[PM/AA] Completely remove the AliasAnalysis::copyValue interface.

No in-tree alias analysis used this facility, and it was not called in
any particularly rigorous way, so it seems unlikely to be correct.

Note that one of the only stateful AA implementations in-tree,
GlobalsModRef is completely broken currently (and any AA passes like it
are equally broken) because Module AA passes are not effectively
invalidated when a function pass that fails to update the AA stack runs.

Ultimately, it doesn't seem like we know how we want to build stateful
AA, and until then trying to support and maintain correctness for an
untested API is essentially impossible. To that end, I'm planning to rip
out all of the update API. It can return if and when we need it and know
how to build it on top of the new pass manager and as part of *tested*
stateful AA implementations in the tree.

Differential Revision: http://reviews.llvm.org/D10889

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241975 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/AliasAnalysis.h

@@ -518,14 +518,6 @@ class AliasAnalysis {
   ///
   virtual void deleteValue(Value *V);
 
-  /// copyValue - This method should be used whenever a preexisting value in the
-  /// program is copied or cloned, introducing a new value.  Note that analysis
-  /// implementations should tolerate clients that use this method to introduce
-  /// the same value multiple times: if the analysis already knows about a
-  /// value, it should ignore the request.
-  ///
-  virtual void copyValue(Value *From, Value *To);
-
   /// addEscapingUse - This method should be used whenever an escaping use is
   /// added to a pointer value.  Analysis implementations may either return
   /// conservative responses for that value in the future, or may recompute
@@ -541,7 +533,6 @@ class AliasAnalysis {
   /// above, and it provided as a helper to simplify client code.
   ///
   void replaceWithNewValue(Value *Old, Value *New) {
-    copyValue(Old, New);
     deleteValue(Old);
   }
 };

lib/Analysis/AliasAnalysis.cpp

@@ -71,11 +71,6 @@ void AliasAnalysis::deleteValue(Value *V) {
   AA->deleteValue(V);
 }
 
-void AliasAnalysis::copyValue(Value *From, Value *To) {
-  assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!");
-  AA->copyValue(From, To);
-}
-
 void AliasAnalysis::addEscapingUse(Use &U) {
   assert(AA && "AA didn't call InitializeAliasAnalysis in its run method!");
   AA->addEscapingUse(U);

lib/Analysis/AliasDebugger.cpp

@@ -124,10 +124,6 @@ namespace {
       assert(Vals.find(V) != Vals.end() && "Never seen value in AA before");
       AliasAnalysis::deleteValue(V);
     }
-    void copyValue(Value *From, Value *To) override {
-      Vals.insert(To);
-      AliasAnalysis::copyValue(From, To);
-    }
 
   };
 }

lib/Analysis/AliasSetTracker.cpp

@@ -544,9 +544,6 @@ void AliasSetTracker::deleteValue(Value *PtrVal) {
 // the tracker already knows about a value, it will ignore the request.
 //
 void AliasSetTracker::copyValue(Value *From, Value *To) {
-  // Notify the alias analysis implementation that this value is copied.
-  AA.copyValue(From, To);
-
   // First, look up the PointerRec for this pointer.
   PointerMapType::iterator I = PointerMap.find_as(From);
   if (I == PointerMap.end())

lib/Analysis/IPA/GlobalsModRef.cpp

@@ -158,7 +158,6 @@ namespace {
     }
 
     void deleteValue(Value *V) override;
-    void copyValue(Value *From, Value *To) override;
     void addEscapingUse(Use &U) override;
 
     /// getAdjustedAnalysisPointer - This method is used when a pass implements
@@ -585,10 +584,6 @@ void GlobalsModRef::deleteValue(Value *V) {
   AliasAnalysis::deleteValue(V);
 }
 
-void GlobalsModRef::copyValue(Value *From, Value *To) {
-  AliasAnalysis::copyValue(From, To);
-}
-
 void GlobalsModRef::addEscapingUse(Use &U) {
   // For the purposes of this analysis, it is conservatively correct to treat
   // a newly escaping value equivalently to a deleted one.  We could perhaps

lib/Analysis/NoAliasAnalysis.cpp

@@ -72,7 +72,6 @@ namespace {
     }
 
     void deleteValue(Value *V) override {}
-    void copyValue(Value *From, Value *To) override {}
     void addEscapingUse(Use &U) override {}
 
