Store weak cell cache for map in the map itself.

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 5973 matching lines @@
                                 LayoutDescriptor* layout_descriptor);
   inline void InitializeDescriptors(DescriptorArray* descriptors,
                                     LayoutDescriptor* layout_descriptor);
 
   // [stub cache]: contains stubs compiled for this map.
   DECL_ACCESSORS(code_cache, Object)
 
   // [dependent code]: list of optimized codes that weakly embed this map.
   DECL_ACCESSORS(dependent_code, DependentCode)
 
+  // [weak cell cache]: cache that stores a weak cell pointing to this map.
+  DECL_ACCESSORS(weak_cell_cache, Object)
+
   // [prototype transitions]: cache of prototype transitions.
   // Prototype transition is a transition that happens
   // when we change object's prototype to a new one.
   // Cache format:
   //    0: finger - index of the first free cell in the cache
   //    1 + i: target map
   inline FixedArray* GetPrototypeTransitions();
   inline bool HasPrototypeTransitions();
 
   static const int kProtoTransitionNumberOfEntriesOffset = 0;
@@ skipping 285 matching lines @@
       kConstructorOrBackPointerOffset + kPointerSize;
   static const int kDescriptorsOffset = kTransitionsOffset + kPointerSize;
 #if V8_DOUBLE_FIELDS_UNBOXING
   static const int kLayoutDecriptorOffset = kDescriptorsOffset + kPointerSize;
   static const int kCodeCacheOffset = kLayoutDecriptorOffset + kPointerSize;
 #else
   static const int kLayoutDecriptorOffset = 1;  // Must not be ever accessed.
   static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize;
 #endif
   static const int kDependentCodeOffset = kCodeCacheOffset + kPointerSize;
-  static const int kSize = kDependentCodeOffset + kPointerSize;
+  static const int kWeakCellCacheOffset = kDependentCodeOffset + kPointerSize;
+  static const int kSize = kWeakCellCacheOffset + kPointerSize;
 
   // Layout of pointer fields. Heap iteration code relies on them
   // being continuously allocated.
   static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset;
   static const int kPointerFieldsEndOffset = kSize;
 
   // Byte offsets within kInstanceSizesOffset.
   static const int kInstanceSizeOffset = kInstanceSizesOffset + 0;
   static const int kInObjectPropertiesByte = 1;
   static const int kInObjectPropertiesOffset =
@@ skipping 1791 matching lines @@
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable);
 };
 
 
 class CodeCache: public Struct {
  public:
   DECL_ACCESSORS(default_cache, FixedArray)
   DECL_ACCESSORS(normal_type_cache, Object)
-  DECL_ACCESSORS(weak_cell_cache, Object)
 
   // Add the code object to the cache.
   static void Update(
       Handle<CodeCache> cache, Handle<Name> name, Handle<Code> code);
 
   // Lookup code object in the cache. Returns code object if found and undefined
   // if not.
   Object* Lookup(Name* name, Code::Flags flags);
 
   // Get the internal index of a code object in the cache. Returns -1 if the
   // code object is not in that cache. This index can be used to later call
   // RemoveByIndex. The cache cannot be modified between a call to GetIndex and
   // RemoveByIndex.
   int GetIndex(Object* name, Code* code);
 
   // Remove an object from the cache with the provided internal index.
   void RemoveByIndex(Object* name, Code* code, int index);
 
   DECLARE_CAST(CodeCache)
 
   // Dispatched behavior.
   DECLARE_PRINTER(CodeCache)
   DECLARE_VERIFIER(CodeCache)
 
   static const int kDefaultCacheOffset = HeapObject::kHeaderSize;
   static const int kNormalTypeCacheOffset =
       kDefaultCacheOffset + kPointerSize;
-  static const int kWeakCellCacheOffset = kNormalTypeCacheOffset + kPointerSize;
-  static const int kSize = kWeakCellCacheOffset + kPointerSize;
+  static const int kSize = kNormalTypeCacheOffset + kPointerSize;
 
  private:
   static void UpdateDefaultCache(
       Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
   static void UpdateNormalTypeCache(
       Handle<CodeCache> code_cache, Handle<Name> name, Handle<Code> code);
   Object* LookupDefaultCache(Name* name, Code::Flags flags);
   Object* LookupNormalTypeCache(Name* name, Code::Flags flags);
 
   // Code cache layout of the default cache. Elements are alternating name and
@@ skipping 2827 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_