X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FVMCore%2FMetadata.cpp;h=91fa1a5931c97f9930b9fc806b4a9c517c83a6aa;hb=e3eddaec4a173c7b9c56aff455d74e4fb2f95daf;hp=8a40fed1ccadc2bc72caa86a696cefbdc2062245;hpb=54630e1cef710e65751e2147cbdd2e018292c435;p=oota-llvm.git

diff --git a/lib/VMCore/Metadata.cpp b/lib/VMCore/Metadata.cpp
index 8a40fed1cca..91fa1a5931c 100644
--- a/lib/VMCore/Metadata.cpp
+++ b/lib/VMCore/Metadata.cpp
@@ -13,13 +13,16 @@
 
 #include "llvm/Metadata.h"
 #include "LLVMContextImpl.h"
-#include "llvm/LLVMContext.h"
-#include "llvm/Module.h"
-#include "llvm/Instruction.h"
+#include "SymbolTableListTraitsImpl.h"
 #include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
-#include "SymbolTableListTraitsImpl.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Instruction.h"
+#include "llvm/LLVMContext.h"
+#include "llvm/Module.h"
+#include "llvm/Support/ConstantRange.h"
+#include "llvm/Support/LeakDetector.h"
 #include "llvm/Support/ValueHandle.h"
 using namespace llvm;
 
@@ -27,25 +30,19 @@ using namespace llvm;
 // MDString implementation.
 //
 
-MDString::MDString(LLVMContext &C, StringRef S)
-  : MetadataBase(Type::getMetadataTy(C), Value::MDStringVal), Str(S) {}
+void MDString::anchor() { }
+
+MDString::MDString(LLVMContext &C)
+  : Value(Type::getMetadataTy(C), Value::MDStringVal) {}
 
 MDString *MDString::get(LLVMContext &Context, StringRef Str) {
   LLVMContextImpl *pImpl = Context.pImpl;
-  StringMapEntry<MDString *> &Entry =
+  StringMapEntry<Value*> &Entry =
     pImpl->MDStringCache.GetOrCreateValue(Str);
-  MDString *&S = Entry.getValue();
-  if (!S) S = new MDString(Context, Entry.getKey());
-  return S;
-}
-
-MDString *MDString::get(LLVMContext &Context, const char *Str) {
-  LLVMContextImpl *pImpl = Context.pImpl;
-  StringMapEntry<MDString *> &Entry =
-    pImpl->MDStringCache.GetOrCreateValue(Str ? StringRef(Str) : StringRef());
-  MDString *&S = Entry.getValue();
-  if (!S) S = new MDString(Context, Entry.getKey());
-  return S;
+  Value *&S = Entry.getValue();
+  if (!S) S = new MDString(Context);
+  S->setValueName(&Entry);
+  return cast<MDString>(S);
 }
 
 //===----------------------------------------------------------------------===//
@@ -55,15 +52,31 @@ MDString *MDString::get(LLVMContext &Context, const char *Str) {
 // Use CallbackVH to hold MDNode operands.
 namespace llvm {
 class MDNodeOperand : public CallbackVH {
-  MDNode *Parent;
+  MDNode *getParent() {
+    MDNodeOperand *Cur = this;
+
+    while (Cur->getValPtrInt() != 1)
+      --Cur;
+
+    assert(Cur->getValPtrInt() == 1 &&
+           "Couldn't find the beginning of the operand list!");
+    return reinterpret_cast<MDNode*>(Cur) - 1;
+  }
+
 public:
-  MDNodeOperand(Value *V, MDNode *P) : CallbackVH(V), Parent(P) {}
+  MDNodeOperand(Value *V) : CallbackVH(V) {}
   ~MDNodeOperand() {}
 
   void set(Value *V) {
-    setValPtr(V);
+    unsigned IsFirst = this->getValPtrInt();
+    this->setValPtr(V);
+    this->setAsFirstOperand(IsFirst);
   }
 
+  /// setAsFirstOperand - Accessor method to mark the operand as the first in
+  /// the list.
+  void setAsFirstOperand(unsigned V) { this->setValPtrInt(V); }
+
   virtual void deleted();
   virtual void allUsesReplacedWith(Value *NV);
 };
@@ -71,15 +84,13 @@ public:
 
 
 void MDNodeOperand::deleted() {
-  Parent->replaceOperand(this, 0);
+  getParent()->replaceOperand(this, 0);
 }
 
 void MDNodeOperand::allUsesReplacedWith(Value *NV) {
-  Parent->replaceOperand(this, NV);
+  getParent()->replaceOperand(this, NV);
 }
 
