Promoting elements transitions to their own field.

src/objects-printer.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 255 matching lines @@
           break;
         }
         case CONSTANT_FUNCTION:
           descs->GetConstantFunction(i)->ShortPrint(out);
           PrintF(out, " (constant function)\n");
           break;
         case CALLBACKS:
           descs->GetCallbacksObject(i)->ShortPrint(out);
           PrintF(out, " (callback)\n");
           break;
-        case ELEMENTS_TRANSITION: {
-          PrintF(out, "(elements transition to ");
-          Object* descriptor_contents = descs->GetValue(i);
-          if (descriptor_contents->IsMap()) {
-            Map* map = Map::cast(descriptor_contents);
-            PrintElementsKind(out, map->elements_kind());
-          } else {
-            FixedArray* map_array = FixedArray::cast(descriptor_contents);
-            for (int i = 0; i < map_array->length(); ++i) {
-              Map* map = Map::cast(map_array->get(i));
-              if (i != 0) {
-                PrintF(out, ", ");
-              }
-              PrintElementsKind(out, map->elements_kind());
-            }
-          }
-          PrintF(out, ")\n");
-          break;
-        }
         case MAP_TRANSITION:
           PrintF(out, "(map transition)\n");
           break;
         case CONSTANT_TRANSITION:
           PrintF(out, "(constant transition)\n");
           break;
         case NULL_DESCRIPTOR:
           PrintF(out, "(null descriptor)\n");
           break;
         case NORMAL:  // only in slow mode
@@ skipping 126 matching lines @@
 
 void JSObject::JSObjectPrint(FILE* out) {
   PrintF(out, "%p: [JSObject]\n", reinterpret_cast<void*>(this));
   PrintF(out, " - map = %p [", reinterpret_cast<void*>(map()));
   // Don't call GetElementsKind, its validation code can cause the printer to
   // fail when debugging.
   PrintElementsKind(out, this->map()->elements_kind());
   PrintF(out,
          "]\n - prototype = %p\n",
          reinterpret_cast<void*>(GetPrototype()));
+  PrintF(out,
+         " - elements transition to = %p\n",
+         reinterpret_cast<void*>(map()->elements_transition_map()));
   PrintF(out, " {\n");
   PrintProperties(out);
   PrintElements(out);
   PrintF(out, " }\n");
 }
 
 
 void JSModule::JSModulePrint(FILE* out) {
   HeapObject::PrintHeader(out, "JSModule");
   PrintF(out, " - map = 0x%p\n", reinterpret_cast<void*>(map()));
@@ skipping 582 matching lines @@
     desc.Print(out);
   }
   PrintF(out, "\n");
 }
 
 
 #endif  // OBJECT_PRINT
 
 
 } }  // namespace v8::internal