Use mutable heapnumbers to store doubles in fields.

src/runtime.cc

 // 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 216 matching lines @@
   // slow properties mode for now. We don't go in the map cache because
   // maps with constant functions can't be shared if the functions are
   // not the same (which is the common case).
   bool is_result_from_cache = false;
   Handle<Map> map = has_function_literal
       ? Handle<Map>(context->object_function()->initial_map())
       : ComputeObjectLiteralMap(context,
                                 constant_properties,
                                 &is_result_from_cache);
 
-  Handle<JSObject> boilerplate =
-      isolate->factory()->NewJSObjectFromMap(
-          map, isolate->heap()->GetPretenureMode());
+  Factory* factory = isolate->factory();

[danno, 2013/05/07 13:04:47]

Don't need this change.

[Toon Verwaest, 2013/05/07 15:08:52]

Done.

+  Handle<JSObject> boilerplate = factory->NewJSObjectFromMap(
+      map, isolate->heap()->GetPretenureMode());
 
   // Normalize the elements of the boilerplate to save space if needed.
   if (!should_have_fast_elements) JSObject::NormalizeElements(boilerplate);
 
   // Add the constant properties to the boilerplate.
   int length = constant_properties->length();
   bool should_transform =
       !is_result_from_cache && boilerplate->HasFastProperties();
   if (should_transform || has_function_literal) {
     // Normalize the properties of object to avoid n^2 behavior
@@ skipping 13144 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal