Additional work to get array literal allocation tracking working, even with --always-opt

src/ic.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 1834 matching lines @@
     StrictModeFlag strict_mode,
     KeyedAccessGrowMode grow_mode) {
   // Collect MONOMORPHIC stubs for all target_receiver_maps.
   CodeHandleList handler_ics(receiver_maps->length());
   MapHandleList transitioned_maps(receiver_maps->length());
   for (int i = 0; i < receiver_maps->length(); ++i) {
     Handle<Map> receiver_map(receiver_maps->at(i));
     Handle<Code> cached_stub;
     Handle<Map> transitioned_map =
         receiver_map->FindTransitionedMap(receiver_maps);
+
+    // TODO(mvstanton): we should set the transitioned map to always be

[Toon Verwaest, 2013/01/16 10:53:42]

Should probably clarify that we are talking about pessimistic elements
transitions.

[mvstanton, 2013/01/16 13:01:56]

Done.

+    // null, and quit doing transitions on key stores. Right now though
+    // if I do this there are some serious performance issues.
+
     if (!transitioned_map.is_null()) {
       cached_stub = ElementsTransitionAndStoreStub(
           receiver_map->elements_kind(),  // original elements_kind
           transitioned_map->elements_kind(),
           receiver_map->instance_type() == JS_ARRAY_TYPE,  // is_js_array
           strict_mode, grow_mode).GetCode();
     } else {
       cached_stub = ComputeMonomorphicStubWithoutMapCheck(receiver_map,
                                                           strict_mode,
                                                           grow_mode);
@@ skipping 995 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal