Insert explicit deoptimization for named loads that have "uninitialized" type feedback.

src/type-info.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 59 matching lines @@
 
 
 Handle<Object> TypeFeedbackOracle::GetInfo(unsigned ast_id) {
   int entry = dictionary_->FindEntry(ast_id);
   return entry != UnseededNumberDictionary::kNotFound
       ? Handle<Object>(dictionary_->ValueAt(entry))
       : Handle<Object>::cast(isolate_->factory()->undefined_value());
 }
 
 
+bool TypeFeedbackOracle::LoadIsUninitialized(Property* expr) {
+  Handle<Object> map_or_code = GetInfo(expr->id());
+  if (map_or_code->IsMap()) return false;
+  if (map_or_code->IsCode()) {
+    Handle<Code> code = Handle<Code>::cast(map_or_code);
+    return code->is_inline_cache_stub() && code->ic_state() == UNINITIALIZED;
+  }
+  return false;
+}
+
+
 bool TypeFeedbackOracle::LoadIsMonomorphicNormal(Property* expr) {
   Handle<Object> map_or_code = GetInfo(expr->id());
   if (map_or_code->IsMap()) return true;
   if (map_or_code->IsCode()) {
     Handle<Code> code = Handle<Code>::cast(map_or_code);
     return code->is_keyed_load_stub() &&
         code->ic_state() == MONOMORPHIC &&
         Code::ExtractTypeFromFlags(code->flags()) == NORMAL &&
         code->FindFirstMap() != NULL &&
         !CanRetainOtherContext(code->FindFirstMap(), *global_context_);
@@ skipping 552 matching lines @@
             SetInfo(ast_id, Smi::FromInt(target->check_type()));
           } else {
             Object* map = target->FindFirstMap();
             if (map == NULL) {
               SetInfo(ast_id, static_cast<Object*>(target));
             } else if (!CanRetainOtherContext(Map::cast(map),
                                               *global_context_)) {
               SetInfo(ast_id, map);
             }
           }
-        } else if (target->ic_state() == MEGAMORPHIC) {
+        } else {
           SetInfo(ast_id, target);
         }
         break;
 
       case Code::KEYED_LOAD_IC:
       case Code::KEYED_STORE_IC:
         if (target->ic_state() == MONOMORPHIC ||
             target->ic_state() == MEGAMORPHIC) {
           SetInfo(ast_id, target);
         }
@@ skipping 37 matching lines @@
   USE(maybe_result);
 #ifdef DEBUG
   Object* result = NULL;
   // Dictionary has been allocated with sufficient size for all elements.
   ASSERT(maybe_result->ToObject(&result));
   ASSERT(*dictionary_ == result);
 #endif
 }
 
 } }  // namespace v8::internal