                 AliasResult::MustAlias,
              "Undefined behavior: memcpy source and destination overlap", &I);
       break;
     }
     case Intrinsic::memmove: {
       MemMoveInst *MMI = cast<MemMoveInst>(&I);
       visitMemoryReference(I, MemoryLocation::getForDest(MMI),
                            MMI->getDestAlign(), nullptr, MemRef::Write);
       visitMemoryReference(I, MemoryLocation::getForSource(MMI),

llvm/lib/Analysis/MemoryDependenceAnalysis.cpp

if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) {
           return MemDepResult::getDef(II);
         continue;
       }
       case Intrinsic::masked_load:
       case Intrinsic::masked_store: {
         MemoryLocation Loc;
         /*ModRefInfo MR =*/ GetLocation(II, Loc, TLI);
         AliasResult R = BatchAA.alias(Loc, MemLoc);
-        if (R == NoAlias)
+        if (R == AliasResult::NoAlias)
           continue;
-        if (R == MustAlias)
+        if (R == AliasResult::MustAlias)
           return MemDepResult::getDef(II);
         if (ID == Intrinsic::masked_load)
           continue;
         return MemDepResult::getClobber(II);
       }
       }
     }
 
if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
       }
 
       MemoryLocation LoadLoc = MemoryLocation::get(LI);
 
       // If we found a pointer, check if it could be the same as our pointer.
       AliasResult R = BatchAA.alias(LoadLoc, MemLoc);
 
       if (isLoad) {
-        if (R == NoAlias)
+        if (R == AliasResult::NoAlias)
           continue;
 
         // Must aliased loads are defs of each other.
-        if (R == MustAlias)
+        if (R == AliasResult::MustAlias)
           return MemDepResult::getDef(Inst);
 
 #if 0 // FIXME: Temporarily disabled. GVN is cleverly rewriting loads
       // in terms of clobbering loads, but since it does this by looking
       // at the clobbering load directly, it doesn't know about any
       // phi translation that may have happened along the way.
 
         // If we have a partial alias, then return this as a clobber for the
         // client to handle.
-        if (R == PartialAlias)
+        if (R == AliasResult::PartialAlias)
           return MemDepResult::getClobber(Inst);
 #endif
 
         // Random may-alias loads don't depend on each other without a
         // dependence.
         continue;
       }
 
       // Stores don't depend on other no-aliased accesses.
-      if (R == NoAlias)
+      if (R == AliasResult::NoAlias)
         continue;
 
       // Stores don't alias loads from read-only memory.
       if (BatchAA.pointsToConstantMemory(LoadLoc))
         continue;
 
       // Stores depend on may/must aliased loads.
       return MemDepResult::getDef(Inst);
if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
       // Ok, this store might clobber the query pointer.  Check to see if it is
       // a must alias: in this case, we want to return this as a def.
       // FIXME: Use ModRefInfo::Must bit from getModRefInfo call above.
       MemoryLocation StoreLoc = MemoryLocation::get(SI);
 
       // If we found a pointer, check if it could be the same as our pointer.
       AliasResult R = BatchAA.alias(StoreLoc, MemLoc);
 
-      if (R == NoAlias)
+      if (R == AliasResult::NoAlias)
         continue;
-      if (R == MustAlias)
+      if (R == AliasResult::MustAlias)
         return MemDepResult::getDef(Inst);
       if (isInvariantLoad)
         continue;
       return MemDepResult::getClobber(Inst);
     }
 
     // If this is an allocation, and if we know that the accessed pointer is to
     // the allocation, return Def.  This means that there is no dependence and

llvm/lib/Analysis/MemorySSA.cpp

if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(DefInst)) {
     // (including creating MemoryAccesses for them): we just end up inventing
     // clobbers where they don't really exist at all. Please see D43269 for
     // context.
     switch (II->getIntrinsicID()) {
     case Intrinsic::invariant_start:
     case Intrinsic::invariant_end:
     case Intrinsic::assume:
     case Intrinsic::experimental_noalias_scope_decl:
-      return {false, NoAlias};
+      return {false, AliasResult::NoAlias};
     case Intrinsic::dbg_addr:
     case Intrinsic::dbg_declare:
     case Intrinsic::dbg_label:
     case Intrinsic::dbg_value:
       llvm_unreachable("debuginfo shouldn't have associated defs!");
     default:
       break;
     }
   }
 
   if (auto *CB = dyn_cast_or_null<CallBase>(UseInst)) {
     ModRefInfo I = AA.getModRefInfo(DefInst, CB);
-    AR = isMustSet(I) ? MustAlias : MayAlias;
+    AR = isMustSet(I) ? AliasResult::MustAlias : AliasResult::MayAlias;
     return {isModOrRefSet(I), AR};
   }
 
   if (auto *DefLoad = dyn_cast<LoadInst>(DefInst))
     if (auto *UseLoad = dyn_cast_or_null<LoadInst>(UseInst))
-      return {!areLoadsReorderable(UseLoad, DefLoad), MayAlias};
+      return {!areLoadsReorderable(UseLoad, DefLoad), AliasResult::MayAlias};
 
   ModRefInfo I = AA.getModRefInfo(DefInst, UseLoc);
-  AR = isMustSet(I) ? MustAlias : MayAlias;
+  AR = isMustSet(I) ? AliasResult::MustAlias : AliasResult::MayAlias;
   return {isModSet(I), AR};
 }
 
 template <typename AliasAnalysisType>
 static ClobberAlias instructionClobbersQuery(MemoryDef *MD,
                                              const MemoryUseOrDef *MU,
                                              const MemoryLocOrCall &UseMLOC,
                                              AliasAnalysisType &AA) {
struct UpwardsMemoryQuery {
   bool IsCall = false;
   // The pointer location we started the query with. This will be empty if
   // IsCall is true.
   MemoryLocation StartingLoc;
   // This is the instruction we were querying about.
   const Instruction *Inst = nullptr;
   // The MemoryAccess we actually got called with, used to test local domination
   const MemoryAccess *OriginalAccess = nullptr;
-  Optional<AliasResult> AR = MayAlias;
+  Optional<AliasResult> AR = AliasResult::MayAlias;
   bool SkipSelfAccess = false;
 
   UpwardsMemoryQuery() = default;
 
