Backport @10366 to 3.6

src/objects.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2496 matching lines @@
 //     // The prefix size indicates number of elements in the beginning
 //     // of the backing storage.
 //     static const int kPrefixSize = ..;
 //     // The Element size indicates number of elements per entry.
 //     static const int kEntrySize = ..;
 //   };
 // The prefix size indicates an amount of memory in the
 // beginning of the backing storage that can be used for non-element
 // information by subclasses.
 
+template<typename Key>
+class BaseShape {
+ public:
+  static const bool UsesSeed = false;
+  static uint32_t Hash(Key key) { return 0; }
+  static uint32_t SeededHash(Key key, uint32_t seed) {
+    ASSERT(UsesSeed);
+    return Hash(key);
+  }
+  static uint32_t HashForObject(Key key, Object* object) { return 0; }
+  static uint32_t SeededHashForObject(Key key, uint32_t seed, Object* object) {
+    // Won't be called if UsesSeed isn't overridden by child class.
+    return HashForObject(key, object);
+  }
+};
+
 template<typename Shape, typename Key>
 class HashTable: public FixedArray {
  public:
+  // Wrapper methods
+  inline uint32_t Hash(Key key) {
+    if (Shape::UsesSeed) {
+      return Shape::SeededHash(key,
+          GetHeap()->HashSeed());
+    } else {
+      return Shape::Hash(key);
+    }
+  }
+
+  inline uint32_t HashForObject(Key key, Object* object) {
+    if (Shape::UsesSeed) {
+      return Shape::SeededHashForObject(key,
+          GetHeap()->HashSeed(), object);
+    } else {
+      return Shape::HashForObject(key, object);
+    }
+  }
+
   // Returns the number of elements in the hash table.
   int NumberOfElements() {
     return Smi::cast(get(kNumberOfElementsIndex))->value();
   }
 
   // Returns the number of deleted elements in the hash table.
   int NumberOfDeletedElements() {
     return Smi::cast(get(kNumberOfDeletedElementsIndex))->value();
   }
 
@@ skipping 121 matching lines @@
   MUST_USE_RESULT MaybeObject* Rehash(HashTable* new_table, Key key);
 
   // Attempt to shrink hash table after removal of key.
   MUST_USE_RESULT MaybeObject* Shrink(Key key);
 
   // Ensure enough space for n additional elements.
   MUST_USE_RESULT MaybeObject* EnsureCapacity(int n, Key key);
 };
 
 
-
 // HashTableKey is an abstract superclass for virtual key behavior.
 class HashTableKey {
  public:
   // Returns whether the other object matches this key.
   virtual bool IsMatch(Object* other) = 0;
   // Returns the hash value for this key.
   virtual uint32_t Hash() = 0;
   // Returns the hash value for object.
   virtual uint32_t HashForObject(Object* key) = 0;
   // Returns the key object for storing into the hash table.
   // If allocations fails a failure object is returned.
   MUST_USE_RESULT virtual MaybeObject* AsObject() = 0;
   // Required.
   virtual ~HashTableKey() {}
 };
 
-class SymbolTableShape {
+
+class SymbolTableShape : public BaseShape<HashTableKey*> {
  public:
   static inline bool IsMatch(HashTableKey* key, Object* value) {
     return key->IsMatch(value);
   }
   static inline uint32_t Hash(HashTableKey* key) {
     return key->Hash();
   }
   static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
     return key->HashForObject(object);
   }
@@ skipping 38 matching lines @@
   // Casting.
   static inline SymbolTable* cast(Object* obj);
 
  private:
   MUST_USE_RESULT MaybeObject* LookupKey(HashTableKey* key, Object** s);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(SymbolTable);
 };
 
 
-class MapCacheShape {
+class MapCacheShape : public BaseShape<HashTableKey*> {
  public:
   static inline bool IsMatch(HashTableKey* key, Object* value) {
     return key->IsMatch(value);
   }
   static inline uint32_t Hash(HashTableKey* key) {
     return key->Hash();
   }
 
   static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
     return key->HashForObject(object);
@@ skipping 135 matching lines @@
                                         uint32_t hash);
 