-
-
 //===----------------------------------------------------------------------===//
 // MDNode implementation.
 //
@@ -87,31 +98,43 @@ void MDNodeOperand::allUsesReplacedWith(Value *NV) {
 /// getOperandPtr - Helper function to get the MDNodeOperand's coallocated on
 /// the end of the MDNode.
 static MDNodeOperand *getOperandPtr(MDNode *N, unsigned Op) {
-  assert(Op < N->getNumOperands() && "Invalid operand number");
-  return reinterpret_cast<MDNodeOperand*>(N+1)+Op;
+  // Use <= instead of < to permit a one-past-the-end address.
+  assert(Op <= N->getNumOperands() && "Invalid operand number");
+  return reinterpret_cast<MDNodeOperand*>(N + 1) + Op;
+}
+
+void MDNode::replaceOperandWith(unsigned i, Value *Val) {
+  MDNodeOperand *Op = getOperandPtr(this, i);
+  replaceOperand(Op, Val);
 }
 
-MDNode::MDNode(LLVMContext &C, Value *const *Vals, unsigned NumVals,
-               bool isFunctionLocal)
-: MetadataBase(Type::getMetadataTy(C), Value::MDNodeVal) {
-  NumOperands = NumVals;
+MDNode::MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal)
+: Value(Type::getMetadataTy(C), Value::MDNodeVal) {
+  NumOperands = Vals.size();
 
   if (isFunctionLocal)
     setValueSubclassData(getSubclassDataFromValue() | FunctionLocalBit);
 
   // Initialize the operand list, which is co-allocated on the end of the node.
+  unsigned i = 0;
   for (MDNodeOperand *Op = getOperandPtr(this, 0), *E = Op+NumOperands;
-       Op != E; ++Op, ++Vals)
-    new (Op) MDNodeOperand(*Vals, this);
-}
+       Op != E; ++Op, ++i) {
+    new (Op) MDNodeOperand(Vals[i]);
 
+    // Mark the first MDNodeOperand as being the first in the list of operands.
+    if (i == 0)
+      Op->setAsFirstOperand(1);
+  }
+}
 
 /// ~MDNode - Destroy MDNode.
 MDNode::~MDNode() {
   assert((getSubclassDataFromValue() & DestroyFlag) != 0 &&
          "Not being destroyed through destroy()?");
-  if (!isNotUniqued()) {
-    LLVMContextImpl *pImpl = getType()->getContext().pImpl;
+  LLVMContextImpl *pImpl = getType()->getContext().pImpl;
+  if (isNotUniqued()) {
+    pImpl->NonUniquedMDNodes.erase(this);
+  } else {
     pImpl->MDNodeSet.RemoveNode(this);
   }
 
@@ -121,32 +144,38 @@ MDNode::~MDNode() {
     Op->~MDNodeOperand();
 }
 
+static const Function *getFunctionForValue(Value *V) {
+  if (!V) return NULL;
+  if (Instruction *I = dyn_cast<Instruction>(V)) {
+    BasicBlock *BB = I->getParent();
+    return BB ? BB->getParent() : 0;
+  }
+  if (Argument *A = dyn_cast<Argument>(V))
+    return A->getParent();
+  if (BasicBlock *BB = dyn_cast<BasicBlock>(V))
+    return BB->getParent();
+  if (MDNode *MD = dyn_cast<MDNode>(V))
+    return MD->getFunction();
+  return NULL;
+}
+
 #ifndef NDEBUG
-static Function *assertLocalFunction(const MDNode *N) {
-  if (!N->isFunctionLocal()) return NULL;
+static const Function *assertLocalFunction(const MDNode *N) {
+  if (!N->isFunctionLocal()) return 0;
 
-  Function *F = NULL;
+  // FIXME: This does not handle cyclic function local metadata.
+  const Function *F = 0, *NewF = 0;
   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
-    Value *V = N->getOperand(i);
-    if (!V) continue;
-    if (Instruction *I = dyn_cast<Instruction>(V)) {
-      if (F) assert(F == I->getParent()->getParent() &&
-                    "inconsistent function-local metadata");
-      else F = I->getParent()->getParent();
-    } else if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) {
-      if (F) assert(F == BB->getParent() &&
-                    "inconsistent function-local metadata");
-      else F = BB->getParent();
-    } else if (Argument *A = dyn_cast<Argument>(V)) {
-      if (F) assert(F == A->getParent() &&
-                    "inconsistent function-local metadata");
-      else F = A->getParent();
-    } else if (MDNode *MD = dyn_cast<MDNode>(V)) {
-      if (Function *NewF = assertLocalFunction(MD)) {
-        if (F) assert(F == NewF && "inconsistent function-local metadata");
-        else F = NewF;
-      }
+    if (Value *V = N->getOperand(i)) {
+      if (MDNode *MD = dyn_cast<MDNode>(V))
+        NewF = assertLocalFunction(MD);
+      else
+        NewF = getFunctionForValue(V);
     }
+    if (F == 0)
+      F = NewF;
+    else 
+      assert((NewF == 0 || F == NewF) &&"inconsistent function-local metadata");
   }
   return F;
 }
@@ -154,85 +183,122 @@ static Function *assertLocalFunction(const MDNode *N) {
 
