Merge (7265, 7271] from bleeding_edge to experimental/gc branch....

src/objects-inl.h

 // Copyright 2010 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 22 matching lines @@
 //
 
 #ifndef V8_OBJECTS_INL_H_
 #define V8_OBJECTS_INL_H_
 
 #include "objects.h"
 #include "contexts.h"
 #include "conversions-inl.h"
 #include "heap.h"
 #include "memory.h"
+#include "isolate.h"
 #include "property.h"
 #include "spaces.h"
 #include "store-buffer.h"
 
 #include "incremental-marking.h"
 
 namespace v8 {
 namespace internal {
 
 PropertyDetails::PropertyDetails(Smi* smi) {
@@ skipping 21 matching lines @@
 
 #define INT_ACCESSORS(holder, name, offset)                             \
   int holder::name() { return READ_INT_FIELD(this, offset); }           \
   void holder::set_##name(int value) { WRITE_INT_FIELD(this, offset, value); }
 
 
 #define ACCESSORS(holder, name, type, offset)                           \
   type* holder::name() { return type::cast(READ_FIELD(this, offset)); } \
   void holder::set_##name(type* value, WriteBarrierMode mode) {         \
     WRITE_FIELD(this, offset, value);                                   \
-    WRITE_BARRIER(this, offset, value);                                 \
+    WRITE_BARRIER(GetHeap(), this, offset, value);                       \
+  }
+
+
+// GC-safe accessors do not use HeapObject::GetHeap(), but access TLS instead.
+#define ACCESSORS_GCSAFE(holder, name, type, offset)                    \
+  type* holder::name() { return type::cast(READ_FIELD(this, offset)); } \
+  void holder::set_##name(type* value, WriteBarrierMode mode) {         \
+    WRITE_FIELD(this, offset, value);                                   \
+    WRITE_BARRIER(HEAP, this, offset, value);                \
   }
 
 
 #define SMI_ACCESSORS(holder, name, offset)             \
   int holder::name() {                                  \
     Object* value = READ_FIELD(this, offset);           \
     return Smi::cast(value)->value();                   \
   }                                                     \
   void holder::set_##name(int value) {                  \
     WRITE_FIELD(this, offset, Smi::FromInt(value));     \
@@ skipping 339 matching lines @@
       && Failure::cast(this)->IsOutOfMemoryException();
 }
 
 
 bool MaybeObject::IsException() {
   return this == Failure::Exception();
 }
 
 
 bool MaybeObject::IsTheHole() {
-  return this == Heap::the_hole_value();
+  return !IsFailure() && ToObjectUnchecked()->IsTheHole();
 }
 
 
 Failure* Failure::cast(MaybeObject* obj) {
   ASSERT(HAS_FAILURE_TAG(obj));
   return reinterpret_cast<Failure*>(obj);
 }
 
 
 bool Object::IsJSObject() {
@@ skipping 47 matching lines @@
   if (!IsFixedArray()) return false;
   // There's actually no way to see the difference between a fixed array and
   // a deoptimization data array.  Since this is used for asserts we can check
   // that the length is plausible though.
   if (FixedArray::cast(this)->length() % 2 != 0) return false;
   return true;
 }
 
 
 bool Object::IsContext() {
-  return Object::IsHeapObject()
-    && (HeapObject::cast(this)->map() == Heap::context_map() ||
-        HeapObject::cast(this)->map() == Heap::catch_context_map() ||
-        HeapObject::cast(this)->map() == Heap::global_context_map());
+  if (Object::IsHeapObject()) {
+    Heap* heap = HeapObject::cast(this)->GetHeap();
+    return (HeapObject::cast(this)->map() == heap->context_map() ||
+            HeapObject::cast(this)->map() == heap->catch_context_map() ||
+            HeapObject::cast(this)->map() == heap->global_context_map());
+  }
+  return false;
 }
 
 
 bool Object::IsCatchContext() {
-  return Object::IsHeapObject()
-      && HeapObject::cast(this)->map() == Heap::catch_context_map();
+  return Object::IsHeapObject() &&
+      HeapObject::cast(this)->map() ==
+      HeapObject::cast(this)->GetHeap()->catch_context_map();
 }
 
 
 bool Object::IsGlobalContext() {
-  return Object::IsHeapObject()
-      && HeapObject::cast(this)->map() == Heap::global_context_map();
+  return Object::IsHeapObject() &&
+      HeapObject::cast(this)->map() ==
+      HeapObject::cast(this)->GetHeap()->global_context_map();
 }
 
 
 bool Object::IsJSFunction() {
   return Object::IsHeapObject()
       && HeapObject::cast(this)->map()->instance_type() == JS_FUNCTION_TYPE;
 }
 
 
 template <> inline bool Is<JSFunction>(Object* obj) {
@@ skipping 45 matching lines @@
 }
 
 
 bool Object::IsProxy() {
   return Object::IsHeapObject()
       && HeapObject::cast(this)->map()->instance_type() == PROXY_TYPE;
 }
 
 
 bool Object::IsBoolean() {
-  return IsTrue() || IsFalse();
+  return IsOddball() &&
+      ((Oddball::cast(this)->kind() & Oddball::kNotBooleanMask) == 0);
 }
 
 
 bool Object::IsJSArray() {
   return Object::IsHeapObject()
       && HeapObject::cast(this)->map()->instance_type() == JS_ARRAY_TYPE;
 }
 
 
 bool Object::IsJSRegExp() {
   return Object::IsHeapObject()
       && HeapObject::cast(this)->map()->instance_type() == JS_REGEXP_TYPE;
 }
 
 
 template <> inline bool Is<JSArray>(Object* obj) {
   return obj->IsJSArray();
 }
 
 
 bool Object::IsHashTable() {
-  return Object::IsHeapObject()
-      && HeapObject::cast(this)->map() == Heap::hash_table_map();
+  return Object::IsHeapObject() &&
+      HeapObject::cast(this)->map() ==
+      HeapObject::cast(this)->GetHeap()->hash_table_map();
 }
 
 
 bool Object::IsDictionary() {
-  return IsHashTable() && this != Heap::symbol_table();
+  return IsHashTable() && this !=
+         HeapObject::cast(this)->GetHeap()->symbol_table();
 }
 
 
 bool Object::IsSymbolTable() {
-  return IsHashTable() && this == Heap::raw_unchecked_symbol_table();
+  return IsHashTable() && this ==
+         HeapObject::cast(this)->GetHeap()->raw_unchecked_symbol_table();
 }
 
 
 bool Object::IsJSFunctionResultCache() {
   if (!IsFixedArray()) return false;
   FixedArray* self = FixedArray::cast(this);
   int length = self->length();
   if (length < JSFunctionResultCache::kEntriesIndex) return false;
   if ((length - JSFunctionResultCache::kEntriesIndex)
       % JSFunctionResultCache::kEntrySize != 0) {
@@ skipping 96 matching lines @@
 #define MAKE_STRUCT_PREDICATE(NAME, Name, name)                  \
   bool Object::Is##Name() {                                      \
     return Object::IsHeapObject()                                \
       && HeapObject::cast(this)->map()->instance_type() == NAME##_TYPE; \
   }
   STRUCT_LIST(MAKE_STRUCT_PREDICATE)
 #undef MAKE_STRUCT_PREDICATE
 