   // Generate new enumeration indices to avoid enumeration index overflow.
   MUST_USE_RESULT MaybeObject* GenerateNewEnumerationIndices();
   static const int kMaxNumberKeyIndex =
       HashTable<Shape, Key>::kPrefixStartIndex;
   static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1;
 };
 
 
-class StringDictionaryShape {
+class StringDictionaryShape : public BaseShape<String*> {
  public:
   static inline bool IsMatch(String* key, Object* other);
   static inline uint32_t Hash(String* key);
   static inline uint32_t HashForObject(String* key, Object* object);
   MUST_USE_RESULT static inline MaybeObject* AsObject(String* key);
   static const int kPrefixSize = 2;
   static const int kEntrySize = 3;
   static const bool kIsEnumerable = true;
 };
 
@@ skipping 12 matching lines @@
   MUST_USE_RESULT MaybeObject* TransformPropertiesToFastFor(
       JSObject* obj,
       int unused_property_fields);
 
   // Find entry for key otherwise return kNotFound. Optimzed version of
   // HashTable::FindEntry.
   int FindEntry(String* key);
 };
 
 
-class NumberDictionaryShape {
+class NumberDictionaryShape : public BaseShape<uint32_t> {
  public:
+  static const bool UsesSeed = true;
+
   static inline bool IsMatch(uint32_t key, Object* other);
   static inline uint32_t Hash(uint32_t key);
+  static inline uint32_t SeededHash(uint32_t key, uint32_t seed);
   static inline uint32_t HashForObject(uint32_t key, Object* object);
+  static inline uint32_t SeededHashForObject(uint32_t key,
+                                             uint32_t seed,
+                                             Object* object);
   MUST_USE_RESULT static inline MaybeObject* AsObject(uint32_t key);
   static const int kPrefixSize = 2;
   static const int kEntrySize = 3;
   static const bool kIsEnumerable = false;
 };
 
 
 class NumberDictionary: public Dictionary<NumberDictionaryShape, uint32_t> {
  public:
   static NumberDictionary* cast(Object* obj) {
@@ skipping 30 matching lines @@
   // Remove all entries were key is a number and (from <= key && key < to).
   void RemoveNumberEntries(uint32_t from, uint32_t to);
 
   // Bit masks.
   static const int kRequiresSlowElementsMask = 1;
   static const int kRequiresSlowElementsTagSize = 1;
   static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1;
 };
 
 
-class ObjectHashTableShape {
+class ObjectHashTableShape : public BaseShape<Object*> {
  public:
   static inline bool IsMatch(JSObject* key, Object* other);
   static inline uint32_t Hash(JSObject* key);
   static inline uint32_t HashForObject(JSObject* key, Object* object);
   MUST_USE_RESULT static inline MaybeObject* AsObject(JSObject* key);
   static const int kPrefixSize = 0;
   static const int kEntrySize = 2;
 };
 
 
@@ skipping 2544 matching lines @@
   // object is in the saved code field.
   static const int kCompilationErrorValue = -2;
 
   // When we store the sweep generation at which we moved the code from the
   // code index to the saved code index we mask it of to be in the [0:255]
   // range.
   static const int kCodeAgeMask = 0xff;
 };
 
 
-class CompilationCacheShape {
+class CompilationCacheShape : public BaseShape<HashTableKey*> {
  public:
   static inline bool IsMatch(HashTableKey* key, Object* value) {
     return key->IsMatch(value);
   }
 
   static inline uint32_t Hash(HashTableKey* key) {
     return key->Hash();
   }
 
   static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
@@ skipping 79 matching lines @@
   // Code cache layout of the default cache. Elements are alternating name and
   // code objects for non normal load/store/call IC's.
   static const int kCodeCacheEntrySize = 2;
   static const int kCodeCacheEntryNameOffset = 0;
   static const int kCodeCacheEntryCodeOffset = 1;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache);
 };
 
 
-class CodeCacheHashTableShape {
+class CodeCacheHashTableShape : public BaseShape<HashTableKey*> {
  public:
   static inline bool IsMatch(HashTableKey* key, Object* value) {
     return key->IsMatch(value);
   }
 
   static inline uint32_t Hash(HashTableKey* key) {
     return key->Hash();
   }
 
   static inline uint32_t HashForObject(HashTableKey* key, Object* object) {
@@ skipping 1841 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_