 // getFunction - If this metadata is function-local and recursively has a
 // function-local operand, return the first such operand's parent function.
-// Otherwise, return null. 
-Function *MDNode::getFunction() const {
+// Otherwise, return null. getFunction() should not be used for performance-
+// critical code because it recursively visits all the MDNode's operands.  
+const Function *MDNode::getFunction() const {
 #ifndef NDEBUG
   return assertLocalFunction(this);
-#endif
-
+#else
   if (!isFunctionLocal()) return NULL;
-
-  for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
-    Value *V = getOperand(i);
-    if (!V) continue;
-    if (Instruction *I = dyn_cast<Instruction>(V))
-      return I->getParent()->getParent();
-    if (BasicBlock *BB = dyn_cast<BasicBlock>(V))
-      return BB->getParent();
-    if (Argument *A = dyn_cast<Argument>(V))
-      return A->getParent();
-    if (MDNode *MD = dyn_cast<MDNode>(V))
-      if (Function *F = MD->getFunction()) return F;
-  }
+  for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
+    if (const Function *F = getFunctionForValue(getOperand(i)))
+      return F;
   return NULL;
+#endif
 }
 
 // destroy - Delete this node.  Only when there are no uses.
 void MDNode::destroy() {
   setValueSubclassData(getSubclassDataFromValue() | DestroyFlag);
-  // Placement delete, the free the memory.
+  // Placement delete, then free the memory.
   this->~MDNode();
   free(this);
 }
 
-MDNode *MDNode::getMDNode(LLVMContext &Context, Value *const *Vals,
-                          unsigned NumVals, FunctionLocalness FL) {
+/// isFunctionLocalValue - Return true if this is a value that would require a
+/// function-local MDNode.
+static bool isFunctionLocalValue(Value *V) {
+  return isa<Instruction>(V) || isa<Argument>(V) || isa<BasicBlock>(V) ||
+         (isa<MDNode>(V) && cast<MDNode>(V)->isFunctionLocal());
+}
+
+MDNode *MDNode::getMDNode(LLVMContext &Context, ArrayRef<Value*> Vals,
+                          FunctionLocalness FL, bool Insert) {
   LLVMContextImpl *pImpl = Context.pImpl;
+
+  // Add all the operand pointers. Note that we don't have to add the
+  // isFunctionLocal bit because that's implied by the operands.
+  // Note that if the operands are later nulled out, the node will be
+  // removed from the uniquing map.
   FoldingSetNodeID ID;
-  for (unsigned i = 0; i != NumVals; ++i)
+  for (unsigned i = 0; i != Vals.size(); ++i)
     ID.AddPointer(Vals[i]);
 
   void *InsertPoint;
   MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
-  if (!N) {
-    bool isFunctionLocal = false;
-    switch (FL) {
-    case FL_Unknown:
-      for (unsigned i = 0; i != NumVals; ++i) {
-        Value *V = Vals[i];
-        if (!V) continue;
-        if (isa<Instruction>(V) || isa<Argument>(V) || isa<BasicBlock>(V) ||
-            (isa<MDNode>(V) && cast<MDNode>(V)->isFunctionLocal())) {
-          isFunctionLocal = true;
-          break;
-        }
+
+  if (N || !Insert)
+    return N;
+
+  bool isFunctionLocal = false;
+  switch (FL) {
+  case FL_Unknown:
+    for (unsigned i = 0; i != Vals.size(); ++i) {
+      Value *V = Vals[i];
+      if (!V) continue;
+      if (isFunctionLocalValue(V)) {
+        isFunctionLocal = true;
+        break;
       }
-      break;
-    case FL_No:
-      isFunctionLocal = false;
-      break;
-    case FL_Yes:
-      isFunctionLocal = true;
-      break;
     }
+    break;
+  case FL_No:
+    isFunctionLocal = false;
+    break;
+  case FL_Yes:
+    isFunctionLocal = true;
+    break;
+  }
 
-    // Coallocate space for the node and Operands together, then placement new.
-    void *Ptr = malloc(sizeof(MDNode)+NumVals*sizeof(MDNodeOperand));
-    N = new (Ptr) MDNode(Context, Vals, NumVals, isFunctionLocal);
+  // Coallocate space for the node and Operands together, then placement new.
+  void *Ptr = malloc(sizeof(MDNode) + Vals.size() * sizeof(MDNodeOperand));
+  N = new (Ptr) MDNode(Context, Vals, isFunctionLocal);
+
+  // Cache the operand hash.
+  N->Hash = ID.ComputeHash();
+
+  // InsertPoint will have been set by the FindNodeOrInsertPos call.
+  pImpl->MDNodeSet.InsertNode(N, InsertPoint);
 