   UpwardsMemoryQuery(const Instruction *Inst, const MemoryAccess *Access)
       : IsCall(isa<CallBase>(Inst)), Inst(Inst), OriginalAccess(Access) {
     if (!IsCall)
       StartingLoc = MemoryLocation::get(Inst);
walkToPhiOrClobber(DefPath &Desc, const MemoryAccess *StopAt = nullptr,
     if (!*UpwardWalkLimit) {
       *UpwardWalkLimit = 1;
       LimitAlreadyReached = true;
     }
 
     for (MemoryAccess *Current : def_chain(Desc.Last)) {
       Desc.Last = Current;
       if (Current == StopAt || Current == SkipStopAt)
-        return {Current, false, MayAlias};
+        return {Current, false, AliasResult::MayAlias};
 
       if (auto *MD = dyn_cast<MemoryDef>(Current)) {
         if (MSSA.isLiveOnEntryDef(MD))
-          return {MD, true, MustAlias};
+          return {MD, true, AliasResult::MustAlias};
 
         if (!--*UpwardWalkLimit)
-          return {Current, true, MayAlias};
+          return {Current, true, AliasResult::MayAlias};
 
         ClobberAlias CA =
             instructionClobbersQuery(MD, Desc.Loc, Query->Inst, AA);
         if (CA.IsClobber)
           return {MD, true, CA.AR};
       }
     }
 
     if (LimitAlreadyReached)
       *UpwardWalkLimit = 0;
 
     assert(isa<MemoryPhi>(Desc.Last) &&
            "Ended at a non-clobber that's not a phi?");
-    return {Desc.Last, false, MayAlias};
+    return {Desc.Last, false, AliasResult::MayAlias};
   }
 
   void addSearches(MemoryPhi *Phi, SmallVectorImpl<ListIndex> &PausedSearches,
                    ListIndex PriorNode) {
     auto UpwardDefsBegin = upward_defs_begin({Phi, Paths[PriorNode].Loc}, DT,
                                              &PerformedPhiTranslation);
     auto UpwardDefs = make_range(UpwardDefsBegin, upward_defs_end());
     for (const MemoryAccessPair &P : UpwardDefs) {
if (LocInfo.PopEpoch != PopEpoch) {
       // new things on the stack, because we've checked everything before.  In
       // this case, the lower bound of things to check remains the same.
       LocInfo.PopEpoch = PopEpoch;
       LocInfo.StackEpoch = StackEpoch;
     }
     if (!LocInfo.LastKillValid) {
       LocInfo.LastKill = VersionStack.size() - 1;
       LocInfo.LastKillValid = true;
-      LocInfo.AR = MayAlias;
+      LocInfo.AR = AliasResult::MayAlias;
     }
 
     // At this point, we should have corrected last kill and LowerBound to be
     // in bounds.
     assert(LocInfo.LowerBound < VersionStack.size() &&
            "Lower bound out of range");
     assert(LocInfo.LastKill < VersionStack.size() &&
            "Last kill info out of range");
if (MSSA->isLiveOnEntryDef(DefiningAccess)) {
       StartingAccess->setOptimizedAccessType(None);
       return DefiningAccess;
     }
 
     OptimizedAccess = Walker.findClobber(DefiningAccess, Q, UpwardWalkLimit);
     StartingAccess->setOptimized(OptimizedAccess);
     if (MSSA->isLiveOnEntryDef(OptimizedAccess))
       StartingAccess->setOptimizedAccessType(None);
-    else if (Q.AR == MustAlias)
-      StartingAccess->setOptimizedAccessType(MustAlias);
+    else if (Q.AR == AliasResult::MustAlias)
+      StartingAccess->setOptimizedAccessType(AliasResult::MustAlias);
   } else
     OptimizedAccess = StartingAccess->getOptimized();
 
   LLVM_DEBUG(dbgs() << "Starting Memory SSA clobber for " << *I << " is ");
   LLVM_DEBUG(dbgs() << *StartingAccess << "\n");
   LLVM_DEBUG(dbgs() << "Optimized Memory SSA clobber for " << *I << " is ");
   LLVM_DEBUG(dbgs() << *OptimizedAccess << "\n");
 

llvm/lib/Analysis/ObjCARCAliasAnalysis.cpp

AliasResult ObjCARCAAResult::alias(const MemoryLocation &LocA,
 
   // First, strip off no-ops, including ObjC-specific no-ops, and try making a
   // precise alias query.
   const Value *SA = GetRCIdentityRoot(LocA.Ptr);
   const Value *SB = GetRCIdentityRoot(LocB.Ptr);
   AliasResult Result =
       AAResultBase::alias(MemoryLocation(SA, LocA.Size, LocA.AATags),
                           MemoryLocation(SB, LocB.Size, LocB.AATags), AAQI);
-  if (Result != MayAlias)
+  if (Result != AliasResult::MayAlias)
     return Result;
 
   // If that failed, climb to the underlying object, including climbing through
   // ObjC-specific no-ops, and try making an imprecise alias query.
   const Value *UA = GetUnderlyingObjCPtr(SA);
   const Value *UB = GetUnderlyingObjCPtr(SB);
   if (UA != SA || UB != SB) {
     Result = AAResultBase::alias(MemoryLocation::getBeforeOrAfter(UA),
                                  MemoryLocation::getBeforeOrAfter(UB), AAQI);
     // We can't use MustAlias or PartialAlias results here because
     // GetUnderlyingObjCPtr may return an offsetted pointer value.
-    if (Result == NoAlias)
-      return NoAlias;
+    if (Result == AliasResult::NoAlias)
+      return AliasResult::NoAlias;
   }
 
   // If that failed, fail. We don't need to chain here, since that's covered
   // by the earlier precise query.
-  return MayAlias;
+  return AliasResult::MayAlias;
 }
 
 bool ObjCARCAAResult::pointsToConstantMemory(const MemoryLocation &Loc,
                                              AAQueryInfo &AAQI, bool OrLocal) {
   if (!EnableARCOpts)
     return AAResultBase::pointsToConstantMemory(Loc, AAQI, OrLocal);
 
   // First, strip off no-ops, including ObjC-specific no-ops, and try making

llvm/lib/Analysis/ScalarEvolutionAliasAnalysis.cpp

 using namespace llvm;
 
 AliasResult SCEVAAResult::alias(const MemoryLocation &LocA,
                                 const MemoryLocation &LocB, AAQueryInfo &AAQI) {
   // If either of the memory references is empty, it doesn't matter what the
   // pointer values are. This allows the code below to ignore this special
   // case.
   if (LocA.Size.isZero() || LocB.Size.isZero())
-    return NoAlias;
+    return AliasResult::NoAlias;
 
