X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FTypeBasedAliasAnalysis.cpp;h=27b469a43b01f4998a19c15d7e4ffe434671bdf2;hb=48e3a273de5a3fee954f650045d6eed6b3591ef7;hp=05daf18aa9a1f8ef81f5f4a5331ce251980f430c;hpb=c37e6c073436be77e90ef640c0e6627200ba19f7;p=oota-llvm.git

diff --git a/lib/Analysis/TypeBasedAliasAnalysis.cpp b/lib/Analysis/TypeBasedAliasAnalysis.cpp
index 05daf18aa9a..27b469a43b0 100644
--- a/lib/Analysis/TypeBasedAliasAnalysis.cpp
+++ b/lib/Analysis/TypeBasedAliasAnalysis.cpp
@@ -144,7 +144,7 @@ namespace {
     const MDNode *Node;
 
   public:
-    TBAANode() : Node(0) {}
+    TBAANode() : Node(nullptr) {}
     explicit TBAANode(const MDNode *N) : Node(N) {}
 
     /// getNode - Get the MDNode for this TBAANode.
@@ -182,7 +182,6 @@ namespace {
     const MDNode *Node;
 
   public:
-    TBAAStructTagNode() : Node(0) {}
     explicit TBAAStructTagNode(const MDNode *N) : Node(N) {}
 
     /// Get the MDNode for this TBAAStructTagNode.
@@ -218,7 +217,7 @@ namespace {
     const MDNode *Node;
 
   public:
-    TBAAStructTypeNode() : Node(0) {}
+    TBAAStructTypeNode() : Node(nullptr) {}
     explicit TBAAStructTypeNode(const MDNode *N) : Node(N) {}
 
     /// Get the MDNode for this TBAAStructTypeNode.
@@ -340,7 +339,8 @@ static bool isStructPathTBAA(const MDNode *MD) {
 bool
 TypeBasedAliasAnalysis::Aliases(const MDNode *A,
                                 const MDNode *B) const {
-  if (isStructPathTBAA(A))
+  // Make sure that both MDNodes are struct-path aware.
+  if (isStructPathTBAA(A) && isStructPathTBAA(B))
     return PathAliases(A, B);
 
   // Keep track of the root node for A and B.
@@ -386,6 +386,10 @@ TypeBasedAliasAnalysis::Aliases(const MDNode *A,
 bool
 TypeBasedAliasAnalysis::PathAliases(const MDNode *A,
                                     const MDNode *B) const {
+  // Verify that both input nodes are struct-path aware.
+  assert(isStructPathTBAA(A) && "MDNode A is not struct-path aware.");
+  assert(isStructPathTBAA(B) && "MDNode B is not struct-path aware.");
+
   // Keep track of the root node for A and B.
   TBAAStructTypeNode RootA, RootB;
   TBAAStructTagNode TagA(A), TagB(B);
@@ -450,9 +454,9 @@ TypeBasedAliasAnalysis::alias(const Location &LocA,
 
   // Get the attached MDNodes. If either value lacks a tbaa MDNode, we must
   // be conservative.
-  const MDNode *AM = LocA.TBAATag;
+  const MDNode *AM = LocA.AATags.TBAA;
   if (!AM) return AliasAnalysis::alias(LocA, LocB);
-  const MDNode *BM = LocB.TBAATag;
+  const MDNode *BM = LocB.AATags.TBAA;
   if (!BM) return AliasAnalysis::alias(LocA, LocB);
 
   // If they may alias, chain to the next AliasAnalysis.
@@ -468,7 +472,7 @@ bool TypeBasedAliasAnalysis::pointsToConstantMemory(const Location &Loc,
   if (!EnableTBAA)
     return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
 
-  const MDNode *M = Loc.TBAATag;
+  const MDNode *M = Loc.AATags.TBAA;
   if (!M) return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
 
   // If this is an "immutable" type, we can assume the pointer is pointing
@@ -509,7 +513,7 @@ TypeBasedAliasAnalysis::getModRefInfo(ImmutableCallSite CS,
   if (!EnableTBAA)
     return AliasAnalysis::getModRefInfo(CS, Loc);
 
-  if (const MDNode *L = Loc.TBAATag)
+  if (const MDNode *L = Loc.AATags.TBAA)
     if (const MDNode *M =
           CS.getInstruction()->getMetadata(LLVMContext::MD_tbaa))
       if (!Aliases(L, M))
@@ -555,38 +559,40 @@ bool MDNode::isTBAAVtableAccess() const {
 
 MDNode *MDNode::getMostGenericTBAA(MDNode *A, MDNode *B) {
   if (!A || !B)
-    return NULL;
+    return nullptr;
 
   if (A == B)
     return A;
 
   // For struct-path aware TBAA, we use the access type of the tag.
-  bool StructPath = isStructPathTBAA(A);
+  bool StructPath = isStructPathTBAA(A) && isStructPathTBAA(B);
   if (StructPath) {
     A = cast_or_null<MDNode>(A->getOperand(1));
-    if (!A) return 0;
+    if (!A) return nullptr;
     B = cast_or_null<MDNode>(B->getOperand(1));
-    if (!B) return 0;
+    if (!B) return nullptr;
   }
 
   SmallVector<MDNode *, 4> PathA;
   MDNode *T = A;
   while (T) {
     PathA.push_back(T);
-    T = T->getNumOperands() >= 2 ? cast_or_null<MDNode>(T->getOperand(1)) : 0;
+    T = T->getNumOperands() >= 2 ? cast_or_null<MDNode>(T->getOperand(1))
+                                 : nullptr;
   }
 
   SmallVector<MDNode *, 4> PathB;
   T = B;
   while (T) {
     PathB.push_back(T);
-    T = T->getNumOperands() >= 2 ? cast_or_null<MDNode>(T->getOperand(1)) : 0;
+    T = T->getNumOperands() >= 2 ? cast_or_null<MDNode>(T->getOperand(1))
+                                 : nullptr;
   }
 
   int IA = PathA.size() - 1;
   int IB = PathB.size() - 1;
 
-  MDNode *Ret = 0;
+  MDNode *Ret = nullptr;
   while (IA >= 0 && IB >=0) {
     if (PathA[IA] == PathB[IB])
       Ret = PathA[IA];
@@ -599,9 +605,30 @@ MDNode *MDNode::getMostGenericTBAA(MDNode *A, MDNode *B) {
     return Ret;
 
   if (!Ret)
-    return 0;
+    return nullptr;
   // We need to convert from a type node to a tag node.
   Type *Int64 = IntegerType::get(A->getContext(), 64);
   Value *Ops[3] = { Ret, Ret, ConstantInt::get(Int64, 0) };
   return MDNode::get(A->getContext(), Ops);
 }
+
+void Instruction::getAAMetadata(AAMDNodes &N, bool Merge) const {
+  if (Merge)
+    N.TBAA = MDNode::getMostGenericTBAA(N.TBAA,
+                                        getMetadata(LLVMContext::MD_tbaa));
+  else
+    N.TBAA = getMetadata(LLVMContext::MD_tbaa);
+
+  if (Merge)
+    N.Scope = MDNode::intersect(N.Scope,
+                                getMetadata(LLVMContext::MD_alias_scope));
+  else
+    N.Scope = getMetadata(LLVMContext::MD_alias_scope);
+
+  if (Merge)
+    N.NoAlias = MDNode::intersect(N.NoAlias,
+                                  getMetadata(LLVMContext::MD_noalias));
+  else
+    N.NoAlias = getMetadata(LLVMContext::MD_noalias);
+}
+