-    // InsertPoint will have been set by the FindNodeOrInsertPos call.
-    pImpl->MDNodeSet.InsertNode(N, InsertPoint);
-  }
   return N;
 }
 
-MDNode *MDNode::get(LLVMContext &Context, Value*const* Vals, unsigned NumVals) {
-  return getMDNode(Context, Vals, NumVals, FL_Unknown);
+MDNode *MDNode::get(LLVMContext &Context, ArrayRef<Value*> Vals) {
+  return getMDNode(Context, Vals, FL_Unknown);
+}
+
+MDNode *MDNode::getWhenValsUnresolved(LLVMContext &Context,
+                                      ArrayRef<Value*> Vals,
+                                      bool isFunctionLocal) {
+  return getMDNode(Context, Vals, isFunctionLocal ? FL_Yes : FL_No);
+}
+
+MDNode *MDNode::getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals) {
+  return getMDNode(Context, Vals, FL_Unknown, false);
 }
 
-MDNode *MDNode::getWhenValsUnresolved(LLVMContext &Context, Value*const* Vals,
-                                      unsigned NumVals, bool isFunctionLocal) {
-  return getMDNode(Context, Vals, NumVals, isFunctionLocal ? FL_Yes : FL_No);
+MDNode *MDNode::getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals) {
+  MDNode *N =
+    (MDNode *)malloc(sizeof(MDNode) + Vals.size() * sizeof(MDNodeOperand));
+  N = new (N) MDNode(Context, Vals, FL_No);
+  N->setValueSubclassData(N->getSubclassDataFromValue() |
+                          NotUniquedBit);
+  LeakDetector::addGarbageObject(N);
+  return N;
+}
+
+void MDNode::deleteTemporary(MDNode *N) {
+  assert(N->use_empty() && "Temporary MDNode has uses!");
+  assert(!N->getContext().pImpl->MDNodeSet.RemoveNode(N) &&
+         "Deleting a non-temporary uniqued node!");
+  assert(!N->getContext().pImpl->NonUniquedMDNodes.erase(N) &&
+         "Deleting a non-temporary non-uniqued node!");
+  assert((N->getSubclassDataFromValue() & NotUniquedBit) &&
+         "Temporary MDNode does not have NotUniquedBit set!");
+  assert((N->getSubclassDataFromValue() & DestroyFlag) == 0 &&
+         "Temporary MDNode has DestroyFlag set!");
+  LeakDetector::removeGarbageObject(N);
+  N->destroy();
 }
 
 /// getOperand - Return specified operand.
@@ -241,15 +307,42 @@ Value *MDNode::getOperand(unsigned i) const {
 }
 
 void MDNode::Profile(FoldingSetNodeID &ID) const {
+  // Add all the operand pointers. Note that we don't have to add the
+  // isFunctionLocal bit because that's implied by the operands.
+  // Note that if the operands are later nulled out, the node will be
+  // removed from the uniquing map.
   for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
     ID.AddPointer(getOperand(i));
 }
 
+void MDNode::setIsNotUniqued() {
+  setValueSubclassData(getSubclassDataFromValue() | NotUniquedBit);
+  LLVMContextImpl *pImpl = getType()->getContext().pImpl;
+  pImpl->NonUniquedMDNodes.insert(this);
+}
 
 // Replace value from this node's operand list.
 void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) {
   Value *From = *Op;
 
+  // If is possible that someone did GV->RAUW(inst), replacing a global variable
+  // with an instruction or some other function-local object.  If this is a
+  // non-function-local MDNode, it can't point to a function-local object.
+  // Handle this case by implicitly dropping the MDNode reference to null.
+  // Likewise if the MDNode is function-local but for a different function.
+  if (To && isFunctionLocalValue(To)) {
+    if (!isFunctionLocal())
+      To = 0;
+    else {
+      const Function *F = getFunction();
+      const Function *FV = getFunctionForValue(To);
+      // Metadata can be function-local without having an associated function.
+      // So only consider functions to have changed if non-null.
+      if (F && FV && F != FV)
+        To = 0;
+    }
+  }
+  
   if (From == To)
     return;
 
@@ -268,7 +361,8 @@ void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) {
 
   // If we are dropping an argument to null, we choose to not unique the MDNode
   // anymore.  This commonly occurs during destruction, and uniquing these
-  // brings little reuse.
+  // brings little reuse.  Also, this means we don't need to include
+  // isFunctionLocal bits in FoldingSetNodeIDs for MDNodes.
   if (To == 0) {
     setIsNotUniqued();
     return;
@@ -276,74 +370,198 @@ void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) {
 