 
 bool Object::IsUndefined() {
-  return this == Heap::undefined_value();
+  return IsOddball() && Oddball::cast(this)->kind() == Oddball::kUndefined;
 }
 
 
 bool Object::IsNull() {
-  return this == Heap::null_value();
+  return IsOddball() && Oddball::cast(this)->kind() == Oddball::kNull;
+}
+
+
+bool Object::IsTheHole() {
+  return IsOddball() && Oddball::cast(this)->kind() == Oddball::kTheHole;
 }
 
 
 bool Object::IsTrue() {
-  return this == Heap::true_value();
+  return IsOddball() && Oddball::cast(this)->kind() == Oddball::kTrue;
 }
 
 
 bool Object::IsFalse() {
-  return this == Heap::false_value();
+  return IsOddball() && Oddball::cast(this)->kind() == Oddball::kFalse;
 }
 
 
 bool Object::IsArgumentsMarker() {
-  return this == Heap::arguments_marker();
+  return IsOddball() && Oddball::cast(this)->kind() == Oddball::kArgumentMarker;
 }
 
 
 double Object::Number() {
   ASSERT(IsNumber());
   return IsSmi()
     ? static_cast<double>(reinterpret_cast<Smi*>(this)->value())
     : reinterpret_cast<HeapNumber*>(this)->value();
 }
 
 
-
 MaybeObject* Object::ToSmi() {
   if (IsSmi()) return this;
   if (IsHeapNumber()) {
     double value = HeapNumber::cast(this)->value();
     int int_value = FastD2I(value);
     if (value == FastI2D(int_value) && Smi::IsValid(int_value)) {
       return Smi::FromInt(int_value);
     }
   }
   return Failure::Exception();
 }
 
 
 bool Object::HasSpecificClassOf(String* name) {
   return this->IsJSObject() && (JSObject::cast(this)->class_name() == name);
 }
 
 
 MaybeObject* Object::GetElement(uint32_t index) {
   // GetElement can trigger a getter which can cause allocation.
   // This was not always the case. This ASSERT is here to catch
   // leftover incorrect uses.
-  ASSERT(Heap::IsAllocationAllowed());
+  ASSERT(HEAP->IsAllocationAllowed());
   return GetElementWithReceiver(this, index);
 }
 
 
 Object* Object::GetElementNoExceptionThrown(uint32_t index) {
   MaybeObject* maybe = GetElementWithReceiver(this, index);
   ASSERT(!maybe->IsFailure());
   Object* result = NULL;  // Initialization to please compiler.
   maybe->ToObject(&result);
   return result;
@@ skipping 13 matching lines @@
 
 #define FIELD_ADDR(p, offset) \
   (reinterpret_cast<byte*>(p) + offset - kHeapObjectTag)
 
 #define READ_FIELD(p, offset) \
   (*reinterpret_cast<Object**>(FIELD_ADDR(p, offset)))
 
 #define WRITE_FIELD(p, offset, value) \
   (*reinterpret_cast<Object**>(FIELD_ADDR(p, offset)) = value)
 
-#define WRITE_BARRIER(object, offset, value) \
-  IncrementalMarking::RecordWrite(object, value); \
-  if (Heap::InNewSpace(value)) { \
-    Heap::RecordWrite(object->address(), offset); \
+#define WRITE_BARRIER(heap, object, offset, value) \
+  heap->incremental_marking()->RecordWrite(object, value); \
+  if (HEAP->InNewSpace(value)) { \
+    heap->RecordWrite(object->address(), offset); \
   }
 
+// TODO(gc) !!!
+
 #define READ_DOUBLE_FIELD(p, offset) \
   (*reinterpret_cast<double*>(FIELD_ADDR(p, offset)))
 
 #define WRITE_DOUBLE_FIELD(p, offset, value) \
   (*reinterpret_cast<double*>(FIELD_ADDR(p, offset)) = value)
 
 #define READ_INT_FIELD(p, offset) \
   (*reinterpret_cast<int*>(FIELD_ADDR(p, offset)))
 
 #define WRITE_INT_FIELD(p, offset, value) \
@@ skipping 170 matching lines @@
 void HeapObject::VerifyObjectField(int offset) {
   VerifyPointer(READ_FIELD(this, offset));
 }
 
 void HeapObject::VerifySmiField(int offset) {
   ASSERT(READ_FIELD(this, offset)->IsSmi());
 }
 #endif
 
 
+Heap* HeapObject::GetHeap() {
+  // During GC, the map pointer in HeapObject is used in various ways that
+  // prevent us from retrieving Heap from the map.
+  // Assert that we are not in GC, implement GC code in a way that it doesn't
+  // pull heap from the map.
+  return map()->heap();
+}
+
+
+Isolate* HeapObject::GetIsolate() {
+  Isolate* i = GetHeap()->isolate();
+  ASSERT(i == Isolate::Current());
+  return i;
+}
+
+
 Map* HeapObject::map() {
   return map_word().ToMap();
 }
 
 
 void HeapObject::set_map(Map* value) {
   set_map_word(MapWord::FromMap(value));
-  IncrementalMarking::RecordWrite(this, value);
+  if (value != NULL) {
+    value->heap()->incremental_marking()->RecordWrite(this, value);
+  }
 }
 
 
 MapWord HeapObject::map_word() {
   return MapWord(reinterpret_cast<uintptr_t>(READ_FIELD(this, kMapOffset)));
 }
 
 
 void HeapObject::set_map_word(MapWord map_word) {
   // WRITE_FIELD does not invoke write barrier, but there is no need
@@ skipping 56 matching lines @@
 HeapObject* JSObject::elements() {
   Object* array = READ_FIELD(this, kElementsOffset);
   // In the assert below Dictionary is covered under FixedArray.
   ASSERT(array->IsFixedArray() || array->IsExternalArray());
   return reinterpret_cast<HeapObject*>(array);
 }
 
 
 void JSObject::set_elements(HeapObject* value, WriteBarrierMode mode) {
   ASSERT(map()->has_fast_elements() ==
-         (value->map() == Heap::fixed_array_map() ||
-          value->map() == Heap::fixed_cow_array_map()));
+         (value->map() == GetHeap()->fixed_array_map() ||
+          value->map() == GetHeap()->fixed_cow_array_map()));
   // In the assert below Dictionary is covered under FixedArray.
   ASSERT(value->IsFixedArray() || value->IsExternalArray());
   WRITE_FIELD(this, kElementsOffset, value);
-  WRITE_BARRIER(this, kElementsOffset, value);
+  WRITE_BARRIER(GetHeap(), this, kElementsOffset, value);
 }
 
 
 void JSObject::initialize_properties() {
-  ASSERT(!Heap::InNewSpace(Heap::empty_fixed_array()));
-  WRITE_FIELD(this, kPropertiesOffset, Heap::empty_fixed_array());
+  ASSERT(!GetHeap()->InNewSpace(GetHeap()->empty_fixed_array()));
+  WRITE_FIELD(this, kPropertiesOffset, GetHeap()->empty_fixed_array());
 }
 
 
 void JSObject::initialize_elements() {
   ASSERT(map()->has_fast_elements());
-  ASSERT(!Heap::InNewSpace(Heap::empty_fixed_array()));
-  WRITE_FIELD(this, kElementsOffset, Heap::empty_fixed_array());
+  ASSERT(!GetHeap()->InNewSpace(GetHeap()->empty_fixed_array()));
+  WRITE_FIELD(this, kElementsOffset, GetHeap()->empty_fixed_array());
 }
 
