Map::Normalize() introduced as single entry point for map normalization and...

Map::Normalize() introduced as single entry point for map normalization and Map::NotifyLeafMapLayoutChange() made private.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/263663002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@21117 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/bootstrapper.cc

@@ -2108,9 +2108,8 @@ void Genesis::InstallJSFunctionResultCaches() {
 
 
 void Genesis::InitializeNormalizedMapCaches() {
-  Handle<FixedArray> array(
-      factory()->NewFixedArray(NormalizedMapCache::kEntries, TENURED));
-  native_context()->set_normalized_map_cache(NormalizedMapCache::cast(*array));
+  native_context()->set_normalized_map_cache(
+      *NormalizedMapCache::New(isolate()));
 }
 
 

src/objects-debug.cc

@@ -1015,7 +1015,7 @@ void NormalizedMapCache::NormalizedMapCacheVerify() {
   FixedArray::cast(this)->FixedArrayVerify();
   if (FLAG_enable_slow_asserts) {
     for (int i = 0; i < length(); i++) {
-      Object* e = get(i);
+      Object* e = FixedArray::get(i);
       if (e->IsMap()) {
         Map::cast(e)->SharedMapVerify();
       } else {

src/objects-inl.h

@@ -850,13 +850,23 @@ bool Object::IsJSFunctionResultCache() {
 
 
 bool Object::IsNormalizedMapCache() {
-  if (!IsFixedArray()) return false;
-  if (FixedArray::cast(this)->length() != NormalizedMapCache::kEntries) {
+  return NormalizedMapCache::IsNormalizedMapCache(this);
+}
+
+
+int NormalizedMapCache::GetIndex(Handle<Map> map) {
+  return map->Hash() % NormalizedMapCache::kEntries;
+}
+
+
+bool NormalizedMapCache::IsNormalizedMapCache(Object* obj) {
+  if (!obj->IsFixedArray()) return false;
+  if (FixedArray::cast(obj)->length() != NormalizedMapCache::kEntries) {
     return false;
   }
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) {
-    reinterpret_cast<NormalizedMapCache*>(this)->NormalizedMapCacheVerify();
+    reinterpret_cast<NormalizedMapCache*>(obj)->NormalizedMapCacheVerify();
   }
 #endif
   return true;

src/objects.cc

@@ -4659,48 +4659,30 @@ PropertyAttributes JSObject::GetElementAttributeWithoutInterceptor(
 }
 
 
-Handle<Map> NormalizedMapCache::Get(Handle<NormalizedMapCache> cache,
-                                    Handle<Map> fast_map,
-                                    PropertyNormalizationMode mode) {
-  int index = fast_map->Hash() % kEntries;
-  Handle<Object> result = handle(cache->get(index), cache->GetIsolate());
-  if (result->IsMap() &&
-      Handle<Map>::cast(result)->EquivalentToForNormalization(
-          *fast_map, mode)) {
-#ifdef VERIFY_HEAP
-    if (FLAG_verify_heap) {
-      Handle<Map>::cast(result)->SharedMapVerify();
-    }
-#endif
-#ifdef ENABLE_SLOW_ASSERTS
-    if (FLAG_enable_slow_asserts) {
-      // The cached map should match newly created normalized map bit-by-bit,
-      // except for the code cache, which can contain some ics which can be
-      // applied to the shared map.
-      Handle<Map> fresh = Map::CopyNormalized(
-          fast_map, mode, SHARED_NORMALIZED_MAP);
+Handle<NormalizedMapCache> NormalizedMapCache::New(Isolate* isolate) {
+  Handle<FixedArray> array(
+      isolate->factory()->NewFixedArray(kEntries, TENURED));
+  return Handle<NormalizedMapCache>::cast(array);
+}
 