   // Now that the node is out of the folding set, get ready to reinsert it.
   // First, check to see if another node with the same operands already exists
-  // in the set.  If it doesn't exist, this returns the position to insert it.
+  // in the set.  If so, then this node is redundant.
   FoldingSetNodeID ID;
   Profile(ID);
   void *InsertPoint;
-  MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
-
-  if (N) {
-    N->replaceAllUsesWith(this);
-    N->destroy();
-    N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
-    assert(N == 0 && "shouldn't be in the map now!"); (void)N;
+  if (MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint)) {
+    replaceAllUsesWith(N);
+    destroy();
+    return;
   }
 
+  // Cache the operand hash.
+  Hash = ID.ComputeHash();
   // InsertPoint will have been set by the FindNodeOrInsertPos call.
   pImpl->MDNodeSet.InsertNode(this, InsertPoint);
+
+  // If this MDValue was previously function-local but no longer is, clear
+  // its function-local flag.
+  if (isFunctionLocal() && !isFunctionLocalValue(To)) {
+    bool isStillFunctionLocal = false;
+    for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+      Value *V = getOperand(i);
+      if (!V) continue;
+      if (isFunctionLocalValue(V)) {
+        isStillFunctionLocal = true;
+        break;
+      }
+    }
+    if (!isStillFunctionLocal)
+      setValueSubclassData(getSubclassDataFromValue() & ~FunctionLocalBit);
+  }
 }
 
-//===----------------------------------------------------------------------===//
-// NamedMDNode implementation.
-//
+MDNode *MDNode::getMostGenericTBAA(MDNode *A, MDNode *B) {
+  if (!A || !B)
+    return NULL;
 
-namespace llvm {
-// SymbolTableListTraits specialization for MDSymbolTable.
-void ilist_traits<NamedMDNode>
-::addNodeToList(NamedMDNode *N) {
-  assert(N->getParent() == 0 && "Value already in a container!!");
-  Module *Owner = getListOwner();
-  N->setParent(Owner);
-  MDSymbolTable &ST = Owner->getMDSymbolTable();
-  ST.insert(N->getName(), N);
+  if (A == B)
+    return A;
+
+  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;
+  }
+
+  SmallVector<MDNode *, 4> PathB;
+  T = B;
+  while (T) {
+    PathB.push_back(T);
+    T = T->getNumOperands() >= 2 ? cast_or_null<MDNode>(T->getOperand(1)) : 0;
+  }
+
+  int IA = PathA.size() - 1;
+  int IB = PathB.size() - 1;
+
+  MDNode *Ret = 0;
+  while (IA >= 0 && IB >=0) {
+    if (PathA[IA] == PathB[IB])
+      Ret = PathA[IA];
+    else
+      break;
+    --IA;
+    --IB;
+  }
+  return Ret;
 }
 
-void ilist_traits<NamedMDNode>::removeNodeFromList(NamedMDNode *N) {
-  N->setParent(0);
-  Module *Owner = getListOwner();
-  MDSymbolTable &ST = Owner->getMDSymbolTable();
-  ST.remove(N->getName());
+MDNode *MDNode::getMostGenericFPMath(MDNode *A, MDNode *B) {
+  if (!A || !B)
+    return NULL;
+
+  APFloat AVal = cast<ConstantFP>(A->getOperand(0))->getValueAPF();
+  APFloat BVal = cast<ConstantFP>(B->getOperand(0))->getValueAPF();
+  if (AVal.compare(BVal) == APFloat::cmpLessThan)
+    return A;
+  return B;
 }
+
+static bool isContiguous(const ConstantRange &A, const ConstantRange &B) {
+  return A.getUpper() == B.getLower() || A.getLower() == B.getUpper();
 }
 
-static SmallVector<WeakVH, 4> &getNMDOps(void *Operands) {
-  return *(SmallVector<WeakVH, 4>*)Operands;
+static bool canBeMerged(const ConstantRange &A, const ConstantRange &B) {
+  return !A.intersectWith(B).isEmptySet() || isContiguous(A, B);
+}
+
+static bool tryMergeRange(SmallVector<Value*, 4> &EndPoints, ConstantInt *Low,
+                          ConstantInt *High) {
+  ConstantRange NewRange(Low->getValue(), High->getValue());
+  unsigned Size = EndPoints.size();
+  APInt LB = cast<ConstantInt>(EndPoints[Size - 2])->getValue();
+  APInt LE = cast<ConstantInt>(EndPoints[Size - 1])->getValue();
+  ConstantRange LastRange(LB, LE);
+  if (canBeMerged(NewRange, LastRange)) {
+    ConstantRange Union = LastRange.unionWith(NewRange);
+    Type *Ty = High->getType();
+    EndPoints[Size - 2] = ConstantInt::get(Ty, Union.getLower());
+    EndPoints[Size - 1] = ConstantInt::get(Ty, Union.getUpper());
+    return true;
+  }
+  return false;
+}
+
+static void addRange(SmallVector<Value*, 4> &EndPoints, ConstantInt *Low,
+                     ConstantInt *High) {
+  if (!EndPoints.empty())
+    if (tryMergeRange(EndPoints, Low, High))
+      return;
+
+  EndPoints.push_back(Low);
+  EndPoints.push_back(High);
 }
 