 
 MaybeObject* JSObject::ResetElements() {
   Object* obj;
   { MaybeObject* maybe_obj = map()->GetFastElementsMap();
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   set_map(Map::cast(obj));
   initialize_elements();
   return this;
 }
 
 
 ACCESSORS(Oddball, to_string, String, kToStringOffset)
 ACCESSORS(Oddball, to_number, Object, kToNumberOffset)
 
 
+byte Oddball::kind() {
+  return READ_BYTE_FIELD(this, kKindOffset);
+}
+
+
+void Oddball::set_kind(byte value) {
+  WRITE_BYTE_FIELD(this, kKindOffset, value);
+}
+
+
 Object* JSGlobalPropertyCell::value() {
   return READ_FIELD(this, kValueOffset);
 }
 
 
 void JSGlobalPropertyCell::set_value(Object* val, WriteBarrierMode ignored) {
   // The write barrier is not used for global property cells.
   ASSERT(!val->IsJSGlobalPropertyCell());
   WRITE_FIELD(this, kValueOffset, val);
-  IncrementalMarking::RecordWrite(this, val);
+  // TODO(gc) ISOLATES MERGE cell should heap accessor.
+  GetHeap()->incremental_marking()->RecordWrite(this, val);
 }
 
 
 int JSObject::GetHeaderSize() {
   InstanceType type = map()->instance_type();
   // Check for the most common kind of JavaScript object before
   // falling into the generic switch. This speeds up the internal
   // field operations considerably on average.
   if (type == JS_OBJECT_TYPE) return JSObject::kHeaderSize;
   switch (type) {
@@ skipping 46 matching lines @@
 }
 
 
 void JSObject::SetInternalField(int index, Object* value) {
   ASSERT(index < GetInternalFieldCount() && index >= 0);
   // Internal objects do follow immediately after the header, whereas in-object
   // properties are at the end of the object. Therefore there is no need
   // to adjust the index here.
   int offset = GetHeaderSize() + (kPointerSize * index);
   WRITE_FIELD(this, offset, value);
-  WRITE_BARRIER(this, offset, value);
+  WRITE_BARRIER(GetHeap(), this, offset, value);
 }
 
 
 // Access fast-case object properties at index. The use of these routines
 // is needed to correctly distinguish between properties stored in-object and
 // properties stored in the properties array.
 Object* JSObject::FastPropertyAt(int index) {
   // Adjust for the number of properties stored in the object.
   index -= map()->inobject_properties();
   if (index < 0) {
     int offset = map()->instance_size() + (index * kPointerSize);
     return READ_FIELD(this, offset);
   } else {
     ASSERT(index < properties()->length());
     return properties()->get(index);
   }
 }
 
 
 Object* JSObject::FastPropertyAtPut(int index, Object* value) {
   // Adjust for the number of properties stored in the object.
   index -= map()->inobject_properties();
   if (index < 0) {
     int offset = map()->instance_size() + (index * kPointerSize);
     WRITE_FIELD(this, offset, value);
-    WRITE_BARRIER(this, offset, value);
+    WRITE_BARRIER(GetHeap(), this, offset, value);
   } else {
     ASSERT(index < properties()->length());
     properties()->set(index, value);
   }
   return value;
 }
 
 
 int JSObject::GetInObjectPropertyOffset(int index) {
   // Adjust for the number of properties stored in the object.
@@ skipping 13 matching lines @@
 
 
 Object* JSObject::InObjectPropertyAtPut(int index,
                                         Object* value,
                                         WriteBarrierMode mode) {
   // Adjust for the number of properties stored in the object.
   index -= map()->inobject_properties();
   ASSERT(index < 0);
   int offset = map()->instance_size() + (index * kPointerSize);
   WRITE_FIELD(this, offset, value);
-  WRITE_BARRIER(this, offset, value);
+  WRITE_BARRIER(GetHeap(), this, offset, value);
   return value;
 }
 
 
 
 void JSObject::InitializeBody(int object_size, Object* value) {
-  ASSERT(!value->IsHeapObject() || !Heap::InNewSpace(value));
+  ASSERT(!value->IsHeapObject() || !GetHeap()->InNewSpace(value));
   for (int offset = kHeaderSize; offset < object_size; offset += kPointerSize) {
     WRITE_FIELD(this, offset, value);
   }
 }
 
 
 bool JSObject::HasFastProperties() {
   return !properties()->IsDictionary();
 }
 
 
 int JSObject::MaxFastProperties() {
   // Allow extra fast properties if the object has more than
   // kMaxFastProperties in-object properties. When this is the case,
   // it is very unlikely that the object is being used as a dictionary
   // and there is a good chance that allowing more map transitions
   // will be worth it.
   return Max(map()->inobject_properties(), kMaxFastProperties);
 }
 
 
 void Struct::InitializeBody(int object_size) {
-  Object* value = Heap::undefined_value();
+  Object* value = GetHeap()->undefined_value();
   for (int offset = kHeaderSize; offset < object_size; offset += kPointerSize) {
     WRITE_FIELD(this, offset, value);
   }
 }
 
 
 bool Object::ToArrayIndex(uint32_t* index) {
   if (IsSmi()) {
     int value = Smi::cast(this)->value();
     if (value < 0) return false;
@@ skipping 25 matching lines @@
 }
 
 
 Object* FixedArray::get(int index) {
   ASSERT(index >= 0 && index < this->length());
   return READ_FIELD(this, kHeaderSize + index * kPointerSize);
 }
 
 
 void FixedArray::set(int index, Smi* value) {
-  ASSERT(map() != Heap::fixed_cow_array_map());
+  ASSERT(map() != HEAP->fixed_cow_array_map());
   ASSERT(reinterpret_cast<Object*>(value)->IsSmi());
   int offset = kHeaderSize + index * kPointerSize;
   WRITE_FIELD(this, offset, value);
 }
 
 
 void FixedArray::set(int index, Object* value) {
-  ASSERT(map() != Heap::fixed_cow_array_map());
+  ASSERT(map() != HEAP->fixed_cow_array_map());
   ASSERT(index >= 0 && index < this->length());
   int offset = kHeaderSize + index * kPointerSize;
   WRITE_FIELD(this, offset, value);
-  WRITE_BARRIER(this, offset, value);
+  WRITE_BARRIER(GetHeap(), this, offset, value);
 }
 
