Use hash map to look for objects in the root array when serializing.

src/compiler.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/compiler.h"
 
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 1218 matching lines @@
       compilation_cache->PutScript(source, context, result);
       // TODO(yangguo): Issue 3628
       // With block scoping, top-level variables may resolve to a global,
       // context, which makes the code context-dependent.
       if (FLAG_serialize_toplevel && !FLAG_harmony_scoping &&
           compile_options == ScriptCompiler::kProduceCodeCache) {
         HistogramTimerScope histogram_timer(
             isolate->counters()->compile_serialize());
         *cached_data = CodeSerializer::Serialize(isolate, result, source);
         if (FLAG_profile_deserialization) {
-          PrintF("[Compiling and serializing %d bytes took %0.3f ms]\n",
-                 (*cached_data)->length(), timer.Elapsed().InMillisecondsF());
+          PrintF("[Compiling and serializing took %0.3f ms]\n",
+                 timer.Elapsed().InMillisecondsF());
         }
       }
     }
 
     if (result.is_null()) isolate->ReportPendingMessages();
   } else if (result->ic_age() != isolate->heap()->global_ic_age()) {
     result->ResetForNewContext(isolate->heap()->global_ic_age());
   }
   return result;
 }
@@ skipping 204 matching lines @@
   AllowHandleDereference allow_deref;
   bool tracing_on = info()->IsStub()
       ? FLAG_trace_hydrogen_stubs
       : (FLAG_trace_hydrogen &&
          info()->closure()->PassesFilter(FLAG_trace_hydrogen_filter));
   return (tracing_on &&
       base::OS::StrChr(const_cast<char*>(FLAG_trace_phase), name_[0]) != NULL);
 }
 
 } }  // namespace v8::internal