   // This is SCEVAAResult. Get the SCEVs!
   const SCEV *AS = SE.getSCEV(const_cast<Value *>(LocA.Ptr));
   const SCEV *BS = SE.getSCEV(const_cast<Value *>(LocB.Ptr));
 
   // If they evaluate to the same expression, it's a MustAlias.
   if (AS == BS)
-    return MustAlias;
+    return AliasResult::MustAlias;
 
   // If something is known about the difference between the two addresses,
   // see if it's enough to prove a NoAlias.
   if (SE.getEffectiveSCEVType(AS->getType()) ==
       SE.getEffectiveSCEVType(BS->getType())) {
     unsigned BitWidth = SE.getTypeSizeInBits(AS->getType());
     APInt ASizeInt(BitWidth, LocA.Size.hasValue()
                                  ? LocA.Size.getValue()
                                  : MemoryLocation::UnknownSize);
     APInt BSizeInt(BitWidth, LocB.Size.hasValue()
                                  ? LocB.Size.getValue()
                                  : MemoryLocation::UnknownSize);
 
     // Compute the difference between the two pointers.
     const SCEV *BA = SE.getMinusSCEV(BS, AS);
 
     // Test whether the difference is known to be great enough that memory of
     // the given sizes don't overlap. This assumes that ASizeInt and BSizeInt
     // are non-zero, which is special-cased above.
     if (ASizeInt.ule(SE.getUnsignedRange(BA).getUnsignedMin()) &&
         (-BSizeInt).uge(SE.getUnsignedRange(BA).getUnsignedMax()))
-      return NoAlias;
+      return AliasResult::NoAlias;
 
     // Folding the subtraction while preserving range information can be tricky
     // (because of INT_MIN, etc.); if the prior test failed, swap AS and BS
     // and try again to see if things fold better that way.
 
     // Compute the difference between the two pointers.
     const SCEV *AB = SE.getMinusSCEV(AS, BS);
 
     // Test whether the difference is known to be great enough that memory of
     // the given sizes don't overlap. This assumes that ASizeInt and BSizeInt
     // are non-zero, which is special-cased above.
     if (BSizeInt.ule(SE.getUnsignedRange(AB).getUnsignedMin()) &&
         (-ASizeInt).uge(SE.getUnsignedRange(AB).getUnsignedMax()))
-      return NoAlias;
+      return AliasResult::NoAlias;
   }
 
   // If ScalarEvolution can find an underlying object, form a new query.
   // The correctness of this depends on ScalarEvolution not recognizing
   // inttoptr and ptrtoint operators.
   Value *AO = GetBaseValue(AS);
   Value *BO = GetBaseValue(BS);
   if ((AO && AO != LocA.Ptr) || (BO && BO != LocB.Ptr))
     if (alias(MemoryLocation(AO ? AO : LocA.Ptr,
                              AO ? LocationSize::beforeOrAfterPointer()
                                 : LocA.Size,
                              AO ? AAMDNodes() : LocA.AATags),
               MemoryLocation(BO ? BO : LocB.Ptr,
                              BO ? LocationSize::beforeOrAfterPointer()
                                 : LocB.Size,
                              BO ? AAMDNodes() : LocB.AATags),
-              AAQI) == NoAlias)
-      return NoAlias;
+              AAQI) == AliasResult::NoAlias)
+      return AliasResult::NoAlias;
 
   // Forward the query to the next analysis.
   return AAResultBase::alias(LocA, LocB, AAQI);
 }
 
 /// Given an expression, try to find a base value.
 ///
 /// Returns null if none was found.

llvm/lib/Analysis/ScopedNoAliasAA.cpp

if (!EnableScopedNoAlias)
     return AAResultBase::alias(LocA, LocB, AAQI);
 
   // Get the attached MDNodes.
   const MDNode *AScopes = LocA.AATags.Scope, *BScopes = LocB.AATags.Scope;
 
   const MDNode *ANoAlias = LocA.AATags.NoAlias, *BNoAlias = LocB.AATags.NoAlias;
 
   if (!mayAliasInScopes(AScopes, BNoAlias))
-    return NoAlias;
+    return AliasResult::NoAlias;
 
   if (!mayAliasInScopes(BScopes, ANoAlias))
-    return NoAlias;
+    return AliasResult::NoAlias;
 
   // If they may alias, chain to the next AliasAnalysis.
   return AAResultBase::alias(LocA, LocB, AAQI);
 }
 
 ModRefInfo ScopedNoAliasAAResult::getModRefInfo(const CallBase *Call,
                                                 const MemoryLocation &Loc,
                                                 AAQueryInfo &AAQI) {

llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp

AliasResult TypeBasedAAResult::alias(const MemoryLocation &LocA,
   if (!EnableTBAA)
     return AAResultBase::alias(LocA, LocB, AAQI);
 
   // If accesses may alias, chain to the next AliasAnalysis.
   if (Aliases(LocA.AATags.TBAA, LocB.AATags.TBAA))
     return AAResultBase::alias(LocA, LocB, AAQI);
 
   // Otherwise return a definitive result.
-  return NoAlias;
+  return AliasResult::NoAlias;
 }
 
 bool TypeBasedAAResult::pointsToConstantMemory(const MemoryLocation &Loc,
                                                AAQueryInfo &AAQI,
                                                bool OrLocal) {
   if (!EnableTBAA)
     return AAResultBase::pointsToConstantMemory(Loc, AAQI, OrLocal);
 

llvm/lib/CodeGen/DFAPacketizer.cpp

bool VLIWPacketizerList::alias(const MachineMemOperand &Op1,
   int64_t Overlapb = Op2.getSize() + Op2.getOffset() - MinOffset;
 
   AliasResult AAResult =
       AA->alias(MemoryLocation(Op1.getValue(), Overlapa,
                                UseTBAA ? Op1.getAAInfo() : AAMDNodes()),
                 MemoryLocation(Op2.getValue(), Overlapb,
                                UseTBAA ? Op2.getAAInfo() : AAMDNodes()));
 
