diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index 053d960..16808a7 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -117,8 +117,7 @@
 
 void *ExecutionEngineState::RemoveMapping(
   const MutexGuard &, const GlobalValue *ToUnmap) {
-  std::map<MapUpdatingCVH, void *>::iterator I =
-    GlobalAddressMap.find(getVH(ToUnmap));
+  GlobalAddressMapTy::iterator I = GlobalAddressMap.find(ToUnmap);
   void *OldVal;
   if (I == GlobalAddressMap.end())
     OldVal = 0;
@@ -141,7 +140,7 @@
 
   DEBUG(errs() << "JIT: Map \'" << GV->getName() 
         << "\' to [" << Addr << "]\n";);
-  void *&CurVal = EEState.getGlobalAddressMap(locked)[EEState.getVH(GV)];
+  void *&CurVal = EEState.getGlobalAddressMap(locked)[GV];
   assert((CurVal == 0 || Addr == 0) && "GlobalMapping already established!");
   CurVal = Addr;
   
@@ -183,7 +182,7 @@
 void *ExecutionEngine::updateGlobalMapping(const GlobalValue *GV, void *Addr) {
   MutexGuard locked(lock);
 
-  std::map<ExecutionEngineState::MapUpdatingCVH, void *> &Map =
+  ExecutionEngineState::GlobalAddressMapTy &Map =
     EEState.getGlobalAddressMap(locked);
 
   // Deleting from the mapping?
@@ -191,7 +190,7 @@
     return EEState.RemoveMapping(locked, GV);
   }
   
-  void *&CurVal = Map[EEState.getVH(GV)];
+  void *&CurVal = Map[GV];
   void *OldVal = CurVal;
 
   if (CurVal && !EEState.getGlobalAddressReverseMap(locked).empty())
@@ -214,8 +213,8 @@
 void *ExecutionEngine::getPointerToGlobalIfAvailable(const GlobalValue *GV) {
   MutexGuard locked(lock);
   
-  std::map<ExecutionEngineState::MapUpdatingCVH, void*>::iterator I =
-    EEState.getGlobalAddressMap(locked).find(EEState.getVH(GV));
+  ExecutionEngineState::GlobalAddressMapTy::iterator I =
+    EEState.getGlobalAddressMap(locked).find(GV);
   return I != EEState.getGlobalAddressMap(locked).end() ? I->second : 0;
 }
 
@@ -227,7 +226,7 @@
 
   // If we haven't computed the reverse mapping yet, do so first.
   if (EEState.getGlobalAddressReverseMap(locked).empty()) {
-    for (std::map<ExecutionEngineState::MapUpdatingCVH, void *>::iterator
+    for (ExecutionEngineState::GlobalAddressMapTy::iterator
          I = EEState.getGlobalAddressMap(locked).begin(),
          E = EEState.getGlobalAddressMap(locked).end(); I != E; ++I)
       EEState.getGlobalAddressReverseMap(locked).insert(std::make_pair(I->second,
@@ -476,7 +475,7 @@
     return getPointerToFunction(F);
 
   MutexGuard locked(lock);
-  void *p = EEState.getGlobalAddressMap(locked)[EEState.getVH(GV)];
+  void *p = EEState.getGlobalAddressMap(locked)[GV];
   if (p)
     return p;
 
@@ -486,7 +485,7 @@
     EmitGlobalVariable(GVar);
   else
     llvm_unreachable("Global hasn't had an address allocated yet!");
-  return EEState.getGlobalAddressMap(locked)[EEState.getVH(GV)];
+  return EEState.getGlobalAddressMap(locked)[GV];
 }
 
 /// This function converts a Constant* into a GenericValue. The interesting 
@@ -1072,17 +1071,22 @@
   ++NumGlobals;
 }
 
-ExecutionEngineState::MapUpdatingCVH::MapUpdatingCVH(
-  ExecutionEngineState &EES, const GlobalValue *GV)
-  : CallbackVH(const_cast<GlobalValue*>(GV)), EES(EES) {}
-
-void ExecutionEngineState::MapUpdatingCVH::deleted() {
-  MutexGuard locked(EES.EE.lock);
-  EES.RemoveMapping(locked, *this);  // Destroys *this.
+ExecutionEngineState::ExecutionEngineState(ExecutionEngine &EE)
+  : EE(EE), GlobalAddressMap(this) {
 }
 
