[AliasSetTracker] Return void for add() functions. NFC.

[mcrosier]

Summary

AFAICT, the return value is not used, so remove some unnecessary cruft.

Chad

[haicheng]

LGTM

include/llvm/Analysis/AliasSetTracker.h

public:
   ///   1. If the instruction doesn't alias any other sets, create a new set.
   ///   2. If the instruction aliases exactly one set, add it to the set
   ///   3. If the instruction aliases multiple sets, merge the sets, and add
   ///      the instruction to the result.
   ///
   /// These methods return true if inserting the instruction resulted in the
   /// addition of a new alias set (i.e., the pointer did not alias anything).
   ///
-  bool add(Value *Ptr, uint64_t Size, const AAMDNodes &AAInfo); // Add a loc.
-  bool add(LoadInst *LI);
-  bool add(StoreInst *SI);
-  bool add(VAArgInst *VAAI);
-  bool add(MemSetInst *MSI);
-  bool add(Instruction *I);       // Dispatch to one of the other add methods...
+  void add(Value *Ptr, uint64_t Size, const AAMDNodes &AAInfo); // Add a loc.
+  void add(LoadInst *LI);
+  void add(StoreInst *SI);
+  void add(VAArgInst *VAAI);
+  void add(MemSetInst *MSI);
+  void add(Instruction *I);       // Dispatch to one of the other add methods...
   void add(BasicBlock &BB);       // Add all instructions in basic block
   void add(const AliasSetTracker &AST); // Add alias relations from another AST
-  bool addUnknown(Instruction *I);
+  void addUnknown(Instruction *I);
 
   void clear();
 
   /// Return the alias sets that are active.
   const ilist<AliasSet> &getAliasSets() const { return AliasSets; }
 
   /// Return the alias set that the specified pointer lives in. If the New
   /// argument is non-null, this method sets the value to true if a new alias
   /// set is created to contain the pointer (because the pointer didn't alias
   /// anything).
   AliasSet &getAliasSetForPointer(Value *P, uint64_t Size,
-                                  const AAMDNodes &AAInfo,
-                                  bool *New = nullptr);
+                                  const AAMDNodes &AAInfo);
 
   /// Return the alias set containing the location specified if one exists,
   /// otherwise return null.
   AliasSet *getAliasSetForPointerIfExists(const Value *P, uint64_t Size,
                                           const AAMDNodes &AAInfo) {
     return mergeAliasSetsForPointer(P, Size, AAInfo);
   }
 
private:
   AliasSet::PointerRec &getEntryFor(Value *V) {
     AliasSet::PointerRec *&Entry = PointerMap[ASTCallbackVH(V, this)];
     if (!Entry)
       Entry = new AliasSet::PointerRec(V);
     return *Entry;
   }
 
   AliasSet &addPointer(Value *P, uint64_t Size, const AAMDNodes &AAInfo,
-                       AliasSet::AccessLattice E, bool &NewSet);
+                       AliasSet::AccessLattice E);
   AliasSet *mergeAliasSetsForPointer(const Value *Ptr, uint64_t Size,
                                      const AAMDNodes &AAInfo);
 
   /// Merge all alias sets into a single set that is considered to alias any
   /// pointer.
   AliasSet &mergeAllAliasSets();
 
   AliasSet *findAliasSetForUnknownInst(Instruction *Inst);

lib/Analysis/AliasSetTracker.cpp

else if (!Cur->Forward)   // Otherwise, we must merge the sets.
       FoundSet->mergeSetIn(*Cur, *this);     // Merge in contents.
   }
   return FoundSet;
 }
 
 /// getAliasSetForPointer - Return the alias set that the specified pointer
 /// lives in.
 AliasSet &AliasSetTracker::getAliasSetForPointer(Value *Pointer, uint64_t Size,
-                                                 const AAMDNodes &AAInfo,
-                                                 bool *New) {
+                                                 const AAMDNodes &AAInfo) {
   AliasSet::PointerRec &Entry = getEntryFor(Pointer);
 
   if (AliasAnyAS) {
     // At this point, the AST is saturated, so we only have one active alias
     // set. That means we already know which alias set we want to return, and
     // just need to add the pointer to that set to keep the data structure
     // consistent.
     // This, of course, means that we will never need a merge here.
AliasSet &AliasSetTracker::getAliasSetForPointer(Value *Pointer, uint64_t Size,
   }
   
   if (AliasSet *AS = mergeAliasSetsForPointer(Pointer, Size, AAInfo)) {
     // Add it to the alias set it aliases.
     AS->addPointer(*this, Entry, Size, AAInfo);
     return *AS;
   }
   