-  return AAResult != NoAlias;
+  return AAResult != AliasResult::NoAlias;
 }
 
 bool VLIWPacketizerList::alias(const MachineInstr &MI1,
                                const MachineInstr &MI2,
                                bool UseTBAA) const {
   if (MI1.memoperands_empty() || MI2.memoperands_empty())
     return true;
 

llvm/lib/CodeGen/ImplicitNullChecks.cpp

for (MachineMemOperand *MMO1 : MI.memoperands()) {
     // as implicit null check.
     assert(MMO1->getValue() && "MMO1 should have a Value!");
     for (MachineMemOperand *MMO2 : PrevMI->memoperands()) {
       if (const PseudoSourceValue *PSV = MMO2->getPseudoValue()) {
         if (PSV->mayAlias(MFI))
           return AR_MayAlias;
         continue;
       }
-      llvm::AliasResult AAResult = AA->alias(
+      if (!AA->isNoAlias(
               MemoryLocation::getAfter(MMO1->getValue(), MMO1->getAAInfo()),
-          MemoryLocation::getAfter(MMO2->getValue(), MMO2->getAAInfo()));
-      if (AAResult != NoAlias)
+              MemoryLocation::getAfter(MMO2->getValue(), MMO2->getAAInfo())))
         return AR_MayAlias;
     }
   }
   return AR_NoAlias;
 }
 
 ImplicitNullChecks::SuitabilityResult
 ImplicitNullChecks::isSuitableMemoryOp(const MachineInstr &MI,

llvm/lib/CodeGen/MachineInstr.cpp

static bool MemOperandsHaveAlias(const MachineFrameInfo &MFI, AAResults *AA,
   assert((OffsetA >= 0) && "Negative MachineMemOperand offset");
   assert((OffsetB >= 0) && "Negative MachineMemOperand offset");
 
   int64_t OverlapA =
       KnownWidthA ? WidthA + OffsetA - MinOffset : MemoryLocation::UnknownSize;
   int64_t OverlapB =
       KnownWidthB ? WidthB + OffsetB - MinOffset : MemoryLocation::UnknownSize;
 
-  AliasResult AAResult = AA->alias(
+  return !AA->isNoAlias(
       MemoryLocation(ValA, OverlapA, UseTBAA ? MMOa->getAAInfo() : AAMDNodes()),
       MemoryLocation(ValB, OverlapB,
                      UseTBAA ? MMOb->getAAInfo() : AAMDNodes()));
-
-  return (AAResult != NoAlias);
 }
 
 bool MachineInstr::mayAlias(AAResults *AA, const MachineInstr &Other,
                             bool UseTBAA) const {
   const MachineFunction *MF = getMF();
   const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
   const MachineFrameInfo &MFI = MF->getFrameInfo();
 

llvm/lib/CodeGen/MachinePipeliner.cpp

else if (MI.mayLoad()) {
           }
           if (MMO1->getValue() == MMO2->getValue() &&
               MMO1->getOffset() <= MMO2->getOffset()) {
             SDep Dep(Load, SDep::Barrier);
             Dep.setLatency(1);
             SU.addPred(Dep);
             continue;
           }
-          AliasResult AAResult = AA->alias(
+          if (!AA->isNoAlias(
                   MemoryLocation::getAfter(MMO1->getValue(), MMO1->getAAInfo()),
-              MemoryLocation::getAfter(MMO2->getValue(), MMO2->getAAInfo()));
-
-          if (AAResult != NoAlias) {
+                  MemoryLocation::getAfter(MMO2->getValue(),
+                                           MMO2->getAAInfo()))) {
             SDep Dep(Load, SDep::Barrier);
             Dep.setLatency(1);
             SU.addPred(Dep);
           }
         }
       }
     }
   }

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

 #endif
 
   if (UseAA && AA && MUC0.MMO->getValue() && MUC1.MMO->getValue() &&
       Size0.hasValue() && Size1.hasValue()) {
     // Use alias analysis information.
     int64_t MinOffset = std::min(SrcValOffset0, SrcValOffset1);
     int64_t Overlap0 = *Size0 + SrcValOffset0 - MinOffset;
     int64_t Overlap1 = *Size1 + SrcValOffset1 - MinOffset;
-    AliasResult AAResult = AA->alias(
+    if (AA->isNoAlias(
             MemoryLocation(MUC0.MMO->getValue(), Overlap0,
                            UseTBAA ? MUC0.MMO->getAAInfo() : AAMDNodes()),
             MemoryLocation(MUC1.MMO->getValue(), Overlap1,
-                       UseTBAA ? MUC1.MMO->getAAInfo() : AAMDNodes()));
-    if (AAResult == NoAlias)
+                           UseTBAA ? MUC1.MMO->getAAInfo() : AAMDNodes())))
       return false;
   }
 
   // Otherwise we have to assume they alias.
   return true;
 }
 
 /// Walk up chain skipping non-aliasing memory nodes,

llvm/lib/Target/AMDGPU/AMDGPUAliasAnalysis.cpp

 
 ImmutablePass *llvm::createAMDGPUExternalAAWrapperPass() {
   return new AMDGPUExternalAAWrapper();
 }
 
 void AMDGPUAAWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
 }
 
-// These arrays are indexed by address space value enum elements 0 ... to 7
-static const AliasResult ASAliasRules[8][8] = {
-  /*                    Flat       Global    Region    Group     Constant  Private   Constant 32-bit  Buffer Fat Ptr */
-  /* Flat     */        {MayAlias, MayAlias, NoAlias,  MayAlias, MayAlias, MayAlias, MayAlias,        MayAlias},
-  /* Global   */        {MayAlias, MayAlias, NoAlias , NoAlias , MayAlias, NoAlias , MayAlias,        MayAlias},
-  /* Region   */        {NoAlias,  NoAlias , MayAlias, NoAlias , NoAlias,  NoAlias , NoAlias,         NoAlias},
-  /* Group    */        {MayAlias, NoAlias , NoAlias , MayAlias, NoAlias , NoAlias , NoAlias ,        NoAlias},
-  /* Constant */        {MayAlias, MayAlias, NoAlias,  NoAlias , NoAlias , NoAlias , MayAlias,        MayAlias},
-  /* Private  */        {MayAlias, NoAlias , NoAlias , NoAlias , NoAlias , MayAlias, NoAlias ,        NoAlias},
-  /* Constant 32-bit */ {MayAlias, MayAlias, NoAlias,  NoAlias , MayAlias, NoAlias , NoAlias ,        MayAlias},
-  /* Buffer Fat Ptr  */ {MayAlias, MayAlias, NoAlias , NoAlias , MayAlias, NoAlias , MayAlias,        MayAlias}
-};
-
 static AliasResult getAliasResult(unsigned AS1, unsigned AS2) {
   static_assert(AMDGPUAS::MAX_AMDGPU_ADDRESS <= 7, "Addr space out of range");
 