     /// getAdjustedAnalysisPointer - This method is used when a pass implements

lib/Transforms/IPO/ArgumentPromotion.cpp

@@ -825,7 +825,6 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
             V = GetElementPtrInst::Create(SI->first, V, Ops,
                                           V->getName() + ".idx", Call);
             Ops.clear();
-            AA.copyValue(OrigLoad->getOperand(0), V);
           }
           // Since we're replacing a load make sure we take the alignment
           // of the previous load.
@@ -837,7 +836,6 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
           newLoad->setAAMetadata(AAInfo);
 
           Args.push_back(newLoad);
-          AA.copyValue(OrigLoad, Args.back());
         }
       }
 

lib/Transforms/Scalar/GVN.cpp

@@ -1304,11 +1304,7 @@ static Value *ConstructSSAForLoadSet(LoadInst *LI,
   if (V->getType()->getScalarType()->isPointerTy()) {
     AliasAnalysis *AA = gvn.getAliasAnalysis();
 
-    for (unsigned i = 0, e = NewPHIs.size(); i != e; ++i)
-      AA->copyValue(LI, NewPHIs[i]);
-
-    // Now that we've copied information to the new PHIs, scan through
-    // them again and inform alias analysis that we've added potentially
+    // Scan the new PHIs and inform alias analysis that we've added potentially
     // escaping uses to any values that are operands to these PHIs.
     for (unsigned i = 0, e = NewPHIs.size(); i != e; ++i) {
       PHINode *P = NewPHIs[i];

lib/Transforms/Scalar/MergedLoadStoreMotion.cpp

@@ -301,10 +301,6 @@ void MergedLoadStoreMotion::hoistInstruction(BasicBlock *BB,
   // Merged instruction
   Instruction *HoistedInst = HoistCand->clone();
 
-  // Notify AA of the new value.
-  if (isa<LoadInst>(HoistCand))
-    AA->copyValue(HoistCand, HoistedInst);
-
   // Hoist instruction.
   HoistedInst->insertBefore(HoistPt);
 
@@ -451,9 +447,6 @@ PHINode *MergedLoadStoreMotion::getPHIOperand(BasicBlock *BB, StoreInst *S0,
     NewPN->addIncoming(Opd1, S0->getParent());
     NewPN->addIncoming(Opd2, S1->getParent());
     if (NewPN->getType()->getScalarType()->isPointerTy()) {
-      // Notify AA of the new value.
-      AA->copyValue(Opd1, NewPN);
-      AA->copyValue(Opd2, NewPN);
       // AA needs to be informed when a PHI-use of the pointer value is added
       for (unsigned I = 0, E = NewPN->getNumIncomingValues(); I != E; ++I) {
         unsigned J = PHINode::getOperandNumForIncomingValue(I);
@@ -491,7 +484,6 @@ bool MergedLoadStoreMotion::sinkStore(BasicBlock *BB, StoreInst *S0,
     // Create the new store to be inserted at the join point.
     StoreInst *SNew = (StoreInst *)(S0->clone());
     Instruction *ANew = A0->clone();
-    AA->copyValue(S0, SNew);
     SNew->insertBefore(InsertPt);
     ANew->insertBefore(SNew);
 

lib/Transforms/Utils/BasicBlockUtils.cpp

@@ -440,8 +440,6 @@ static void UpdatePHINodes(BasicBlock *OrigBB, BasicBlock *NewBB,
     // Create the new PHI node, insert it into NewBB at the end of the block
     PHINode *NewPHI =
         PHINode::Create(PN->getType(), Preds.size(), PN->getName() + ".ph", BI);
-    if (AA)
-      AA->copyValue(PN, NewPHI);
 
     // NOTE! This loop walks backwards for a reason! First off, this minimizes
     // the cost of removal if we end up removing a large number of values, and

lib/Transforms/Utils/LoopSimplify.cpp

@@ -403,7 +403,6 @@ static BasicBlock *insertUniqueBackedgeBlock(Loop *L, BasicBlock *Preheader,
     PHINode *PN = cast<PHINode>(I);
     PHINode *NewPN = PHINode::Create(PN->getType(), BackedgeBlocks.size(),
                                      PN->getName()+".be", BETerminator);
-    if (AA) AA->copyValue(PN, NewPN);
 
     // Loop over the PHI node, moving all entries except the one for the
     // preheader over to the new PHI node.