-NamedMDNode::NamedMDNode(LLVMContext &C, const Twine &N,
-                         MDNode *const *MDs,
-                         unsigned NumMDs, Module *ParentModule)
-  : Value(Type::getMetadataTy(C), Value::NamedMDNodeVal), Parent(0) {
-  setName(N);
-  Operands = new SmallVector<WeakVH, 4>();
+MDNode *MDNode::getMostGenericRange(MDNode *A, MDNode *B) {
+  // Given two ranges, we want to compute the union of the ranges. This
+  // is slightly complitade by having to combine the intervals and merge
+  // the ones that overlap.
 
-  SmallVector<WeakVH, 4> &Node = getNMDOps(Operands);
-  for (unsigned i = 0; i != NumMDs; ++i)
-    Node.push_back(WeakVH(MDs[i]));
+  if (!A || !B)
+    return NULL;
 
-  if (ParentModule)
-    ParentModule->getNamedMDList().push_back(this);
+  if (A == B)
+    return A;
+
+  // First, walk both lists in older of the lower boundary of each interval.
+  // At each step, try to merge the new interval to the last one we adedd.
+  SmallVector<Value*, 4> EndPoints;
+  int AI = 0;
+  int BI = 0;
+  int AN = A->getNumOperands() / 2;
+  int BN = B->getNumOperands() / 2;
+  while (AI < AN && BI < BN) {
+    ConstantInt *ALow = cast<ConstantInt>(A->getOperand(2 * AI));
+    ConstantInt *BLow = cast<ConstantInt>(B->getOperand(2 * BI));
+
+    if (ALow->getValue().slt(BLow->getValue())) {
+      addRange(EndPoints, ALow, cast<ConstantInt>(A->getOperand(2 * AI + 1)));
+      ++AI;
+    } else {
+      addRange(EndPoints, BLow, cast<ConstantInt>(B->getOperand(2 * BI + 1)));
+      ++BI;
+    }
+  }
+  while (AI < AN) {
+    addRange(EndPoints, cast<ConstantInt>(A->getOperand(2 * AI)),
+             cast<ConstantInt>(A->getOperand(2 * AI + 1)));
+    ++AI;
+  }
+  while (BI < BN) {
+    addRange(EndPoints, cast<ConstantInt>(B->getOperand(2 * BI)),
+             cast<ConstantInt>(B->getOperand(2 * BI + 1)));
+    ++BI;
+  }
+
+  // If we have more than 2 ranges (4 endpoints) we have to try to merge
+  // the last and first ones.
+  unsigned Size = EndPoints.size();
+  if (Size > 4) {
+    ConstantInt *FB = cast<ConstantInt>(EndPoints[0]);
+    ConstantInt *FE = cast<ConstantInt>(EndPoints[1]);
+    if (tryMergeRange(EndPoints, FB, FE)) {
+      for (unsigned i = 0; i < Size - 2; ++i) {
+        EndPoints[i] = EndPoints[i + 2];
+      }
+      EndPoints.resize(Size - 2);
+    }
+  }
+
+  // If in the end we have a single range, it is possible that it is now the
+  // full range. Just drop the metadata in that case.
+  if (EndPoints.size() == 2) {
+    ConstantRange Range(cast<ConstantInt>(EndPoints[0])->getValue(),
+                        cast<ConstantInt>(EndPoints[1])->getValue());
+    if (Range.isFullSet())
+      return NULL;
+  }
+
+  return MDNode::get(A->getContext(), EndPoints);
 }
 
-NamedMDNode *NamedMDNode::Create(const NamedMDNode *NMD, Module *M) {
-  assert(NMD && "Invalid source NamedMDNode!");
-  SmallVector<MDNode *, 4> Elems;
-  Elems.reserve(NMD->getNumOperands());
+//===----------------------------------------------------------------------===//
+// NamedMDNode implementation.
+//
+
+static SmallVector<TrackingVH<MDNode>, 4> &getNMDOps(void *Operands) {
+  return *(SmallVector<TrackingVH<MDNode>, 4>*)Operands;
+}
 
-  for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
-    Elems.push_back(NMD->getOperand(i));
-  return new NamedMDNode(NMD->getContext(), NMD->getName().data(),
-                         Elems.data(), Elems.size(), M);
+NamedMDNode::NamedMDNode(const Twine &N)
+  : Name(N.str()), Parent(0),
+    Operands(new SmallVector<TrackingVH<MDNode>, 4>()) {
 }
 
