[heap] Remove size specializations in static object visitors.

src/objects-body-descriptors-inl.h

 // Copyright 2015 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_BODY_DESCRIPTORS_INL_H_
 #define V8_OBJECTS_BODY_DESCRIPTORS_INL_H_
 
 #include "src/assembler-inl.h"
 #include "src/objects-body-descriptors.h"
 #include "src/transitions.h"
@@ skipping 113 matching lines @@
   static inline void IterateBody(HeapObject* obj, int object_size) {
     Heap* heap = obj->GetHeap();
     IterateBodyImpl<StaticVisitor>(heap, obj, kStartOffset, object_size);
   }
 
   static inline int SizeOf(Map* map, HeapObject* object) {
     return map->instance_size();
   }
 };
 
+class JSObject::FastBodyDescriptor final : public BodyDescriptorBase {

[ulan, 2017/03/27 11:23:24]

This is the same as FlexibleBodyDescriptor except for SizeOf, which is much
faster here.

+ public:
+  static const int kStartOffset = JSReceiver::kPropertiesOffset;
+
+  static bool IsValidSlot(HeapObject* obj, int offset) {
+    return offset >= kStartOffset;
+  }
+
+  template <typename ObjectVisitor>
+  static inline void IterateBody(HeapObject* obj, int object_size,
+                                 ObjectVisitor* v) {
+    IteratePointers(obj, kStartOffset, object_size, v);
+  }
+
+  template <typename StaticVisitor>
+  static inline void IterateBody(HeapObject* obj, int object_size) {
+    Heap* heap = obj->GetHeap();
+    IteratePointers<StaticVisitor>(heap, obj, kStartOffset, object_size);
+  }
+
+  static inline int SizeOf(Map* map, HeapObject* object) {
+    return map->instance_size();
+  }
+};
+
 // Iterates the function object according to the visiting policy.
 template <JSFunction::BodyVisitingPolicy body_visiting_policy>
 class JSFunction::BodyDescriptorImpl final : public BodyDescriptorBase {
  public:
   STATIC_ASSERT(kNonWeakFieldsEndOffset == kCodeEntryOffset);
   STATIC_ASSERT(kCodeEntryOffset + kPointerSize == kNextFunctionLinkOffset);
   STATIC_ASSERT(kNextFunctionLinkOffset + kPointerSize == kSize);
 
   static bool IsValidSlot(HeapObject* obj, int offset) {
     if (offset < kSize) return true;
@@ skipping 481 matching lines @@
 
 template <typename ObjectVisitor>
 void HeapObject::IterateBodyFast(InstanceType type, int object_size,
                                  ObjectVisitor* v) {
   BodyDescriptorApply<CallIterateBody, void>(type, this, object_size, v);
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_BODY_DESCRIPTORS_INL_H_