-  if (New) *New = true;
   // Otherwise create a new alias set to hold the loaded pointer.
   AliasSets.push_back(new AliasSet());
   AliasSets.back().addPointer(*this, Entry, Size, AAInfo);
   return AliasSets.back();
 }
 
-bool AliasSetTracker::add(Value *Ptr, uint64_t Size, const AAMDNodes &AAInfo) {
-  bool NewPtr;
-  addPointer(Ptr, Size, AAInfo, AliasSet::NoAccess, NewPtr);
-  return NewPtr;
+void AliasSetTracker::add(Value *Ptr, uint64_t Size, const AAMDNodes &AAInfo) {
+  addPointer(Ptr, Size, AAInfo, AliasSet::NoAccess);
 }
 
-
-bool AliasSetTracker::add(LoadInst *LI) {
+void AliasSetTracker::add(LoadInst *LI) {
   if (isStrongerThanMonotonic(LI->getOrdering())) return addUnknown(LI);
 
   AAMDNodes AAInfo;
   LI->getAAMetadata(AAInfo);
 
   AliasSet::AccessLattice Access = AliasSet::RefAccess;
-  bool NewPtr;
   const DataLayout &DL = LI->getModule()->getDataLayout();
   AliasSet &AS = addPointer(LI->getOperand(0),
-                            DL.getTypeStoreSize(LI->getType()),
-                            AAInfo, Access, NewPtr);
+                            DL.getTypeStoreSize(LI->getType()), AAInfo, Access);
   if (LI->isVolatile()) AS.setVolatile();
-  return NewPtr;
 }
 
-bool AliasSetTracker::add(StoreInst *SI) {
+void AliasSetTracker::add(StoreInst *SI) {
   if (isStrongerThanMonotonic(SI->getOrdering())) return addUnknown(SI);
 
   AAMDNodes AAInfo;
   SI->getAAMetadata(AAInfo);
 
   AliasSet::AccessLattice Access = AliasSet::ModAccess;
-  bool NewPtr;
   const DataLayout &DL = SI->getModule()->getDataLayout();
   Value *Val = SI->getOperand(0);
-  AliasSet &AS = addPointer(SI->getOperand(1),
-                            DL.getTypeStoreSize(Val->getType()),
-                            AAInfo, Access, NewPtr);
+  AliasSet &AS = addPointer(
+      SI->getOperand(1), DL.getTypeStoreSize(Val->getType()), AAInfo, Access);
   if (SI->isVolatile()) AS.setVolatile();
-  return NewPtr;
 }
 
-bool AliasSetTracker::add(VAArgInst *VAAI) {
+void AliasSetTracker::add(VAArgInst *VAAI) {
   AAMDNodes AAInfo;
   VAAI->getAAMetadata(AAInfo);
 
-  bool NewPtr;
   addPointer(VAAI->getOperand(0), MemoryLocation::UnknownSize, AAInfo,
-             AliasSet::ModRefAccess, NewPtr);
-  return NewPtr;
+             AliasSet::ModRefAccess);
 }
 
-bool AliasSetTracker::add(MemSetInst *MSI) {
+void AliasSetTracker::add(MemSetInst *MSI) {
   AAMDNodes AAInfo;
   MSI->getAAMetadata(AAInfo);
 
-  bool NewPtr;
   uint64_t Len;
 
   if (ConstantInt *C = dyn_cast<ConstantInt>(MSI->getLength()))
     Len = C->getZExtValue();
   else
     Len = MemoryLocation::UnknownSize;
 
   AliasSet &AS =
-      addPointer(MSI->getRawDest(), Len, AAInfo, AliasSet::ModAccess, NewPtr);
+      addPointer(MSI->getRawDest(), Len, AAInfo, AliasSet::ModAccess);
   if (MSI->isVolatile())
     AS.setVolatile();
-  return NewPtr;
 }
 