 
 WriteBarrierMode HeapObject::GetWriteBarrierMode(const AssertNoAllocation&) {
-  if (Heap::InNewSpace(this)) return SKIP_WRITE_BARRIER;
+  if (GetHeap()->InNewSpace(this)) return SKIP_WRITE_BARRIER;
   return UPDATE_WRITE_BARRIER;
 }
 
 
 void FixedArray::set(int index,
                      Object* value,
                      WriteBarrierMode mode) {
-  ASSERT(map() != Heap::fixed_cow_array_map());
+  ASSERT(map() != HEAP->fixed_cow_array_map());
   ASSERT(index >= 0 && index < this->length());
   int offset = kHeaderSize + index * kPointerSize;
   WRITE_FIELD(this, offset, value);
-  WRITE_BARRIER(this, offset, value);
+  WRITE_BARRIER(GetHeap(), this, offset, value);
 }
 
 
 void FixedArray::fast_set(FixedArray* array, int index, Object* value) {
-  ASSERT(array->map() != Heap::raw_unchecked_fixed_cow_array_map());
+  ASSERT(array->map() != HEAP->raw_unchecked_fixed_cow_array_map());
   ASSERT(index >= 0 && index < array->length());
-  ASSERT(!Heap::InNewSpace(value));
+  ASSERT(!HEAP->InNewSpace(value));
   WRITE_FIELD(array, kHeaderSize + index * kPointerSize, value);
-  IncrementalMarking::RecordWrite(array, value);
+  array->GetHeap()->incremental_marking()->RecordWrite(array, value);
 }
 
 
 void FixedArray::set_undefined(int index) {
-  ASSERT(map() != Heap::fixed_cow_array_map());
+  ASSERT(map() != HEAP->fixed_cow_array_map());
+  set_undefined(GetHeap(), index);
+}
+
+
+void FixedArray::set_undefined(Heap* heap, int index) {
   ASSERT(index >= 0 && index < this->length());
-  ASSERT(!Heap::InNewSpace(Heap::undefined_value()));
+  ASSERT(!heap->InNewSpace(heap->undefined_value()));
   WRITE_FIELD(this, kHeaderSize + index * kPointerSize,
-              Heap::undefined_value());
+              heap->undefined_value());
 }
 
 
 void FixedArray::set_null(int index) {
-  ASSERT(map() != Heap::fixed_cow_array_map());
+  set_null(GetHeap(), index);
+}
+
+
+void FixedArray::set_null(Heap* heap, int index) {
   ASSERT(index >= 0 && index < this->length());
-  ASSERT(!Heap::InNewSpace(Heap::null_value()));
-  WRITE_FIELD(this, kHeaderSize + index * kPointerSize, Heap::null_value());
+  ASSERT(!heap->InNewSpace(heap->null_value()));
+  WRITE_FIELD(this, kHeaderSize + index * kPointerSize, heap->null_value());
 }
 
 
 void FixedArray::set_the_hole(int index) {
-  ASSERT(map() != Heap::fixed_cow_array_map());
+  ASSERT(map() != HEAP->fixed_cow_array_map());
   ASSERT(index >= 0 && index < this->length());
-  ASSERT(!Heap::InNewSpace(Heap::the_hole_value()));
-  WRITE_FIELD(this, kHeaderSize + index * kPointerSize, Heap::the_hole_value());
+  ASSERT(!HEAP->InNewSpace(HEAP->the_hole_value()));
+  WRITE_FIELD(this,
+              kHeaderSize + index * kPointerSize,
+              GetHeap()->the_hole_value());
 }
 
 
 void FixedArray::set_unchecked(int index, Smi* value) {
   ASSERT(reinterpret_cast<Object*>(value)->IsSmi());
   int offset = kHeaderSize + index * kPointerSize;
   WRITE_FIELD(this, offset, value);
 }
 
 
-void FixedArray::set_unchecked(int index,
+void FixedArray::set_unchecked(Heap* heap,
+                               int index,
                                Object* value,
                                WriteBarrierMode mode) {
   int offset = kHeaderSize + index * kPointerSize;
   WRITE_FIELD(this, offset, value);
-  WRITE_BARRIER(this, offset, value);
+  WRITE_BARRIER(heap, this, offset, value);
 }
 
 
-void FixedArray::set_null_unchecked(int index) {
+void FixedArray::set_null_unchecked(Heap* heap, int index) {
   ASSERT(index >= 0 && index < this->length());
-  ASSERT(!Heap::InNewSpace(Heap::null_value()));
-  WRITE_FIELD(this, kHeaderSize + index * kPointerSize, Heap::null_value());
+  ASSERT(!HEAP->InNewSpace(heap->null_value()));
+  WRITE_FIELD(this, kHeaderSize + index * kPointerSize, heap->null_value());
 }
 
 
 Object** FixedArray::data_start() {
   return HeapObject::RawField(this, kHeaderSize);
 }
 
 
 bool DescriptorArray::IsEmpty() {
-  ASSERT(this == Heap::empty_descriptor_array() ||
-         this->length() > 2);
-  return this == Heap::empty_descriptor_array();
+  ASSERT(this->length() > kFirstIndex ||
+         this == HEAP->empty_descriptor_array());
+  return length() <= kFirstIndex;
 }
 
 
 void DescriptorArray::fast_swap(FixedArray* array, int first, int second) {
   Object* tmp = array->get(first);
   fast_set(array, first, array->get(second));
   fast_set(array, second, tmp);
 }
 
 
 int DescriptorArray::Search(String* name) {
   SLOW_ASSERT(IsSortedNoDuplicates());
 
   // Check for empty descriptor array.
   int nof = number_of_descriptors();
   if (nof == 0) return kNotFound;
 
   // Fast case: do linear search for small arrays.
   const int kMaxElementsForLinearSearch = 8;
   if (StringShape(name).IsSymbol() && nof < kMaxElementsForLinearSearch) {
     return LinearSearch(name, nof);
   }
 
   // Slow case: perform binary search.
   return BinarySearch(name, 0, nof - 1);
 }
 
 
 int DescriptorArray::SearchWithCache(String* name) {
-  int number = DescriptorLookupCache::Lookup(this, name);
+  int number = GetIsolate()->descriptor_lookup_cache()->Lookup(this, name);
   if (number == DescriptorLookupCache::kAbsent) {
     number = Search(name);
-    DescriptorLookupCache::Update(this, name, number);
+    GetIsolate()->descriptor_lookup_cache()->Update(this, name, number);
   }
   return number;
 }
 
 
 String* DescriptorArray::GetKey(int descriptor_number) {
   ASSERT(descriptor_number < number_of_descriptors());
   return String::cast(get(ToKeyIndex(descriptor_number)));
 }
 
@@ skipping 65 matching lines @@
              GetValue(descriptor_number),
              GetDetails(descriptor_number));
 }
 
 
 void DescriptorArray::Set(int descriptor_number, Descriptor* desc) {
   // Range check.
   ASSERT(descriptor_number < number_of_descriptors());
 
