Move hash code from hidden string to a private symbol

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 1202 matching lines @@
       Isolate* isolate, Handle<Object> object, Handle<Object> receiver,
       uint32_t index, Handle<Object> value, LanguageMode language_mode);
 
   static inline Handle<Object> GetPrototypeSkipHiddenPrototypes(
       Isolate* isolate, Handle<Object> receiver);
 
   // Returns the permanent hash code associated with this object. May return
   // undefined if not yet created.
   Object* GetHash();
 
+  // Returns undefined for JSObjects, but returns the hash code for simple
+  // objects.  This avoids a double lookup in the cases where we know we will
+  // add the hash to the JSObject if it does not already exist.
+  Object* GetSimpleHash();
+
   // Returns the permanent hash code associated with this object depending on
   // the actual object type. May create and store a hash code if needed and none
   // exists.
   static Handle<Smi> GetOrCreateHash(Isolate* isolate, Handle<Object> object);
 
   // Checks whether this object has the same value as the given one.  This
   // function is implemented according to ES5, section 9.12 and can be used
   // to implement the Harmony "egal" function.
   bool SameValue(Object* other);
 
@@ skipping 2196 matching lines @@
       PretenureFlag pretenure = NOT_TENURED);
 
   DECLARE_CAST(HashTable)
 
   // Garbage collection support.
   void IteratePrefix(ObjectVisitor* visitor);
   void IterateElements(ObjectVisitor* visitor);
 
   // Find entry for key otherwise return kNotFound.
   inline int FindEntry(Key key);
+  inline int FindEntry(Isolate* isolate, Key key, int32_t hash);
   int FindEntry(Isolate* isolate, Key key);
 
   // Rehashes the table in-place.
   void Rehash(Key key);
 
   // Returns the key at entry.
   Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
 
   static const int kElementsStartIndex = kPrefixStartIndex + Shape::kPrefixSize;
   static const int kEntrySize = Shape::kEntrySize;
@@ skipping 486 matching lines @@
   DECLARE_CAST(ObjectHashTable)
 
   // Attempt to shrink hash table after removal of key.
   MUST_USE_RESULT static inline Handle<ObjectHashTable> Shrink(
       Handle<ObjectHashTable> table,
       Handle<Object> key);
 
   // Looks up the value associated with the given key. The hole value is
   // returned in case the key is not present.
   Object* Lookup(Handle<Object> key);
+  Object* Lookup(Handle<Object> key, int32_t hash);
 
   // Adds (or overwrites) the value associated with the given key.
   static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
                                      Handle<Object> key,
                                      Handle<Object> value);
+  static Handle<ObjectHashTable> Put(Handle<ObjectHashTable> table,
+                                     Handle<Object> key, Handle<Object> value,
+                                     int32_t hash);
 
   // Returns an ObjectHashTable (possibly |table|) where |key| has been removed.
   static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
                                         Handle<Object> key,
                                         bool* was_present);
+  static Handle<ObjectHashTable> Remove(Handle<ObjectHashTable> table,
+                                        Handle<Object> key, bool* was_present,
+                                        int32_t hash);
 
  private:
   friend class MarkCompactCollector;
 
   void AddEntry(int entry, Object* key, Object* value);
   void RemoveEntry(int entry);
 
   // Returns the index to the value of an entry.
   static inline int EntryToValueIndex(int entry) {
     return EntryToIndex(entry) + 1;
@@ skipping 7166 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_