   if (AS1 > AMDGPUAS::MAX_AMDGPU_ADDRESS || AS2 > AMDGPUAS::MAX_AMDGPU_ADDRESS)
-    return MayAlias;
+    return AliasResult::MayAlias;
+
+#define ASMay AliasResult::MayAlias
+#define ASNo AliasResult::NoAlias
+  // This array is indexed by address space value enum elements 0 ... to 7
+  static const AliasResult ASAliasRules[8][8] = {
+    /*                    Flat    Global Region Group  Constant Private Const32 Buf Fat Ptr */
+    /* Flat     */        {ASMay, ASMay, ASNo,  ASMay, ASMay,   ASMay,  ASMay,  ASMay},
+    /* Global   */        {ASMay, ASMay, ASNo,  ASNo,  ASMay,   ASNo,   ASMay,  ASMay},
+    /* Region   */        {ASNo,  ASNo,  ASMay, ASNo,  ASNo,    ASNo,   ASNo,   ASNo},
+    /* Group    */        {ASMay, ASNo,  ASNo,  ASMay, ASNo,    ASNo,   ASNo,   ASNo},
+    /* Constant */        {ASMay, ASMay, ASNo,  ASNo,  ASNo,    ASNo,   ASMay,  ASMay},
+    /* Private  */        {ASMay, ASNo,  ASNo,  ASNo,  ASNo,    ASMay,  ASNo,   ASNo},
+    /* Constant 32-bit */ {ASMay, ASMay, ASNo,  ASNo,  ASMay,   ASNo,   ASNo,   ASMay},
+    /* Buffer Fat Ptr  */ {ASMay, ASMay, ASNo,  ASNo,  ASMay,   ASNo,   ASMay,  ASMay}
+  };
+#undef ASMay
+#undef ASNo
 
   return ASAliasRules[AS1][AS2];
 }
 
 AliasResult AMDGPUAAResult::alias(const MemoryLocation &LocA,
                                   const MemoryLocation &LocB,
                                   AAQueryInfo &AAQI) {
   unsigned asA = LocA.Ptr->getType()->getPointerAddressSpace();
   unsigned asB = LocB.Ptr->getType()->getPointerAddressSpace();
 
   AliasResult Result = getAliasResult(asA, asB);
-  if (Result == NoAlias)
+  if (Result == AliasResult::NoAlias)
     return Result;
 
   // In general, FLAT (generic) pointers could be aliased to LOCAL or PRIVATE
   // pointers. However, as LOCAL or PRIVATE pointers point to local objects, in
   // certain cases, it's still viable to check whether a FLAT pointer won't
   // alias to a LOCAL or PRIVATE pointer.
   MemoryLocation A = LocA;
   MemoryLocation B = LocB;
   // Canonicalize the location order to simplify the following alias check.
   if (asA != AMDGPUAS::FLAT_ADDRESS) {
     std::swap(asA, asB);
     std::swap(A, B);
   }
   if (asA == AMDGPUAS::FLAT_ADDRESS &&
       (asB == AMDGPUAS::LOCAL_ADDRESS || asB == AMDGPUAS::PRIVATE_ADDRESS)) {
     const auto *ObjA =
         getUnderlyingObject(A.Ptr->stripPointerCastsForAliasAnalysis());
     if (const LoadInst *LI = dyn_cast<LoadInst>(ObjA)) {
       // If a generic pointer is loaded from the constant address space, it
       // could only be a GLOBAL or CONSTANT one as that address space is soley
       // prepared on the host side, where only GLOBAL or CONSTANT variables are
       // visible. Note that this even holds for regular functions.
       if (LI->getPointerAddressSpace() == AMDGPUAS::CONSTANT_ADDRESS)
-        return NoAlias;
+        return AliasResult::NoAlias;
     } else if (const Argument *Arg = dyn_cast<Argument>(ObjA)) {
       const Function *F = Arg->getParent();
       switch (F->getCallingConv()) {
       case CallingConv::AMDGPU_KERNEL:
         // In the kernel function, kernel arguments won't alias to (local)
         // variables in shared or private address space.
-        return NoAlias;
+        return AliasResult::NoAlias;
       default:
         // TODO: In the regular function, if that local variable in the
         // location B is not captured, that argument pointer won't alias to it
         // as well.
         break;
       }
     }
   }

llvm/lib/Target/Hexagon/HexagonStoreWidening.cpp

bool HexagonStoreWidening::instrAliased(InstrGroup &Stores,
   MemoryLocation L(MMO.getValue(), MMO.getSize(), MMO.getAAInfo());
 
   for (auto SI : Stores) {
     const MachineMemOperand &SMO = getStoreTarget(SI);
     if (!SMO.getValue())
       return true;
 
     MemoryLocation SL(SMO.getValue(), SMO.getSize(), SMO.getAAInfo());
-    if (AA->alias(L, SL))
+    if (!AA->isNoAlias(L, SL))
       return true;
   }
 
   return false;
 }
 
 // Check if the machine instruction MI accesses any storage aliased with
 // any store in the group Stores.

llvm/lib/Target/SystemZ/SystemZISelDAGToDAG.cpp

bool SystemZDAGToDAGISel::canUseBlockOperation(StoreSDNode *Store,
 
   // Reject equality.
   uint64_t Size = Load->getMemoryVT().getStoreSize();
   int64_t End1 = Load->getSrcValueOffset() + Size;
   int64_t End2 = Store->getSrcValueOffset() + Size;
   if (V1 == V2 && End1 == End2)
     return false;
 
-  return !AA->alias(MemoryLocation(V1, End1, Load->getAAInfo()),
+  return AA->isNoAlias(MemoryLocation(V1, End1, Load->getAAInfo()),
                        MemoryLocation(V2, End2, Store->getAAInfo()));
 }
 
 bool SystemZDAGToDAGISel::storeLoadCanUseMVC(SDNode *N) const {
   auto *Store = cast<StoreSDNode>(N);
   auto *Load = cast<LoadSDNode>(Store->getValue());
 
   // Prefer not to use MVC if either address can use ... RELATIVE LONG
   // instructions.

llvm/lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp

bool X86AvoidSFBPass::alias(const MachineMemOperand &Op1,
                             const MachineMemOperand &Op2) const {
   if (!Op1.getValue() || !Op2.getValue())
     return true;
 
   int64_t MinOffset = std::min(Op1.getOffset(), Op2.getOffset());
   int64_t Overlapa = Op1.getSize() + Op1.getOffset() - MinOffset;
   int64_t Overlapb = Op2.getSize() + Op2.getOffset() - MinOffset;
 