 NamedMDNode::~NamedMDNode() {
@@ -359,18 +577,20 @@ unsigned NamedMDNode::getNumOperands() const {
 /// getOperand - Return specified operand.
 MDNode *NamedMDNode::getOperand(unsigned i) const {
   assert(i < getNumOperands() && "Invalid Operand number!");
-  return dyn_cast_or_null<MDNode>(getNMDOps(Operands)[i]);
+  return dyn_cast<MDNode>(&*getNMDOps(Operands)[i]);
 }
 
 /// addOperand - Add metadata Operand.
 void NamedMDNode::addOperand(MDNode *M) {
-  getNMDOps(Operands).push_back(WeakVH(M));
+  assert(!M->isFunctionLocal() &&
+         "NamedMDNode operands must not be function-local!");
+  getNMDOps(Operands).push_back(TrackingVH<MDNode>(M));
 }
 
 /// eraseFromParent - Drop all references and remove the node from parent
 /// module.
 void NamedMDNode::eraseFromParent() {
-  getParent()->getNamedMDList().erase(this);
+  getParent()->eraseNamedMetadata(this);
 }
 
 /// dropAllReferences - Remove all uses and clear node vector.
@@ -378,81 +598,21 @@ void NamedMDNode::dropAllReferences() {
   getNMDOps(Operands).clear();
 }
 
-/// setName - Set the name of this named metadata.
-void NamedMDNode::setName(const Twine &NewName) {
-  assert (!NewName.isTriviallyEmpty() && "Invalid named metadata name!");
-
-  SmallString<256> NameData;
-  StringRef NameRef = NewName.toStringRef(NameData);
-
-  // Name isn't changing?
-  if (getName() == NameRef)
-    return;
-
-  Name = NameRef.str();
-  if (Parent)
-    Parent->getMDSymbolTable().insert(NameRef, this);
-}
-
 /// getName - Return a constant reference to this named metadata's name.
 StringRef NamedMDNode::getName() const {
   return StringRef(Name);
 }
 
-//===----------------------------------------------------------------------===//
-// LLVMContext MDKind naming implementation.
-//
-
-#ifndef NDEBUG
-/// isValidName - Return true if Name is a valid custom metadata handler name.
-static bool isValidName(StringRef MDName) {
-  if (MDName.empty())
-    return false;
-
-  if (!isalpha(MDName[0]))
-    return false;
-
-  for (StringRef::iterator I = MDName.begin() + 1, E = MDName.end(); I != E;
-       ++I) {
-    if (!isalnum(*I) && *I != '_' && *I != '-' && *I != '.')
-        return false;
-  }
-  return true;
-}
-#endif
-
-/// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
-unsigned LLVMContext::getMDKindID(StringRef Name) const {
-  assert(isValidName(Name) && "Invalid MDNode name");
-
-  unsigned &Entry = pImpl->CustomMDKindNames[Name];
-
-  // If this is new, assign it its ID.
-  if (Entry == 0) Entry = pImpl->CustomMDKindNames.size();
-  return Entry;
-}
-
-/// getHandlerNames - Populate client supplied smallvector using custome
-/// metadata name and ID.
-void LLVMContext::getMDKindNames(SmallVectorImpl<StringRef> &Names) const {
-  Names.resize(pImpl->CustomMDKindNames.size()+1);
-  Names[0] = "";
-  for (StringMap<unsigned>::const_iterator I = pImpl->CustomMDKindNames.begin(),
-       E = pImpl->CustomMDKindNames.end(); I != E; ++I)
-    // MD Handlers are numbered from 1.
-    Names[I->second] = I->first();
-}
-
 //===----------------------------------------------------------------------===//
 // Instruction Metadata method implementations.
 //
 
-void Instruction::setMetadata(const char *Kind, MDNode *Node) {
+void Instruction::setMetadata(StringRef Kind, MDNode *Node) {
   if (Node == 0 && !hasMetadata()) return;
   setMetadata(getContext().getMDKindID(Kind), Node);
 }
 
-MDNode *Instruction::getMetadataImpl(const char *Kind) const {
+MDNode *Instruction::getMetadataImpl(StringRef Kind) const {
   return getMetadataImpl(getContext().getMDKindID(Kind));
 }
 
@@ -462,12 +622,19 @@ MDNode *Instruction::getMetadataImpl(const char *Kind) const {
 void Instruction::setMetadata(unsigned KindID, MDNode *Node) {
   if (Node == 0 && !hasMetadata()) return;
 