-bool AliasSetTracker::addUnknown(Instruction *Inst) {
-  if (isa<DbgInfoIntrinsic>(Inst)) 
-    return true; // Ignore DbgInfo Intrinsics.
+void AliasSetTracker::addUnknown(Instruction *Inst) {
+  if (isa<DbgInfoIntrinsic>(Inst))
+    return; // Ignore DbgInfo Intrinsics.
   if (!Inst->mayReadOrWriteMemory())
-    return true; // doesn't alias anything
+    return; // doesn't alias anything
 
   AliasSet *AS = findAliasSetForUnknownInst(Inst);
   if (AS) {
     AS->addUnknownInst(Inst, AA);
-    return false;
+    return;
   }
   AliasSets.push_back(new AliasSet());
   AS = &AliasSets.back();
   AS->addUnknownInst(Inst, AA);
-  return true;
 }
 
-bool AliasSetTracker::add(Instruction *I) {
+void AliasSetTracker::add(Instruction *I) {
   // Dispatch to one of the other add methods.
   if (LoadInst *LI = dyn_cast<LoadInst>(I))
     return add(LI);
   if (StoreInst *SI = dyn_cast<StoreInst>(I))
     return add(SI);
   if (VAArgInst *VAAI = dyn_cast<VAArgInst>(I))
     return add(VAAI);
   if (MemSetInst *MSI = dyn_cast<MemSetInst>(I))
     return add(MSI);
   return addUnknown(I);
-  // FIXME: add support of memcpy and memmove. 
+  // FIXME: add support of memcpy and memmove.
 }
 
 void AliasSetTracker::add(BasicBlock &BB) {
   for (auto &I : BB)
     add(&I);
 }
 
 void AliasSetTracker::add(const AliasSetTracker &AST) {
   assert(&AA == &AST.AA &&
          "Merging AliasSetTracker objects with different Alias Analyses!");
 
   // Loop over all of the alias sets in AST, adding the pointers contained
   // therein into the current alias sets.  This can cause alias sets to be
   // merged together in the current AST.
   for (const AliasSet &AS : AST) {
     if (AS.Forward)
       continue; // Ignore forwarding alias sets
 
     // If there are any call sites in the alias set, add them to this AST.
     for (unsigned i = 0, e = AS.UnknownInsts.size(); i != e; ++i)
       add(AS.UnknownInsts[i]);
 
     // Loop over all of the pointers in this alias set.
-    bool X;
     for (AliasSet::iterator ASI = AS.begin(), E = AS.end(); ASI != E; ++ASI) {
-      AliasSet &NewAS = addPointer(ASI.getPointer(), ASI.getSize(),
-                                   ASI.getAAInfo(),
-                                   (AliasSet::AccessLattice)AS.Access, X);
+      AliasSet &NewAS =
+          addPointer(ASI.getPointer(), ASI.getSize(), ASI.getAAInfo(),
+                     (AliasSet::AccessLattice)AS.Access);
       if (AS.isVolatile()) NewAS.setVolatile();
     }
   }
 }
 
 // deleteValue method - This method is used to remove a pointer value from the
 // AliasSetTracker entirely.  It should be used when an instruction is deleted
 // from the program to update the AST.  If you don't use this, you would have
for (auto Cur : ASVector) {
     AliasAnyAS->mergeSetIn(*Cur, *this);
   }
 
   return *AliasAnyAS;
 }
 
 AliasSet &AliasSetTracker::addPointer(Value *P, uint64_t Size,
                                       const AAMDNodes &AAInfo,
-                                      AliasSet::AccessLattice E, bool &NewSet) {
+                                      AliasSet::AccessLattice E) {
 
-  NewSet = false;
-  AliasSet &AS = getAliasSetForPointer(P, Size, AAInfo, &NewSet);
+  AliasSet &AS = getAliasSetForPointer(P, Size, AAInfo);
   AS.Access |= E;
 
   if (!AliasAnyAS && (TotalMayAliasSetSize > SaturationThreshold)) {
     // The AST is now saturated. From here on, we conservatively consider all
     // pointers to alias each-other.
     return mergeAllAliasSets();
   }