Revert revision 331. The propagation of monomorphic prototype failure

information does not work.  In certains situations, it will keep
alternating between unrelated monomorphic states instead of going
megamorphic.
Review URL: http://codereview.chromium.org/2959

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@338 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/ic.h

@@ -81,12 +81,8 @@ class IC {
   Code* target() { return GetTargetAtAddress(address()); }
   inline Address address();
 
-  // Compute the state of the current inline cache.  If the current
-  // inline cache is monomorphic, this might change the code cache in
-  // the receiver map and it might return a code object from the code
-  // cache in the receiver map that should be used as the new target.
-  static State ComputeCacheState(Code* target, Object* receiver,
-                                 Object* name, Object** new_target);
+  // Compute the current IC state based on the target stub and the receiver.
+  static State StateFrom(Code* target, Object* receiver);
 
   // Clear the inline cache to initial state.
   static void Clear(Address address);
@@ -165,7 +161,7 @@ class CallIC: public IC {
  public:
   CallIC() : IC(EXTRA_CALL_FRAME) { ASSERT(target()->is_call_stub()); }
 
-  Object* LoadFunction(Handle<Object> object, Handle<String> name);
+  Object* LoadFunction(State state, Handle<Object> object, Handle<String> name);
 
 
   // Code generator routines.
@@ -183,6 +179,7 @@ class CallIC: public IC {
   // Update the inline cache and the global stub cache based on the
   // lookup result.
   void UpdateCaches(LookupResult* lookup,
+                    State state,
                     Handle<Object> object,
                     Handle<String> name);
 
@@ -200,7 +197,7 @@ class LoadIC: public IC {
  public:
   LoadIC() : IC(NO_EXTRA_FRAME) { ASSERT(target()->is_load_stub()); }
 
-  Object* Load(Handle<Object> object, Handle<String> name);
+  Object* Load(State state, Handle<Object> object, Handle<String> name);
 
   // Code generator routines.
   static void GenerateInitialize(MacroAssembler* masm);
@@ -222,6 +219,7 @@ class LoadIC: public IC {
   // Update the inline cache and the global stub cache based on the
   // lookup result.
   void UpdateCaches(LookupResult* lookup,
+                    State state,
                     Handle<Object> object,
                     Handle<String> name);
 
@@ -245,7 +243,7 @@ class KeyedLoadIC: public IC {
  public:
   KeyedLoadIC() : IC(NO_EXTRA_FRAME) { ASSERT(target()->is_keyed_load_stub()); }
 
-  Object* Load(Handle<Object> object, Handle<Object> key);
+  Object* Load(State state, Handle<Object> object, Handle<Object> key);
 
   // Code generator routines.
   static void GenerateMiss(MacroAssembler* masm);
@@ -258,6 +256,7 @@ class KeyedLoadIC: public IC {
 
   // Update the inline cache.
   void UpdateCaches(LookupResult* lookup,
+                    State state,
                     Handle<Object> object,
                     Handle<String> name);
 
@@ -284,7 +283,8 @@ class StoreIC: public IC {
  public:
   StoreIC() : IC(NO_EXTRA_FRAME) { ASSERT(target()->is_store_stub()); }
 
-  Object* Store(Handle<Object> object,
+  Object* Store(State state,
+                Handle<Object> object,
                 Handle<String> name,
                 Handle<Object> value);
 
@@ -299,7 +299,7 @@ class StoreIC: public IC {
   // Update the inline cache and the global stub cache based on the
   // lookup result.
   void UpdateCaches(LookupResult* lookup,
-                    Handle<JSObject> receiver,
+                    State state, Handle<JSObject> receiver,
                     Handle<String> name,
                     Handle<Object> value);
 
@@ -320,7 +320,8 @@ class KeyedStoreIC: public IC {
  public:
   KeyedStoreIC() : IC(NO_EXTRA_FRAME) { }
 
-  Object* Store(Handle<Object> object,
+  Object* Store(State state,
+                Handle<Object> object,
                 Handle<Object> name,
                 Handle<Object> value);
 
@@ -334,6 +335,7 @@ class KeyedStoreIC: public IC {
 
   // Update the inline cache.
   void UpdateCaches(LookupResult* lookup,
+                    State state,
                     Handle<JSObject> receiver,
                     Handle<String> name,
                     Handle<Object> value);

src/objects-inl.h

@@ -2109,20 +2109,6 @@ void Map::ClearCodeCache() {
 }
 
 
-Object* Map::FindInCodeCache(String* name, Code::Flags flags) {
-  int index;
-  return FindIndexInCodeCache(name, flags, &index);
-}
-
-
-void Map::RemoveFromCodeCache(int index) {
-  FixedArray* array = code_cache();
-  ASSERT(array->length() >= index && array->get(index)->IsCode());
-  array->set_undefined(index - 1);  // key
-  array->set_undefined(index);  // code
-}
-
-
 #undef CAST_ACCESSOR
 #undef INT_ACCESSORS
 #undef SMI_ACCESSORS

src/objects.cc

@@ -2410,27 +2410,41 @@ Object* Map::UpdateCodeCache(String* name, Code* code) {
 }
 
 
-Object* Map::FindIndexInCodeCache(String* name, Code::Flags flags, int* index) {
+Object* Map::FindInCodeCache(String* name, Code::Flags flags) {
   FixedArray* cache = code_cache();
   int length = cache->length();
   for (int i = 0; i < length; i += 2) {
     Object* key = cache->get(i);
     if (key->IsUndefined()) {
-      continue;
+      return key;
     }
     if (name->Equals(String::cast(key))) {
       Code* code = Code::cast(cache->get(i + 1));
-      if (code->flags() == flags) {
-        *index = i + 1;
-        return code;
-      }
+      if (code->flags() == flags) return code;
     }
   }
-  *index = -1;
   return Heap::undefined_value();
 }
 
 
+int Map::IndexInCodeCache(Code* code) {
+  FixedArray* array = code_cache();
+  int len = array->length();
+  for (int i = 0; i < len; i += 2) {
+    if (array->get(i + 1) == code) return i + 1;
+  }
+  return -1;
+}
+
+
+void Map::RemoveFromCodeCache(int index) {
+  FixedArray* array = code_cache();
+  ASSERT(array->length() >= index && array->get(index)->IsCode());
+  array->set_undefined(index - 1);  // key
+  array->set_undefined(index);  // code
+}
+
+
 void FixedArray::FixedArrayIterateBody(ObjectVisitor* v) {
   IteratePointers(v, kHeaderSize, kHeaderSize + length() * kPointerSize);
 }

src/objects.h

@@ -2342,14 +2342,14 @@ class Map: public HeapObject {
   Object* UpdateCodeCache(String* name, Code* code);
 
   // Returns the found code or undefined if absent.
-  inline Object* FindInCodeCache(String* name, Code::Flags flags);
+  Object* FindInCodeCache(String* name, Code::Flags flags);
 
-  // Returns the found code or undefined if absent.  Also returns the
-  // index at which the code was found or -1 if absent.
-  Object* FindIndexInCodeCache(String* name, Code::Flags flags, int* index);
+  // Returns the non-negative index of the code object if it is in the
+  // cache and -1 otherwise.
+  int IndexInCodeCache(Code* code);
 
   // Removes a code object from the code cache at the given index.
-  inline void RemoveFromCodeCache(int index);
+  void RemoveFromCodeCache(int index);
 
   // Dispatched behavior.
   void MapIterateBody(ObjectVisitor* v);