+  // Handle 'dbg' as a special case since it is not stored in the hash table.
+  if (KindID == LLVMContext::MD_dbg) {
+    DbgLoc = DebugLoc::getFromDILocation(Node);
+    return;
+  }
+  
   // Handle the case when we're adding/updating metadata on an instruction.
   if (Node) {
     LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
-    assert(!Info.empty() == hasMetadata() && "HasMetadata bit is wonked");
+    assert(!Info.empty() == hasMetadataHashEntry() &&
+           "HasMetadata bit is wonked");
     if (Info.empty()) {
-      setHasMetadata(true);
+      setHasMetadataHashEntry(true);
     } else {
       // Handle replacement of an existing value.
       for (unsigned i = 0, e = Info.size(); i != e; ++i)
@@ -483,18 +650,21 @@ void Instruction::setMetadata(unsigned KindID, MDNode *Node) {
   }
 
   // Otherwise, we're removing metadata from an instruction.
-  assert(hasMetadata() && getContext().pImpl->MetadataStore.count(this) &&
+  assert((hasMetadataHashEntry() ==
+          getContext().pImpl->MetadataStore.count(this)) &&
          "HasMetadata bit out of date!");
+  if (!hasMetadataHashEntry())
+    return;  // Nothing to remove!
   LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
 
   // Common case is removing the only entry.
   if (Info.size() == 1 && Info[0].first == KindID) {
     getContext().pImpl->MetadataStore.erase(this);
-    setHasMetadata(false);
+    setHasMetadataHashEntry(false);
     return;
   }
 
-  // Handle replacement of an existing value.
+  // Handle removal of an existing value.
   for (unsigned i = 0, e = Info.size(); i != e; ++i)
     if (Info[i].first == KindID) {
       Info[i] = Info.back();
@@ -506,8 +676,14 @@ void Instruction::setMetadata(unsigned KindID, MDNode *Node) {
 }
 
 MDNode *Instruction::getMetadataImpl(unsigned KindID) const {
+  // Handle 'dbg' as a special case since it is not stored in the hash table.
+  if (KindID == LLVMContext::MD_dbg)
+    return DbgLoc.getAsMDNode(getContext());
+  
+  if (!hasMetadataHashEntry()) return 0;
+  
   LLVMContextImpl::MDMapTy &Info = getContext().pImpl->MetadataStore[this];
-  assert(hasMetadata() && !Info.empty() && "Shouldn't have called this");
+  assert(!Info.empty() && "bit out of sync with hash table");
 
   for (LLVMContextImpl::MDMapTy::iterator I = Info.begin(), E = Info.end();
        I != E; ++I)
@@ -517,14 +693,40 @@ MDNode *Instruction::getMetadataImpl(unsigned KindID) const {
 }
 
 void Instruction::getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned,
-                                       MDNode*> > &Result)const {
-  assert(hasMetadata() && getContext().pImpl->MetadataStore.count(this) &&
+                                       MDNode*> > &Result) const {
+  Result.clear();
+  
+  // Handle 'dbg' as a special case since it is not stored in the hash table.
+  if (!DbgLoc.isUnknown()) {
+    Result.push_back(std::make_pair((unsigned)LLVMContext::MD_dbg,
+                                    DbgLoc.getAsMDNode(getContext())));
+    if (!hasMetadataHashEntry()) return;
+  }
+  
+  assert(hasMetadataHashEntry() &&
+         getContext().pImpl->MetadataStore.count(this) &&
          "Shouldn't have called this");
   const LLVMContextImpl::MDMapTy &Info =
     getContext().pImpl->MetadataStore.find(this)->second;
   assert(!Info.empty() && "Shouldn't have called this");
 
+  Result.append(Info.begin(), Info.end());
+
+  // Sort the resulting array so it is stable.
+  if (Result.size() > 1)
+    array_pod_sort(Result.begin(), Result.end());
+}
+
+void Instruction::
+getAllMetadataOtherThanDebugLocImpl(SmallVectorImpl<std::pair<unsigned,
+                                    MDNode*> > &Result) const {
   Result.clear();
+  assert(hasMetadataHashEntry() &&
+         getContext().pImpl->MetadataStore.count(this) &&
+         "Shouldn't have called this");
+  const LLVMContextImpl::MDMapTy &Info =
+    getContext().pImpl->MetadataStore.find(this)->second;
+  assert(!Info.empty() && "Shouldn't have called this");
   Result.append(Info.begin(), Info.end());
 
   // Sort the resulting array so it is stable.
@@ -532,10 +734,11 @@ void Instruction::getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned,
     array_pod_sort(Result.begin(), Result.end());
 }
 
-/// removeAllMetadata - Remove all metadata from this instruction.
-void Instruction::removeAllMetadata() {
-  assert(hasMetadata() && "Caller should check");
+/// clearMetadataHashEntries - Clear all hashtable-based metadata from
+/// this instruction.
+void Instruction::clearMetadataHashEntries() {
+  assert(hasMetadataHashEntry() && "Caller should check");
   getContext().pImpl->MetadataStore.erase(this);
-  setHasMetadata(false);
+  setHasMetadataHashEntry(false);
 }