-      ASSERT(memcmp(fresh->address(),
-                    Handle<Map>::cast(result)->address(),
-                    Map::kCodeCacheOffset) == 0);
-      STATIC_ASSERT(Map::kDependentCodeOffset ==
-                    Map::kCodeCacheOffset + kPointerSize);
-      int offset = Map::kDependentCodeOffset + kPointerSize;
-      ASSERT(memcmp(fresh->address() + offset,
-                    Handle<Map>::cast(result)->address() + offset,
-                    Map::kSize - offset) == 0);
-    }
-#endif
-    return Handle<Map>::cast(result);
+
+MaybeHandle<Map> NormalizedMapCache::Get(Handle<Map> fast_map,
+                                         PropertyNormalizationMode mode) {
+  DisallowHeapAllocation no_gc;
+  Object* value = FixedArray::get(GetIndex(fast_map));
+  if (!value->IsMap() ||
+      !Map::cast(value)->EquivalentToForNormalization(*fast_map, mode)) {
+    return MaybeHandle<Map>();
   }
+  return handle(Map::cast(value));
+}
 
-  Isolate* isolate = cache->GetIsolate();
-  Handle<Map> map = Map::CopyNormalized(fast_map, mode, SHARED_NORMALIZED_MAP);
-  ASSERT(map->is_dictionary_map());
-  cache->set(index, *map);
-  isolate->counters()->normalized_maps()->Increment();
 
-  return map;
+void NormalizedMapCache::Set(Handle<Map> fast_map,
+                             Handle<Map> normalized_map) {
+  DisallowHeapAllocation no_gc;
+  ASSERT(normalized_map->is_dictionary_map());
+  FixedArray::set(GetIndex(fast_map), *normalized_map);
 }
 
 
@@ -4733,6 +4715,7 @@ void JSObject::NormalizeProperties(Handle<JSObject> object,
   Isolate* isolate = object->GetIsolate();
   HandleScope scope(isolate);
   Handle<Map> map(object->map());
+  Handle<Map> new_map = Map::Normalize(map, mode);
 
   // Allocate new content.
   int real_size = map->NumberOfOwnDescriptors();
@@ -4787,12 +4770,6 @@ void JSObject::NormalizeProperties(Handle<JSObject> object,
   // Copy the next enumeration index from instance descriptor.
   dictionary->SetNextEnumerationIndex(real_size + 1);
 
-  Handle<NormalizedMapCache> cache(
-      isolate->context()->native_context()->normalized_map_cache());
-  Handle<Map> new_map = NormalizedMapCache::Get(
-      cache, handle(object->map()), mode);
-  ASSERT(new_map->is_dictionary_map());
-
   // From here on we cannot fail and we shouldn't GC anymore.
   DisallowHeapAllocation no_allocation;
 
@@ -4811,8 +4788,6 @@ void JSObject::NormalizeProperties(Handle<JSObject> object,
   // the left-over space to avoid races with the sweeper thread.
   object->synchronized_set_map(*new_map);
 
-  map->NotifyLeafMapLayoutChange();
-
   object->set_properties(*dictionary);
 
   isolate->counters()->props_to_dictionary()->Increment();
@@ -7239,6 +7214,50 @@ Handle<Map> Map::RawCopy(Handle<Map> map, int instance_size) {
 }
 
 
+Handle<Map> Map::Normalize(Handle<Map> fast_map,
+                           PropertyNormalizationMode mode) {
+  ASSERT(!fast_map->is_dictionary_map());
+
+  Isolate* isolate = fast_map->GetIsolate();
+  Handle<NormalizedMapCache> cache(
+      isolate->context()->native_context()->normalized_map_cache());
+
+  Handle<Map> new_map;
+  if (cache->Get(fast_map, mode).ToHandle(&new_map)) {
+#ifdef VERIFY_HEAP
+    if (FLAG_verify_heap) {
+      new_map->SharedMapVerify();
+    }
+#endif
+#ifdef ENABLE_SLOW_ASSERTS
+    if (FLAG_enable_slow_asserts) {
+      // The cached map should match newly created normalized map bit-by-bit,
+      // except for the code cache, which can contain some ics which can be
+      // applied to the shared map.
+      Handle<Map> fresh = Map::CopyNormalized(
+          fast_map, mode, SHARED_NORMALIZED_MAP);
+
+      ASSERT(memcmp(fresh->address(),
+                    new_map->address(),
+                    Map::kCodeCacheOffset) == 0);
+      STATIC_ASSERT(Map::kDependentCodeOffset ==
+                    Map::kCodeCacheOffset + kPointerSize);
+      int offset = Map::kDependentCodeOffset + kPointerSize;
+      ASSERT(memcmp(fresh->address() + offset,
+                    new_map->address() + offset,
+                    Map::kSize - offset) == 0);
+    }
+#endif
+  } else {
+    new_map = Map::CopyNormalized(fast_map, mode, SHARED_NORMALIZED_MAP);
+    cache->Set(fast_map, new_map);
+    isolate->counters()->normalized_maps()->Increment();
+  }
+  fast_map->NotifyLeafMapLayoutChange();
+  return new_map;
+}
+
+
 Handle<Map> Map::CopyNormalized(Handle<Map> map,
                                 PropertyNormalizationMode mode,
                                 NormalizedMapSharingMode sharing) {