   // Make sure none of the elements in desc are in new space.
-  ASSERT(!Heap::InNewSpace(desc->GetKey()));
-  ASSERT(!Heap::InNewSpace(desc->GetValue()));
+  ASSERT(!HEAP->InNewSpace(desc->GetKey()));
+  ASSERT(!HEAP->InNewSpace(desc->GetValue()));
 
   fast_set(this, ToKeyIndex(descriptor_number), desc->GetKey());
   FixedArray* content_array = GetContentArray();
   fast_set(content_array, ToValueIndex(descriptor_number), desc->GetValue());
   fast_set(content_array, ToDetailsIndex(descriptor_number),
            desc->GetDetails().AsSmi());
 }
 
 
 void DescriptorArray::CopyFrom(int index, DescriptorArray* src, int src_index) {
   Descriptor desc;
   src->Get(src_index, &desc);
   Set(index, &desc);
 }
 
 
 void DescriptorArray::Swap(int first, int second) {
   fast_swap(this, ToKeyIndex(first), ToKeyIndex(second));
   FixedArray* content_array = GetContentArray();
   fast_swap(content_array, ToValueIndex(first), ToValueIndex(second));
   fast_swap(content_array, ToDetailsIndex(first),  ToDetailsIndex(second));
 }
 
 
+template<typename Shape, typename Key>
+int HashTable<Shape, Key>::FindEntry(Key key) {
+  return FindEntry(GetIsolate(), key);
+}
+
+
+// Find entry for key otherwise return kNotFound.
+template<typename Shape, typename Key>
+int HashTable<Shape, Key>::FindEntry(Isolate* isolate, Key key) {
+  uint32_t capacity = Capacity();
+  uint32_t entry = FirstProbe(Shape::Hash(key), capacity);
+  uint32_t count = 1;
+  // EnsureCapacity will guarantee the hash table is never full.
+  while (true) {
+    Object* element = KeyAt(entry);
+    if (element == isolate->heap()->undefined_value()) break;  // Empty entry.
+    if (element != isolate->heap()->null_value() &&
+        Shape::IsMatch(key, element)) return entry;
+    entry = NextProbe(entry, count++, capacity);
+  }
+  return kNotFound;
+}
+
+
 bool NumberDictionary::requires_slow_elements() {
   Object* max_index_object = get(kMaxNumberKeyIndex);
   if (!max_index_object->IsSmi()) return false;
   return 0 !=
       (Smi::cast(max_index_object)->value() & kRequiresSlowElementsMask);
 }
 
 uint32_t NumberDictionary::max_number_key() {
   ASSERT(!requires_slow_elements());
   Object* max_index_object = get(kMaxNumberKeyIndex);
@@ skipping 228 matching lines @@
 }
 
 
 Object* ConsString::unchecked_first() {
   return READ_FIELD(this, kFirstOffset);
 }
 
 
 void ConsString::set_first(String* value, WriteBarrierMode mode) {
   WRITE_FIELD(this, kFirstOffset, value);
-  WRITE_BARRIER(this, kFirstOffset, value);
+  WRITE_BARRIER(GetHeap(), this, kFirstOffset, value);
 }
 
 
 String* ConsString::second() {
   return String::cast(READ_FIELD(this, kSecondOffset));
 }
 
 
 Object* ConsString::unchecked_second() {
   return READ_FIELD(this, kSecondOffset);
 }
 
 
 void ConsString::set_second(String* value, WriteBarrierMode mode) {
   WRITE_FIELD(this, kSecondOffset, value);
-  WRITE_BARRIER(this, kSecondOffset, value);
+  WRITE_BARRIER(GetHeap(), this, kSecondOffset, value);
 }
 
 
 ExternalAsciiString::Resource* ExternalAsciiString::resource() {
   return *reinterpret_cast<Resource**>(FIELD_ADDR(this, kResourceOffset));
 }
 
 
 void ExternalAsciiString::set_resource(
     ExternalAsciiString::Resource* resource) {
@@ skipping 15 matching lines @@
 void JSFunctionResultCache::MakeZeroSize() {
   set_finger_index(kEntriesIndex);
   set_size(kEntriesIndex);
 }
 
 
 void JSFunctionResultCache::Clear() {
   int cache_size = size();
   Object** entries_start = RawField(this, OffsetOfElementAt(kEntriesIndex));
   MemsetPointer(entries_start,
-                Heap::the_hole_value(),
+                GetHeap()->the_hole_value(),
                 cache_size - kEntriesIndex);
   MakeZeroSize();
 }
 
 
 int JSFunctionResultCache::size() {
   return Smi::cast(get(kCacheSizeIndex))->value();
 }
 
 
@@ skipping 699 matching lines @@
   HeapObject* code = HeapObject::FromAddress(address - Code::kHeaderSize);
   // GetCodeFromTargetAddress might be called when marking objects during mark
   // sweep. reinterpret_cast is therefore used instead of the more appropriate
   // Code::cast. Code::cast does not work when the object's map is
   // marked.
   Code* result = reinterpret_cast<Code*>(code);
   return result;
 }
 
 
+Heap* Map::heap() {
+  // NOTE: address() helper is not used to save one instruction.
+  Heap* heap = Page::FromAddress(reinterpret_cast<Address>(this))->heap();
+  ASSERT(heap != NULL);
+  ASSERT(heap->isolate() == Isolate::Current());
+  return heap;
+}
+
+
 Object* Code::GetObjectFromEntryAddress(Address location_of_address) {
   return HeapObject::
       FromAddress(Memory::Address_at(location_of_address) - Code::kHeaderSize);
 }
 
 
 Object* Map::prototype() {
   return READ_FIELD(this, kPrototypeOffset);
 }
 
 
 void Map::set_prototype(Object* value, WriteBarrierMode mode) {
   ASSERT(value->IsNull() || value->IsJSObject());
   WRITE_FIELD(this, kPrototypeOffset, value);
-  WRITE_BARRIER(this, kPrototypeOffset, value);
+  WRITE_BARRIER(GetHeap(), this, kPrototypeOffset, value);
 }
 
 
 MaybeObject* Map::GetFastElementsMap() {
   if (has_fast_elements()) return this;
   Object* obj;
   { MaybeObject* maybe_obj = CopyDropTransitions();
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   Map* new_map = Map::cast(obj);
   new_map->set_has_fast_elements(true);
-  Counters::map_slow_to_fast_elements.Increment();
+  COUNTERS->map_slow_to_fast_elements()->Increment();
   return new_map;
 }
 
 
 MaybeObject* Map::GetSlowElementsMap() {
   if (!has_fast_elements()) return this;
   Object* obj;
   { MaybeObject* maybe_obj = CopyDropTransitions();
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   Map* new_map = Map::cast(obj);
   new_map->set_has_fast_elements(false);
-  Counters::map_fast_to_slow_elements.Increment();
+  COUNTERS->map_fast_to_slow_elements()->Increment();
   return new_map;
 }
 
