Remake of the load elimination fix made earlier (r18884).

src/objects-inl.h

 // Copyright 2012 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 1950 matching lines @@
     WRITE_FIELD(this, offset, value);
     WRITE_BARRIER(GetHeap(), this, offset, value);
   } else {
     ASSERT(index < properties()->length());
     properties()->set(index, value);
   }
 }
 
 
 int JSObject::GetInObjectPropertyOffset(int index) {
-  // Adjust for the number of properties stored in the object.
-  index -= map()->inobject_properties();
-  ASSERT(index < 0);
-  return map()->instance_size() + (index * kPointerSize);
+  return map()->GetInObjectPropertyOffset(index);
 }
 
 
 Object* JSObject::InObjectPropertyAt(int index) {
-  // Adjust for the number of properties stored in the object.
-  index -= map()->inobject_properties();
-  ASSERT(index < 0);
-  int offset = map()->instance_size() + (index * kPointerSize);
+  int offset = GetInObjectPropertyOffset(index);
   return READ_FIELD(this, offset);
 }
 
 
 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);
+  int offset = GetInObjectPropertyOffset(index);
   WRITE_FIELD(this, offset, value);
   CONDITIONAL_WRITE_BARRIER(GetHeap(), this, offset, value, mode);
   return value;
 }
 
 
 
 void JSObject::InitializeBody(Map* map,
                               Object* pre_allocated_value,
                               Object* filler_value) {
@@ skipping 1780 matching lines @@
 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();
+  ASSERT(index < 0);
+  return instance_size() + (index * kPointerSize);
+}
+
+
+int Map::GetInObjectPropertyIndex(int offset) {
+  ASSERT(offset >= 0);
+  return (offset - instance_size()) / kPointerSize + inobject_properties();
+}
+
+
 int HeapObject::SizeFromMap(Map* map) {
   int instance_size = map->instance_size();
   if (instance_size != kVariableSizeSentinel) return instance_size;
   // Only inline the most frequent cases.
   int instance_type = static_cast<int>(map->instance_type());
   if (instance_type == FIXED_ARRAY_TYPE) {
     return FixedArray::BodyDescriptor::SizeOf(map, this);
   }
   if (instance_type == ASCII_STRING_TYPE ||
       instance_type == ASCII_INTERNALIZED_STRING_TYPE) {
@@ skipping 2983 matching lines @@
 #undef READ_UINT32_FIELD
 #undef WRITE_UINT32_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_