-  AliasResult AAResult =
-      AA->alias(MemoryLocation(Op1.getValue(), Overlapa, Op1.getAAInfo()),
-                MemoryLocation(Op2.getValue(), Overlapb, Op2.getAAInfo()));
-  return AAResult != NoAlias;
+  return !AA->isNoAlias(
+      MemoryLocation(Op1.getValue(), Overlapa, Op1.getAAInfo()),
 }
 
 void X86AvoidSFBPass::findPotentiallylBlockedCopies(MachineFunction &MF) {
   for (auto &MBB : MF)
     for (auto &MI : MBB) {
       if (!isPotentialBlockedMemCpyLd(MI.getOpcode()))
         continue;
       int DefVR = MI.getOperand(0).getReg();

llvm/lib/Transforms/Coroutines/CoroElide.cpp

static void replaceWithConstant(Constant *Value,
   // Now the value type matches the type of the intrinsic. Replace them all!
   for (CoroSubFnInst *I : Users)
     replaceAndRecursivelySimplify(I, Value);
 }
 
 // See if any operand of the call instruction references the coroutine frame.
 static bool operandReferences(CallInst *CI, AllocaInst *Frame, AAResults &AA) {
   for (Value *Op : CI->operand_values())
-    if (AA.alias(Op, Frame) != NoAlias)
+    if (!AA.isNoAlias(Op, Frame))
       return true;
   return false;
 }
 
 // Look for any tail calls referencing the coroutine frame and remove tail
 // attribute from them, since now coroutine frame resides on the stack and tail
 // call implies that the function does not references anything on the stack.
 // However if it's a musttail call, we cannot remove the tailcall attribute.

llvm/lib/Transforms/ObjCARC/ObjCARCOpts.cpp

for (BasicBlock::iterator B = CurrentBB->begin(),
       case ARCInstKind::LoadWeakRetained: {
         // If this is loading from the same pointer, replace this load's value
         // with that one.
         CallInst *Call = cast<CallInst>(Inst);
         CallInst *EarlierCall = cast<CallInst>(EarlierInst);
         Value *Arg = Call->getArgOperand(0);
         Value *EarlierArg = EarlierCall->getArgOperand(0);
         switch (PA.getAA()->alias(Arg, EarlierArg)) {
-        case MustAlias:
+        case AliasResult::MustAlias:
           Changed = true;
           // If the load has a builtin retain, insert a plain retain for it.
           if (Class == ARCInstKind::LoadWeakRetained) {
             Function *Decl = EP.get(ARCRuntimeEntryPointKind::Retain);
             CallInst *CI = CallInst::Create(Decl, EarlierCall, "", Call);
             CI->setTailCall();
           }
           // Zap the fully redundant load.
           Call->replaceAllUsesWith(EarlierCall);
           Call->eraseFromParent();
           goto clobbered;
-        case MayAlias:
-        case PartialAlias:
+        case AliasResult::MayAlias:
+        case AliasResult::PartialAlias:
           goto clobbered;
-        case NoAlias:
+        case AliasResult::NoAlias:
           break;
         }
         break;
       }
       case ARCInstKind::StoreWeak:
       case ARCInstKind::InitWeak: {
         // If this is storing to the same pointer and has the same size etc.
         // replace this load's value with the stored value.
         CallInst *Call = cast<CallInst>(Inst);
         CallInst *EarlierCall = cast<CallInst>(EarlierInst);
         Value *Arg = Call->getArgOperand(0);
         Value *EarlierArg = EarlierCall->getArgOperand(0);
         switch (PA.getAA()->alias(Arg, EarlierArg)) {
-        case MustAlias:
+        case AliasResult::MustAlias:
           Changed = true;
           // If the load has a builtin retain, insert a plain retain for it.
           if (Class == ARCInstKind::LoadWeakRetained) {
             Function *Decl = EP.get(ARCRuntimeEntryPointKind::Retain);
             CallInst *CI = CallInst::Create(Decl, EarlierCall, "", Call);
             CI->setTailCall();
           }
           // Zap the fully redundant load.
           Call->replaceAllUsesWith(EarlierCall->getArgOperand(1));
           Call->eraseFromParent();
           goto clobbered;
-        case MayAlias:
-        case PartialAlias:
+        case AliasResult::MayAlias:
+        case AliasResult::PartialAlias:
           goto clobbered;
-        case NoAlias:
+        case AliasResult::NoAlias:
           break;
         }
         break;
       }
       case ARCInstKind::MoveWeak:
       case ARCInstKind::CopyWeak:
         // TOOD: Grab the copied value.
         goto clobbered;

llvm/lib/Transforms/ObjCARC/ProvenanceAnalysis.cpp

static bool IsStoredObjCPointer(const Value *P) {
 
   // Everything checked out.
   return false;
 }
 
 bool ProvenanceAnalysis::relatedCheck(const Value *A, const Value *B) {
   // Ask regular AliasAnalysis, for a first approximation.
   switch (AA->alias(A, B)) {
-  case NoAlias:
+  case AliasResult::NoAlias:
     return false;
-  case MustAlias:
-  case PartialAlias:
+  case AliasResult::MustAlias:
+  case AliasResult::PartialAlias:
     return true;
-  case MayAlias:
+  case AliasResult::MayAlias:
     break;
   }
 
   bool AIsIdentified = IsObjCIdentifiedObject(A);
   bool BIsIdentified = IsObjCIdentifiedObject(B);
 
   // An ObjC-Identified object can't alias a load if it is never locally stored.
   if (AIsIdentified) {

llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp

public:
   /// Ensure that the memory in \p Load does not alias \p Store by potentially
   /// copying it to a new location.  This new or otherwise the original location
   /// is returned.
   Value *getNonAliasingPointer(LoadInst *Load, StoreInst *Store,
                                CallInst *MatMul) {
     MemoryLocation StoreLoc = MemoryLocation::get(Store);
     MemoryLocation LoadLoc = MemoryLocation::get(Load);
 
-    AliasResult LdAliased = AA->alias(LoadLoc, StoreLoc);
-
     // If we can statically determine noalias we're good.
-    if (!LdAliased)
+    if (AA->isNoAlias(LoadLoc, StoreLoc))
       return Load->getPointerOperand();
 
     // Create code to check if the memory locations of the Load and Store
     // overlap and if they do, copy Load's operand to a new buffer.
 
