Reland parts of 'Use weak cells in map checks in polymorphic ICs'

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 6172 matching lines @@
                                           CompilationInfo* info);
 
   static void AddDependentCode(Handle<Map> map,
                                DependentCode::DependencyGroup group,
                                Handle<Code> code);
   static void AddDependentIC(Handle<Map> map,
                              Handle<Code> stub);
 
   bool IsMapInArrayPrototypeChain();
 
+  static Handle<WeakCell> WeakCellForMap(Handle<Map> map);
+
   // Dispatched behavior.
   DECLARE_PRINTER(Map)
   DECLARE_VERIFIER(Map)
 
 #ifdef VERIFY_HEAP
   void DictionaryMapVerify();
   void VerifyOmittedMapChecks();
 #endif
 
   inline int visitor_id();
@@ skipping 1815 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 kSize = kNormalTypeCacheOffset + kPointerSize;
+  static const int kWeakCellCacheOffset = kNormalTypeCacheOffset + kPointerSize;
+  static const int kSize = kWeakCellCacheOffset + 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 2931 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_