src/objects.h

@@ -4628,18 +4628,27 @@ class ScopeInfo : public FixedArray {
 // needs very limited number of distinct normalized maps.
 class NormalizedMapCache: public FixedArray {
  public:
-  static const int kEntries = 64;
+  static Handle<NormalizedMapCache> New(Isolate* isolate);
 
-  static Handle<Map> Get(Handle<NormalizedMapCache> cache,
-                         Handle<Map> fast_map,
+  MUST_USE_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map,
                                        PropertyNormalizationMode mode);
+  void Set(Handle<Map> fast_map, Handle<Map> normalized_map);
 
   void Clear();
 
   // Casting
   static inline NormalizedMapCache* cast(Object* obj);
+  static inline bool IsNormalizedMapCache(Object* obj);
 
   DECLARE_VERIFIER(NormalizedMapCache)
+ private:
+  static const int kEntries = 64;
+
+  static inline int GetIndex(Handle<Map> map);
+
+  // The following declarations hide base class methods.
+  Object* get(int index);
+  void set(int index, Object* value);
 };
 
 
@@ -6134,6 +6143,8 @@ class Map: public HeapObject {
       PropertyAttributes attributes,
       const char* reason);
 
+  static Handle<Map> Normalize(Handle<Map> map, PropertyNormalizationMode mode);
+
   // Returns the constructor name (the name (possibly, inferred name) of the
   // function that was used to instantiate the object).
   String* constructor_name();
@@ -6327,10 +6338,6 @@ class Map: public HeapObject {
 
   static Handle<Map> CopyForFreeze(Handle<Map> map);
 
-  static Handle<Map> CopyNormalized(Handle<Map> map,
-                                    PropertyNormalizationMode mode,
-                                    NormalizedMapSharingMode sharing);
-
   inline void AppendDescriptor(Descriptor* desc);
 
   // Returns a copy of the map, with all transitions dropped from the
@@ -6424,11 +6431,6 @@ class Map: public HeapObject {
     return type == JS_GLOBAL_OBJECT_TYPE || type == JS_BUILTINS_OBJECT_TYPE;
   }
 
-  // Fires when the layout of an object with a leaf map changes.
-  // This includes adding transitions to the leaf map or changing
-  // the descriptor array.
-  inline void NotifyLeafMapLayoutChange();
-
   inline bool CanOmitMapChecks();
 
   static void AddDependentCompilationInfo(Handle<Map> map,
@@ -6578,6 +6580,15 @@ class Map: public HeapObject {
       MaybeHandle<Name> maybe_name,
       SimpleTransitionFlag simple_flag = FULL_TRANSITION);
 
+  static Handle<Map> CopyNormalized(Handle<Map> map,
+                                    PropertyNormalizationMode mode,
+                                    NormalizedMapSharingMode sharing);
+
+  // Fires when the layout of an object with a leaf map changes.
+  // This includes adding transitions to the leaf map or changing
+  // the descriptor array.
+  inline void NotifyLeafMapLayoutChange();
+
   // Zaps the contents of backing data structures. Note that the
   // heap verifier (i.e. VerifyMarkingVisitor) relies on zapping of objects
   // holding weak references when incremental marking is used, because it also