     // First, create  new blocks for 2n part of the check and the copy.
     BasicBlock *Check0 = MatMul->getParent();
     // FIXME: Use lazy DTU and update SplitBlock to accept a DTU instead of a

llvm/lib/Transforms/Utils/FlattenCFG.cpp

while (true) {
     // avoided if read from memory doesn't exist.
     if (iter1->mayReadFromMemory())
       return false;
 
     if (iter1->mayWriteToMemory()) {
       for (BasicBlock::iterator BI(PBI2), BE(PTI2); BI != BE; ++BI) {
         if (BI->mayReadFromMemory() || BI->mayWriteToMemory()) {
           // Check alias with Head2.
-          if (!AA || AA->alias(&*iter1, &*BI))
+          if (!AA || !AA->isNoAlias(&*iter1, &*BI))
             return false;
         }
       }
     }
     ++iter1;
     ++iter2;
   }
 

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

bool isAliased(const MemoryLocation &Loc1, Instruction *Inst1,
     Optional<bool> &result = AliasCache[key];
     if (result.hasValue()) {
       return result.getValue();
     }
     MemoryLocation Loc2 = getLocation(Inst2, AA);
     bool aliased = true;
     if (Loc1.Ptr && Loc2.Ptr && isSimple(Inst1) && isSimple(Inst2)) {
       // Do the alias check.
-      aliased = AA->alias(Loc1, Loc2);
+      aliased = !AA->isNoAlias(Loc1, Loc2);
     }
     // Store the result in the cache.
     result = aliased;
     return aliased;
   }
 
   using AliasCacheKey = std::pair<Instruction *, Instruction *>;
 

llvm/unittests/Analysis/AliasAnalysisTest.cpp

struct TestCustomAAResult : AAResultBase<TestCustomAAResult> {
   TestCustomAAResult(TestCustomAAResult &&Arg)
       : AAResultBase(std::move(Arg)), CB(std::move(Arg.CB)) {}
 
   bool invalidate(Function &, const PreservedAnalyses &) { return false; }
 
   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB,
                     AAQueryInfo &AAQI) {
     CB();
-    return MayAlias;
+    return AliasResult::MayAlias;
   }
 };
 }
 
 namespace {
 /// A wrapper pass for the legacy pass manager to use with the above custom AA
 /// result.
 class TestCustomAAWrapperPass : public ImmutablePass {
TEST_F(AliasAnalysisTest, BatchAAPhiCycles) {
   Instruction *S2 = getInstructionByName(*F, "s2");
   MemoryLocation PhiLoc(Phi, LocationSize::precise(1));
   MemoryLocation A1Loc(A1, LocationSize::precise(1));
   MemoryLocation A2Loc(A2, LocationSize::precise(1));
   MemoryLocation S1Loc(S1, LocationSize::precise(1));
   MemoryLocation S2Loc(S2, LocationSize::precise(1));
 
   auto &AA = getAAResults(*F);
-  EXPECT_EQ(NoAlias, AA.alias(A1Loc, A2Loc));
-  EXPECT_EQ(MayAlias, AA.alias(PhiLoc, A1Loc));
-  EXPECT_EQ(MayAlias, AA.alias(S1Loc, S2Loc));
+  EXPECT_EQ(AliasResult::NoAlias, AA.alias(A1Loc, A2Loc));
+  EXPECT_EQ(AliasResult::MayAlias, AA.alias(PhiLoc, A1Loc));
+  EXPECT_EQ(AliasResult::MayAlias, AA.alias(S1Loc, S2Loc));
 
   BatchAAResults BatchAA(AA);
-  EXPECT_EQ(NoAlias, BatchAA.alias(A1Loc, A2Loc));
-  EXPECT_EQ(MayAlias, BatchAA.alias(PhiLoc, A1Loc));
-  EXPECT_EQ(MayAlias, BatchAA.alias(S1Loc, S2Loc));
+  EXPECT_EQ(AliasResult::NoAlias, BatchAA.alias(A1Loc, A2Loc));
+  EXPECT_EQ(AliasResult::MayAlias, BatchAA.alias(PhiLoc, A1Loc));
+  EXPECT_EQ(AliasResult::MayAlias, BatchAA.alias(S1Loc, S2Loc));
 
   BatchAAResults BatchAA2(AA);
-  EXPECT_EQ(NoAlias, BatchAA2.alias(A1Loc, A2Loc));
-  EXPECT_EQ(MayAlias, BatchAA2.alias(S1Loc, S2Loc));
-  EXPECT_EQ(MayAlias, BatchAA2.alias(PhiLoc, A1Loc));
+  EXPECT_EQ(AliasResult::NoAlias, BatchAA2.alias(A1Loc, A2Loc));
+  EXPECT_EQ(AliasResult::MayAlias, BatchAA2.alias(S1Loc, S2Loc));
+  EXPECT_EQ(AliasResult::MayAlias, BatchAA2.alias(PhiLoc, A1Loc));
 }
 
 TEST_F(AliasAnalysisTest, BatchAAPhiAssumption) {
   LLVMContext C;
   SMDiagnostic Err;
   std::unique_ptr<Module> M = parseAssemblyString(R"(
     define void @f(i8* %a.base, i8* %b.base, i1 %c) {
     entry:
TEST_F(AliasAnalysisTest, BatchAAPhiAssumption) {
   Instruction *ANext = getInstructionByName(*F, "a.next");
   Instruction *BNext = getInstructionByName(*F, "b.next");
   MemoryLocation ALoc(A, LocationSize::precise(1));
   MemoryLocation BLoc(B, LocationSize::precise(1));
   MemoryLocation ANextLoc(ANext, LocationSize::precise(1));
   MemoryLocation BNextLoc(BNext, LocationSize::precise(1));
 
   auto &AA = getAAResults(*F);
-  EXPECT_EQ(MayAlias, AA.alias(ALoc, BLoc));
-  EXPECT_EQ(MayAlias, AA.alias(ANextLoc, BNextLoc));
+  EXPECT_EQ(AliasResult::MayAlias, AA.alias(ALoc, BLoc));
+  EXPECT_EQ(AliasResult::MayAlias, AA.alias(ANextLoc, BNextLoc));
 
   BatchAAResults BatchAA(AA);
-  EXPECT_EQ(MayAlias, BatchAA.alias(ALoc, BLoc));
-  EXPECT_EQ(MayAlias, BatchAA.alias(ANextLoc, BNextLoc));
+  EXPECT_EQ(AliasResult::MayAlias, BatchAA.alias(ALoc, BLoc));
+  EXPECT_EQ(AliasResult::MayAlias, BatchAA.alias(ANextLoc, BNextLoc));
 }
 
