- Added fast case for extending the JSObject properties storage....

src/handles.cc

 // Copyright 2006-2008 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 68 matching lines @@
     func->set_initial_map(*new_initial_map);
   }
 }
 
 
 void SetPrototypeProperty(Handle<JSFunction> func, Handle<JSObject> value) {
   CALL_HEAP_FUNCTION_VOID(func->SetPrototype(*value));
 }
 
 
+static int ExpectedNofPropertiesFromEstimate(int estimate) {
+  // TODO(1231235): We need dynamic feedback to estimate the number
+  // of expected properties in an object. The static hack below
+  // is barely a solution.
+  if (estimate == 0) return 4;
+  return estimate + 2;
+}
+
+
 void SetExpectedNofPropertiesFromEstimate(Handle<SharedFunctionInfo> shared,
                                           int estimate) {
-  // TODO(1231235): We need dynamic feedback to estimate the number
-  // of expected properties in an object. The static hack below
-  // is barely a solution.
-  shared->set_expected_nof_properties(estimate + 2);
+  shared->set_expected_nof_properties(
+      ExpectedNofPropertiesFromEstimate(estimate));
 }
 
 
 void SetExpectedNofPropertiesFromEstimate(Handle<JSFunction> func,
                                           int estimate) {
-  // TODO(1231235): We need dynamic feedback to estimate the number
-  // of expected properties in an object. The static hack below
-  // is barely a solution.
-  SetExpectedNofProperties(func, estimate + 2);
+  SetExpectedNofProperties(
+      func, ExpectedNofPropertiesFromEstimate(estimate));
 }
 
 
 void NormalizeProperties(Handle<JSObject> object) {
   CALL_HEAP_FUNCTION_VOID(object->NormalizeProperties());
 }
 
 
 void NormalizeElements(Handle<JSObject> object) {
   CALL_HEAP_FUNCTION_VOID(object->NormalizeElements());
@@ skipping 430 matching lines @@
                Handle<Context> security_context) {
   Handle<FixedArray> arr = Factory::NewFixedArray(4);
   arr->set(0, Smi::FromInt(index));
   arr->set(1, *compile_context);  // Compile in this context
   arr->set(2, *function_context);  // Set function context to this
   arr->set(3, *security_context);  // Receiver for call
   fun->shared()->set_lazy_load_data(*arr);
 }
 
 } }  // namespace v8::internal