 
 MaybeObject* Map::NewExternalArrayElementsMap() {
   // TODO(danno): Special case empty object map (or most common case)
   // to return a pre-canned pixel array map.
   Object* obj;
   { MaybeObject* maybe_obj = CopyDropTransitions();
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   Map* new_map = Map::cast(obj);
   new_map->set_has_fast_elements(false);
   new_map->set_has_external_array_elements(true);
-  Counters::map_to_external_array_elements.Increment();
+  COUNTERS->map_to_external_array_elements()->Increment();
   return new_map;
 }
 
 
 ACCESSORS(Map, instance_descriptors, DescriptorArray,
           kInstanceDescriptorsOffset)
 ACCESSORS(Map, code_cache, Object, kCodeCacheOffset)
 ACCESSORS(Map, constructor, Object, kConstructorOffset)
 
 ACCESSORS(JSFunction, shared, SharedFunctionInfo, kSharedFunctionInfoOffset)
 ACCESSORS(JSFunction, literals, FixedArray, kLiteralsOffset)
-ACCESSORS(JSFunction, next_function_link, Object, kNextFunctionLinkOffset)
+ACCESSORS_GCSAFE(JSFunction,
+                 next_function_link,
+                 Object,
+                 kNextFunctionLinkOffset)
 
 ACCESSORS(GlobalObject, builtins, JSBuiltinsObject, kBuiltinsOffset)
 ACCESSORS(GlobalObject, global_context, Context, kGlobalContextOffset)
 ACCESSORS(GlobalObject, global_receiver, JSObject, kGlobalReceiverOffset)
 
 ACCESSORS(JSGlobalProxy, context, Object, kContextOffset)
 
 ACCESSORS(AccessorInfo, getter, Object, kGetterOffset)
 ACCESSORS(AccessorInfo, setter, Object, kSetterOffset)
 ACCESSORS(AccessorInfo, data, Object, kDataOffset)
@@ skipping 68 matching lines @@
 ACCESSORS(DebugInfo, code, Code, kPatchedCodeIndex)
 ACCESSORS(DebugInfo, break_points, FixedArray, kBreakPointsStateIndex)
 
 ACCESSORS(BreakPointInfo, code_position, Smi, kCodePositionIndex)
 ACCESSORS(BreakPointInfo, source_position, Smi, kSourcePositionIndex)
 ACCESSORS(BreakPointInfo, statement_position, Smi, kStatementPositionIndex)
 ACCESSORS(BreakPointInfo, break_point_objects, Object, kBreakPointObjectsIndex)
 #endif
 
 ACCESSORS(SharedFunctionInfo, name, Object, kNameOffset)
-ACCESSORS(SharedFunctionInfo, construct_stub, Code, kConstructStubOffset)
-ACCESSORS(SharedFunctionInfo, initial_map, Object, kInitialMapOffset)
+ACCESSORS_GCSAFE(SharedFunctionInfo, construct_stub, Code, kConstructStubOffset)
+ACCESSORS_GCSAFE(SharedFunctionInfo, initial_map, Object, kInitialMapOffset)
 ACCESSORS(SharedFunctionInfo, instance_class_name, Object,
           kInstanceClassNameOffset)
 ACCESSORS(SharedFunctionInfo, function_data, Object, kFunctionDataOffset)
 ACCESSORS(SharedFunctionInfo, script, Object, kScriptOffset)
 ACCESSORS(SharedFunctionInfo, debug_info, Object, kDebugInfoOffset)
 ACCESSORS(SharedFunctionInfo, inferred_name, String, kInferredNameOffset)
 ACCESSORS(SharedFunctionInfo, this_property_assignments, Object,
           kThisPropertyAssignmentsOffset)
 
 BOOL_ACCESSORS(FunctionTemplateInfo, flag, hidden_prototype,
@@ skipping 107 matching lines @@
 void SharedFunctionInfo::set_live_objects_may_exist(bool value) {
   if (value) {
     set_compiler_hints(compiler_hints() | (1 << kLiveObjectsMayExist));
   } else {
     set_compiler_hints(compiler_hints() & ~(1 << kLiveObjectsMayExist));
   }
 }
 
 
 bool SharedFunctionInfo::IsInobjectSlackTrackingInProgress() {
-  return initial_map() != Heap::undefined_value();
+  return initial_map() != HEAP->undefined_value();
 }
 
 
 bool SharedFunctionInfo::optimization_disabled() {
   return BooleanBit::get(compiler_hints(), kOptimizationDisabled);
 }
 
 
 void SharedFunctionInfo::set_optimization_disabled(bool disable) {
   set_compiler_hints(BooleanBit::set(compiler_hints(),
@@ skipping 58 matching lines @@
 }
 
 
 Code* SharedFunctionInfo::unchecked_code() {
   return reinterpret_cast<Code*>(READ_FIELD(this, kCodeOffset));
 }
 
 
 void SharedFunctionInfo::set_code(Code* value, WriteBarrierMode mode) {
   WRITE_FIELD(this, kCodeOffset, value);
-  WRITE_BARRIER(this, kCodeOffset, value);
+  // TODO(gc) ISOLATESMERGE HEAP
+  WRITE_BARRIER(HEAP, this, kCodeOffset, value);
 }
 
 
 SerializedScopeInfo* SharedFunctionInfo::scope_info() {
   return reinterpret_cast<SerializedScopeInfo*>(
       READ_FIELD(this, kScopeInfoOffset));
 }
 
 
 void SharedFunctionInfo::set_scope_info(SerializedScopeInfo* value,
                                         WriteBarrierMode mode) {
   WRITE_FIELD(this, kScopeInfoOffset, reinterpret_cast<Object*>(value));
-  WRITE_BARRIER(this, kScopeInfoOffset, reinterpret_cast<Object*>(value));
+  WRITE_BARRIER(GetHeap(),
+                this,
+                kScopeInfoOffset,
+                reinterpret_cast<Object*>(value));
 }
 
 
 Smi* SharedFunctionInfo::deopt_counter() {
   return reinterpret_cast<Smi*>(READ_FIELD(this, kDeoptCounterOffset));
 }
 
 
 void SharedFunctionInfo::set_deopt_counter(Smi* value) {
   WRITE_FIELD(this, kDeoptCounterOffset, value);
 }
 
 
 bool SharedFunctionInfo::is_compiled() {
-  return code() != Builtins::builtin(Builtins::LazyCompile);
+  return code() !=
+      Isolate::Current()->builtins()->builtin(Builtins::LazyCompile);
 }
 
 
 bool SharedFunctionInfo::IsApiFunction() {
   return function_data()->IsFunctionTemplateInfo();
 }
 
 
 FunctionTemplateInfo* SharedFunctionInfo::get_api_func_data() {
   ASSERT(IsApiFunction());
@@ skipping 39 matching lines @@
       SharedFunctionInfo::kDontAdaptArgumentsSentinel;
 }
 
 
 bool JSFunction::IsOptimized() {
   return code()->kind() == Code::OPTIMIZED_FUNCTION;
 }
 
 
 bool JSFunction::IsMarkedForLazyRecompilation() {
-  return code() == Builtins::builtin(Builtins::LazyRecompile);
+  return code() == GetIsolate()->builtins()->builtin(Builtins::LazyRecompile);
 }
 