-void ExecutionEngineState::MapUpdatingCVH::allUsesReplacedWith(
-  Value *new_value) {
+sys::Mutex *ExecutionEngineState::AddressMapConfig::getMutex(
+  ExecutionEngineState *EES) {
+  return &EES->EE.lock;
+}
+void ExecutionEngineState::AddressMapConfig::onDelete(
+  ExecutionEngineState *EES, const GlobalValue *Old) {
+  void *OldVal = EES->GlobalAddressMap.lookup(Old);
+  EES->GlobalAddressReverseMap.erase(OldVal);
+}
+
+void ExecutionEngineState::AddressMapConfig::onRAUW(
+  ExecutionEngineState *, const GlobalValue *, const GlobalValue *) {
   assert(false && "The ExecutionEngine doesn't know how to handle a"
          " RAUW on a value it has a global mapping for.");
 }
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index 073d6fb..2915f49 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -46,6 +46,7 @@
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/ValueMap.h"
 #include <algorithm>
 #ifndef NDEBUG
 #include <iomanip>
@@ -62,12 +63,29 @@
 // JIT lazy compilation code.
 //
 namespace {
+  class JITResolverState;
+
+  template<typename ValueTy>
+  struct NoRAUWValueMapConfig : public ValueMapConfig<ValueTy> {
+    typedef JITResolverState *ExtraData;
+    static void onRAUW(JITResolverState *, Value *Old, Value *New) {
+      assert(false && "The JIT doesn't know how to handle a"
+             " RAUW on a value it has emitted.");
+    }
+  };
+
+  struct CallSiteValueMapConfig : public NoRAUWValueMapConfig<Function*> {
+    typedef JITResolverState *ExtraData;
+    static void onDelete(JITResolverState *JRS, Function *F);
+  };
+
   class JITResolverState {
   public:
-    typedef DenseMap<AssertingVH<Function>, void*> FunctionToStubMapTy;
+    typedef ValueMap<Function*, void*, NoRAUWValueMapConfig<Function*> >
+      FunctionToStubMapTy;
     typedef std::map<void*, AssertingVH<Function> > CallSiteToFunctionMapTy;
-    typedef DenseMap<AssertingVH<Function>, SmallPtrSet<void*, 1> >
-            FunctionToCallSitesMapTy;
+    typedef ValueMap<Function *, SmallPtrSet<void*, 1>,
+                     CallSiteValueMapConfig> FunctionToCallSitesMapTy;
     typedef std::map<AssertingVH<GlobalValue>, void*> GlobalToIndirectSymMapTy;
   private:
     /// FunctionToStubMap - Keep track of the stub created for a particular
@@ -84,6 +102,9 @@
     GlobalToIndirectSymMapTy GlobalToIndirectSymMap;
 
   public:
+    JITResolverState() : FunctionToStubMap(this),
+                         FunctionToCallSitesMap(this) {}
+
     FunctionToStubMapTy& getFunctionToStubMap(const MutexGuard& locked) {
       assert(locked.holds(TheJIT->lock));
       return FunctionToStubMap;
@@ -111,8 +132,10 @@
     void AddCallSite(const MutexGuard &locked, void *CallSite, Function *F) {
       assert(locked.holds(TheJIT->lock));
 
-      assert(CallSiteToFunctionMap.insert(std::make_pair(CallSite, F)).second &&
-             "Pair was already in CallSiteToFunctionMap");
+      bool Inserted = CallSiteToFunctionMap.insert(
+          std::make_pair(CallSite, F)).second;
+      (void)Inserted;
+      assert(Inserted && "Pair was already in CallSiteToFunctionMap");
       FunctionToCallSitesMap[F].insert(CallSite);
     }
 
@@ -142,8 +165,9 @@
       FunctionToCallSitesMapTy::iterator F2C_I = FunctionToCallSitesMap.find(F);
       assert(F2C_I != FunctionToCallSitesMap.end() &&
              "FunctionToCallSitesMap broken");
-      assert(F2C_I->second.erase(Stub) &&
-             "FunctionToCallSitesMap broken");
+      bool Erased = F2C_I->second.erase(Stub);
+      (void)Erased;
+      assert(Erased && "FunctionToCallSitesMap broken");
       if (F2C_I->second.empty())
         FunctionToCallSitesMap.erase(F2C_I);
 
@@ -152,13 +176,17 @@
 
     void EraseAllCallSites(const MutexGuard &locked, Function *F) {
       assert(locked.holds(TheJIT->lock));
+      EraseAllCallSitesPrelocked(F);
+    }
+    void EraseAllCallSitesPrelocked(Function *F) {
       FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
       if (F2C == FunctionToCallSitesMap.end())
         return;
       for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
              E = F2C->second.end(); I != E; ++I) {
-        assert(CallSiteToFunctionMap.erase(*I) == 1 &&
-               "Missing call site->function mapping");
+        bool Erased = CallSiteToFunctionMap.erase(*I);
+        (void)Erased;
+        assert(Erased && "Missing call site->function mapping");
       }
       FunctionToCallSitesMap.erase(F2C);
     }
@@ -245,6 +273,10 @@
 
 JITResolver *JITResolver::TheJITResolver = 0;
 
+void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
+  JRS->EraseAllCallSitesPrelocked(F);
+}
+
 /// getFunctionStubIfAvailable - This returns a pointer to a function stub
 /// if it has already been created.
 void *JITResolver::getFunctionStubIfAvailable(Function *F) {