Remove unused byte from Map::instance_sizes field.

src/objects-inl.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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 2130 matching lines @@
 void JSObject::InitializeBody(Map* map,
                               Object* pre_allocated_value,
                               Object* filler_value) {
   DCHECK(!filler_value->IsHeapObject() ||
          !GetHeap()->InNewSpace(filler_value));
   DCHECK(!pre_allocated_value->IsHeapObject() ||
          !GetHeap()->InNewSpace(pre_allocated_value));
   int size = map->instance_size();
   int offset = kHeaderSize;
   if (filler_value != pre_allocated_value) {
-    int pre_allocated = map->pre_allocated_property_fields();
+    int pre_allocated =
+        map->inobject_properties() - map->unused_property_fields();
     DCHECK(pre_allocated * kPointerSize + kHeaderSize <= size);
     for (int i = 0; i < pre_allocated; i++) {
       WRITE_FIELD(this, offset, pre_allocated_value);
       offset += kPointerSize;
     }
   }
   while (offset < size) {
     WRITE_FIELD(this, offset, filler_value);
     offset += kPointerSize;
   }
@@ skipping 1914 matching lines @@
   return NOBARRIER_READ_BYTE_FIELD(
       this, kInstanceSizeOffset) << kPointerSizeLog2;
 }
 
 
 int Map::inobject_properties() {
   return READ_BYTE_FIELD(this, kInObjectPropertiesOffset);
 }
 
 
-int Map::pre_allocated_property_fields() {
-  return READ_BYTE_FIELD(this, kPreAllocatedPropertyFieldsOffset);
-}
-
-
 int Map::GetInObjectPropertyOffset(int index) {
   // Adjust for the number of properties stored in the object.
   index -= inobject_properties();
   DCHECK(index <= 0);
   return instance_size() + (index * kPointerSize);
 }
 
 
 Handle<Map> Map::CopyInstallDescriptorsForTesting(
     Handle<Map> map, int new_descriptor, Handle<DescriptorArray> descriptors,
@@ skipping 53 matching lines @@
       this, kInstanceSizeOffset, static_cast<byte>(value));
 }
 
 
 void Map::set_inobject_properties(int value) {
   DCHECK(0 <= value && value < 256);
   WRITE_BYTE_FIELD(this, kInObjectPropertiesOffset, static_cast<byte>(value));
 }
 
 
-void Map::set_pre_allocated_property_fields(int value) {
-  DCHECK(0 <= value && value < 256);
-  WRITE_BYTE_FIELD(this,
-                   kPreAllocatedPropertyFieldsOffset,
-                   static_cast<byte>(value));
-}
+void Map::clear_unused() { WRITE_BYTE_FIELD(this, kUnusedOffset, 0); }
 
 
 InstanceType Map::instance_type() {
   return static_cast<InstanceType>(READ_BYTE_FIELD(this, kInstanceTypeOffset));
 }
 
 
 void Map::set_instance_type(InstanceType value) {
   WRITE_BYTE_FIELD(this, kInstanceTypeOffset, value);
 }
@@ skipping 3135 matching lines @@
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_