 
 Code* JSFunction::code() {
   return Code::cast(unchecked_code());
 }
 
 
 Code* JSFunction::unchecked_code() {
   return reinterpret_cast<Code*>(
       Code::GetObjectFromEntryAddress(FIELD_ADDR(this, kCodeEntryOffset)));
 }
 
 
 void JSFunction::set_code(Code* value) {
   // Skip the write barrier because code is never in new space.
-  ASSERT(!Heap::InNewSpace(value));
+  ASSERT(!HEAP->InNewSpace(value));
   Address entry = value->entry();
   WRITE_INTPTR_FIELD(this, kCodeEntryOffset, reinterpret_cast<intptr_t>(entry));
-  IncrementalMarking::RecordWrite(this, value);
+  GetHeap()->incremental_marking()->RecordWrite(this, value);
 }
 
 
 void JSFunction::ReplaceCode(Code* code) {
   bool was_optimized = IsOptimized();
   bool is_optimized = code->kind() == Code::OPTIMIZED_FUNCTION;
 
   set_code(code);
 
   // Add/remove the function from the list of optimized functions for this
@@ skipping 17 matching lines @@
 }
 
 
 SharedFunctionInfo* JSFunction::unchecked_shared() {
   return reinterpret_cast<SharedFunctionInfo*>(
       READ_FIELD(this, kSharedFunctionInfoOffset));
 }
 
 
 void JSFunction::set_context(Object* value) {
-  ASSERT(value == Heap::undefined_value() || value->IsContext());
+  ASSERT(value->IsUndefined() || value->IsContext());
   WRITE_FIELD(this, kContextOffset, value);
-  WRITE_BARRIER(this, kContextOffset, value);
+  WRITE_BARRIER(GetHeap(), this, kContextOffset, value);
 }
 
 ACCESSORS(JSFunction, prototype_or_initial_map, Object,
           kPrototypeOrInitialMapOffset)
 
 
 Map* JSFunction::initial_map() {
   return Map::cast(prototype_or_initial_map());
 }
 
@@ skipping 34 matching lines @@
   if (map()->has_non_instance_prototype()) return map()->constructor();
   return instance_prototype();
 }
 
 bool JSFunction::should_have_prototype() {
   return map()->function_with_prototype();
 }
 
 
 bool JSFunction::is_compiled() {
-  return code() != Builtins::builtin(Builtins::LazyCompile);
+  return code() != GetIsolate()->builtins()->builtin(Builtins::LazyCompile);
 }
 
 
 int JSFunction::NumberOfLiterals() {
   return literals()->length();
 }
 
 
 Object* JSBuiltinsObject::javascript_builtin(Builtins::JavaScript id) {
   ASSERT(id < kJSBuiltinsCount);  // id is unsigned.
   return READ_FIELD(this, OffsetOfFunctionWithId(id));
 }
 
 
 void JSBuiltinsObject::set_javascript_builtin(Builtins::JavaScript id,
                                               Object* value) {
   ASSERT(id < kJSBuiltinsCount);  // id is unsigned.
   WRITE_FIELD(this, OffsetOfFunctionWithId(id), value);
-  WRITE_BARRIER(this, OffsetOfFunctionWithId(id), value);
+  WRITE_BARRIER(GetHeap(), this, OffsetOfFunctionWithId(id), value);
 }
 
 
 Code* JSBuiltinsObject::javascript_builtin_code(Builtins::JavaScript id) {
   ASSERT(id < kJSBuiltinsCount);  // id is unsigned.
   return Code::cast(READ_FIELD(this, OffsetOfCodeWithId(id)));
 }
 
 
 void JSBuiltinsObject::set_javascript_builtin_code(Builtins::JavaScript id,
                                                    Code* value) {
   ASSERT(id < kJSBuiltinsCount);  // id is unsigned.
   WRITE_FIELD(this, OffsetOfCodeWithId(id), value);
-  ASSERT(!Heap::InNewSpace(value));
+  ASSERT(!HEAP->InNewSpace(value));
 }
 
 
 Address Proxy::proxy() {
   return AddressFrom<Address>(READ_INTPTR_FIELD(this, kProxyOffset));
 }
 
 
 void Proxy::set_proxy(Address value) {
   WRITE_INTPTR_FIELD(this, kProxyOffset, OffsetFrom(value));
@@ skipping 129 matching lines @@
 
 void JSRegExp::SetDataAt(int index, Object* value) {
   ASSERT(TypeTag() != NOT_COMPILED);
   ASSERT(index >= kDataIndex);  // Only implementation data can be set this way.
   FixedArray::cast(data())->set(index, value);
 }
 
 
 JSObject::ElementsKind JSObject::GetElementsKind() {
   if (map()->has_fast_elements()) {
-    ASSERT(elements()->map() == Heap::fixed_array_map() ||
-           elements()->map() == Heap::fixed_cow_array_map());
+    ASSERT(elements()->map() == GetHeap()->fixed_array_map() ||
+           elements()->map() == GetHeap()->fixed_cow_array_map());
     return FAST_ELEMENTS;
   }
   HeapObject* array = elements();
   if (array->IsFixedArray()) {
     // FAST_ELEMENTS or DICTIONARY_ELEMENTS are both stored in a
     // FixedArray, but FAST_ELEMENTS is already handled above.
     ASSERT(array->IsDictionary());
     return DICTIONARY_ELEMENTS;
   }
+  ASSERT(!map()->has_fast_elements());
   if (array->IsExternalArray()) {
     switch (array->map()->instance_type()) {
       case EXTERNAL_BYTE_ARRAY_TYPE:
         return EXTERNAL_BYTE_ELEMENTS;
       case EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE:
         return EXTERNAL_UNSIGNED_BYTE_ELEMENTS;
       case EXTERNAL_SHORT_ARRAY_TYPE:
         return EXTERNAL_SHORT_ELEMENTS;
       case EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE:
         return EXTERNAL_UNSIGNED_SHORT_ELEMENTS;
@@ skipping 65 matching lines @@
 bool JSObject::AllowsSetElementsLength() {
   bool result = elements()->IsFixedArray();
   ASSERT(result == !HasExternalArrayElements());
   return result;
 }
 
 
 MaybeObject* JSObject::EnsureWritableFastElements() {
   ASSERT(HasFastElements());
   FixedArray* elems = FixedArray::cast(elements());
-  if (elems->map() != Heap::fixed_cow_array_map()) return elems;
+  Isolate* isolate = GetIsolate();
+  if (elems->map() != isolate->heap()->fixed_cow_array_map()) return elems;
   Object* writable_elems;
-  { MaybeObject* maybe_writable_elems =
-        Heap::CopyFixedArrayWithMap(elems, Heap::fixed_array_map());
+  { MaybeObject* maybe_writable_elems = isolate->heap()->CopyFixedArrayWithMap(
+      elems, isolate->heap()->fixed_array_map());
     if (!maybe_writable_elems->ToObject(&writable_elems)) {
       return maybe_writable_elems;
     }
   }
   set_elements(FixedArray::cast(writable_elems));
-  Counters::cow_arrays_converted.Increment();
+  isolate->counters()->cow_arrays_converted()->Increment();
   return writable_elems;
 }
 