 // Check that two aliased GEPs with non-constant offsets are correctly
 // analyzed and their relative offset can be requested from AA.
 TEST_F(AliasAnalysisTest, PartialAliasOffset) {
   LLVMContext C;
   SMDiagnostic Err;
   std::unique_ptr<Module> M = parseAssemblyString(R"(
TEST_F(AliasAnalysisTest, PartialAliasOffset) {
 
   Function *F = M->getFunction("foo");
   const auto Loc1 = MemoryLocation::get(getInstructionByName(*F, "L1"));
   auto Loc2 = MemoryLocation::get(getInstructionByName(*F, "L2"));
 
   auto &AA = getAAResults(*F);
 
   BatchAAResults BatchAA(AA, /*CacheOffsets =*/true);
-  EXPECT_EQ(PartialAlias, BatchAA.alias(Loc1, Loc2));
+  EXPECT_EQ(AliasResult::PartialAlias, BatchAA.alias(Loc1, Loc2));
   EXPECT_EQ(-4, BatchAA.getClobberOffset(Loc1, Loc2).getValueOr(0));
   EXPECT_EQ(4, BatchAA.getClobberOffset(Loc2, Loc1).getValueOr(0));
 
   // Check that no offset returned for different size.
   Loc2.Size = LocationSize::precise(42);
   EXPECT_EQ(0, BatchAA.getClobberOffset(Loc1, Loc2).getValueOr(0));
 }
 

llvm/unittests/Analysis/MemorySSATest.cpp

for (LoadInst *V : {LA1, LA2}) {
     EXPECT_EQ(MemUse->getOptimizedAccessType(), None)
         << "Load " << I << " doesn't have the correct alias information";
     // EXPECT_EQ expands such that if we increment I above, it won't get
     // incremented except when we try to print the error message.
     ++I;
   }
   for (LoadInst *V : {LA3, LA4}) {
     MemoryUse *MemUse = dyn_cast_or_null<MemoryUse>(MSSA.getMemoryAccess(V));
-    EXPECT_EQ(MemUse->getOptimizedAccessType(), MustAlias)
+    EXPECT_EQ(MemUse->getOptimizedAccessType(), AliasResult::MustAlias)
         << "Load " << I << " doesn't have the correct alias information";
     // EXPECT_EQ expands such that if we increment I above, it won't get
     // incremented except when we try to print the error message.
     ++I;
   }
 }
 
 // Test Must alias for optimized defs.
else {
                            << " has Defining Access equal to Clobbering Access";
     }
     EXPECT_EQ(MemDef->isOptimized(), true)
         << "Store " << I << " was not optimized";
     if (I == 0 || I == 1)
       EXPECT_EQ(MemDef->getOptimizedAccessType(), None)
           << "Store " << I << " doesn't have the correct alias information";
     else
-      EXPECT_EQ(MemDef->getOptimizedAccessType(), MustAlias)
+      EXPECT_EQ(MemDef->getOptimizedAccessType(), AliasResult::MustAlias)
           << "Store " << I << " doesn't have the correct alias information";
     // EXPECT_EQ expands such that if we increment I above, it won't get
     // incremented except when we try to print the error message.
     ++I;
   }
 }
 
 // Test May alias for optimized uses.
TEST_F(MemorySSATest, TestLoadMayAlias) {
   LoadInst *LB2 = B.CreateLoad(Int8, PointerB, "");
 
   setupAnalyses();
   MemorySSA &MSSA = *Analyses->MSSA;
 
   unsigned I = 0;
   for (LoadInst *V : {LA1, LB1}) {
     MemoryUse *MemUse = dyn_cast_or_null<MemoryUse>(MSSA.getMemoryAccess(V));
-    EXPECT_EQ(MemUse->getOptimizedAccessType(), MayAlias)
+    EXPECT_EQ(MemUse->getOptimizedAccessType(), AliasResult::MayAlias)
         << "Load " << I << " doesn't have the correct alias information";
     // EXPECT_EQ expands such that if we increment I above, it won't get
     // incremented except when we try to print the error message.
     ++I;
   }
   for (LoadInst *V : {LA2, LB2}) {
     MemoryUse *MemUse = dyn_cast_or_null<MemoryUse>(MSSA.getMemoryAccess(V));
-    EXPECT_EQ(MemUse->getOptimizedAccessType(), MustAlias)
+    EXPECT_EQ(MemUse->getOptimizedAccessType(), AliasResult::MustAlias)
         << "Load " << I << " doesn't have the correct alias information";
     // EXPECT_EQ expands such that if we increment I above, it won't get
     // incremented except when we try to print the error message.
     ++I;
   }
 }
 
 // Test May alias for optimized defs.
for (StoreInst *V : Sts)
     Walker->getClobberingMemoryAccess(V);
 
   I = 0;
   for (StoreInst *V : Sts) {
     MemoryDef *MemDef = dyn_cast_or_null<MemoryDef>(MSSA.getMemoryAccess(V));
     EXPECT_EQ(MemDef->isOptimized(), true)
         << "Store " << I << " was not optimized";
     if (I == 1 || I == 3 || I == 4)
-      EXPECT_EQ(MemDef->getOptimizedAccessType(), MayAlias)
+      EXPECT_EQ(MemDef->getOptimizedAccessType(), AliasResult::MayAlias)
           << "Store " << I << " doesn't have the correct alias information";
     else if (I == 0 || I == 2)
       EXPECT_EQ(MemDef->getOptimizedAccessType(), None)
           << "Store " << I << " doesn't have the correct alias information";
     else
-      EXPECT_EQ(MemDef->getOptimizedAccessType(), MustAlias)
+      EXPECT_EQ(MemDef->getOptimizedAccessType(), AliasResult::MustAlias)
           << "Store " << I << " doesn't have the correct alias information";
     // EXPECT_EQ expands such that if we increment I above, it won't get
     // incremented except when we try to print the error message.
     ++I;
   }
 }
 
 TEST_F(MemorySSATest, LifetimeMarkersAreClobbers) {
if (BB.getName() == "exit") {
           upward_defs_begin({ItA->first, ItA->second}, MSSA.getDomTree());
       // Check if the location information have been retained
       EXPECT_TRUE(ItB->second.Size.isPrecise());
       EXPECT_TRUE(ItB->second.Size.hasValue());
       EXPECT_TRUE(ItB->second.Size.getValue() == 8);
     }
   }
 }
 No newline at end of file