 
 StringDictionary* JSObject::property_dictionary() {
   ASSERT(!HasFastProperties());
   return StringDictionary::cast(properties());
 }
 
 
@@ skipping 119 matching lines @@
 
 PropertyAttributes JSObject::GetPropertyAttribute(String* key) {
   return GetPropertyAttributeWithReceiver(this, key);
 }
 
 // TODO(504): this may be useful in other places too where JSGlobalProxy
 // is used.
 Object* JSObject::BypassGlobalProxy() {
   if (IsJSGlobalProxy()) {
     Object* proto = GetPrototype();
-    if (proto->IsNull()) return Heap::undefined_value();
+    if (proto->IsNull()) return GetHeap()->undefined_value();
     ASSERT(proto->IsJSGlobalObject());
     return proto;
   }
   return this;
 }
 
 
 bool JSObject::HasHiddenPropertiesObject() {
   ASSERT(!IsJSGlobalProxy());
   return GetPropertyAttributePostInterceptor(this,
-                                             Heap::hidden_symbol(),
+                                             GetHeap()->hidden_symbol(),
                                              false) != ABSENT;
 }
 
 
 Object* JSObject::GetHiddenPropertiesObject() {
   ASSERT(!IsJSGlobalProxy());
   PropertyAttributes attributes;
   // You can't install a getter on a property indexed by the hidden symbol,
   // so we can be sure that GetLocalPropertyPostInterceptor returns a real
   // object.
   Object* result =
       GetLocalPropertyPostInterceptor(this,
-                                      Heap::hidden_symbol(),
+                                      GetHeap()->hidden_symbol(),
                                       &attributes)->ToObjectUnchecked();
   return result;
 }
 
 
 MaybeObject* JSObject::SetHiddenPropertiesObject(Object* hidden_obj) {
   ASSERT(!IsJSGlobalProxy());
-  return SetPropertyPostInterceptor(Heap::hidden_symbol(),
+  return SetPropertyPostInterceptor(GetHeap()->hidden_symbol(),
                                     hidden_obj,
                                     DONT_ENUM,
                                     kNonStrictMode);
 }
 
 
 bool JSObject::HasElement(uint32_t index) {
   return HasElementWithReceiver(this, index);
 }
 
@@ skipping 47 matching lines @@
   ASSERT(!key->IsString() || details.IsDeleted() || details.index() > 0);
   int index = HashTable<Shape, Key>::EntryToIndex(entry);
   AssertNoAllocation no_gc;
   WriteBarrierMode mode = FixedArray::GetWriteBarrierMode(no_gc);
   FixedArray::set(index, key, mode);
   FixedArray::set(index+1, value, mode);
   FixedArray::fast_set(this, index+2, details.AsSmi());
 }
 
 
-void Map::ClearCodeCache() {
+bool NumberDictionaryShape::IsMatch(uint32_t key, Object* other) {
+  ASSERT(other->IsNumber());
+  return key == static_cast<uint32_t>(other->Number());
+}
+
+
+uint32_t NumberDictionaryShape::Hash(uint32_t key) {
+  return ComputeIntegerHash(key);
+}
+
+
+uint32_t NumberDictionaryShape::HashForObject(uint32_t key, Object* other) {
+  ASSERT(other->IsNumber());
+  return ComputeIntegerHash(static_cast<uint32_t>(other->Number()));
+}
+
+
+MaybeObject* NumberDictionaryShape::AsObject(uint32_t key) {
+  return Isolate::Current()->heap()->NumberFromUint32(key);
+}
+
+
+bool StringDictionaryShape::IsMatch(String* key, Object* other) {
+  // We know that all entries in a hash table had their hash keys created.
+  // Use that knowledge to have fast failure.
+  if (key->Hash() != String::cast(other)->Hash()) return false;
+  return key->Equals(String::cast(other));
+}
+
+
+uint32_t StringDictionaryShape::Hash(String* key) {
+  return key->Hash();
+}
+
+
+uint32_t StringDictionaryShape::HashForObject(String* key, Object* other) {
+  return String::cast(other)->Hash();
+}
+
+
+MaybeObject* StringDictionaryShape::AsObject(String* key) {
+  return key;
+}
+
+
+void Map::ClearCodeCache(Heap* heap) {
   // No write barrier is needed since empty_fixed_array is not in new space.
   // Please note this function is used during marking:
   //  - MarkCompactCollector::MarkUnmarkedObject
-  ASSERT(!Heap::InNewSpace(Heap::raw_unchecked_empty_fixed_array()));
-  WRITE_FIELD(this, kCodeCacheOffset, Heap::raw_unchecked_empty_fixed_array());
+  ASSERT(!heap->InNewSpace(heap->raw_unchecked_empty_fixed_array()));
+  WRITE_FIELD(this, kCodeCacheOffset, heap->raw_unchecked_empty_fixed_array());
 }
 
 
 void JSArray::EnsureSize(int required_size) {
   ASSERT(HasFastElements());
   FixedArray* elts = FixedArray::cast(elements());
   const int kArraySizeThatFitsComfortablyInNewSpace = 128;
   if (elts->length() < required_size) {
     // Doubling in size would be overkill, but leave some slack to avoid
     // constantly growing.
     Expand(required_size + (required_size >> 3));
     // It's a performance benefit to keep a frequently used array in new-space.
-  } else if (!Heap::new_space()->Contains(elts) &&
+  } else if (!GetHeap()->new_space()->Contains(elts) &&
              required_size < kArraySizeThatFitsComfortablyInNewSpace) {
     // Expand will allocate a new backing store in new space even if the size
     // we asked for isn't larger than what we had before.
     Expand(required_size);
   }
 }
 
 
 void JSArray::set_length(Smi* length) {
   set_length(static_cast<Object*>(length), SKIP_WRITE_BARRIER);
 }
 
 
 void JSArray::SetContent(FixedArray* storage) {
   set_length(Smi::FromInt(storage->length()));
   set_elements(storage);
 }
 
 
 MaybeObject* FixedArray::Copy() {
   if (length() == 0) return this;
-  return Heap::CopyFixedArray(this);
+  return GetHeap()->CopyFixedArray(this);
+}
+
+
+Relocatable::Relocatable(Isolate* isolate) {
+  ASSERT(isolate == Isolate::Current());
+  isolate_ = isolate;
+  prev_ = isolate->relocatable_top();
+  isolate->set_relocatable_top(this);
+}
+
+
+Relocatable::~Relocatable() {
+  ASSERT(isolate_ == Isolate::Current());
+  ASSERT_EQ(isolate_->relocatable_top(), this);
+  isolate_->set_relocatable_top(prev_);
 }
 
 
 int JSObject::BodyDescriptor::SizeOf(Map* map, HeapObject* object) {
   return map->instance_size();
 }
 
 
 void Proxy::ProxyIterateBody(ObjectVisitor* v) {
   v->VisitExternalReference(
@@ skipping 74 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_