Simplify feedback vector creation and store in SharedFunctionInfo.

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 25 matching lines @@
 #include "type-info.h"
 
 #include "ic-inl.h"
 #include "objects-inl.h"
 
 namespace v8 {
 namespace internal {
 
 
 TypeFeedbackOracle::TypeFeedbackOracle(Handle<Code> code,
+                                       Handle<FixedArray> feedback_vector,
                                        Handle<Context> native_context,
                                        Zone* zone)
     : native_context_(native_context),
       zone_(zone) {
-  Object* raw_info = code->type_feedback_info();
-  if (raw_info->IsTypeFeedbackInfo()) {
-    feedback_vector_ = Handle<FixedArray>(TypeFeedbackInfo::cast(raw_info)->
-                                          feedback_vector());
-  }
-
   BuildDictionary(code);
   ASSERT(dictionary_->IsDictionary());
+  // We make a copy of the feedback vector because a GC could clear
+  // the type feedback info contained therein.
+  // TODO(mvstanton): revisit the decision to copy when we weakly
+  // traverse the feedback vector at GC time.
+  feedback_vector_ = isolate()->factory()->CopyFixedArray(feedback_vector);
 }
 
 
 static uint32_t IdToKey(TypeFeedbackId ast_id) {
   return static_cast<uint32_t>(ast_id.ToInt());
 }
 
 
 Handle<Object> TypeFeedbackOracle::GetInfo(TypeFeedbackId ast_id) {
   int entry = dictionary_->FindEntry(IdToKey(ast_id));
@@ skipping 61 matching lines @@
 bool TypeFeedbackOracle::CallNewIsMonomorphic(int slot) {
   Handle<Object> info = GetInfo(slot);
   return FLAG_pretenuring_call_new
       ? info->IsJSFunction()
       : info->IsAllocationSite() || info->IsJSFunction();
 }
 
 
 byte TypeFeedbackOracle::ForInType(int feedback_vector_slot) {
   Handle<Object> value = GetInfo(feedback_vector_slot);
-  return value->IsSmi() &&
-      Smi::cast(*value)->value() == TypeFeedbackInfo::kForInFastCaseMarker
-          ? ForInStatement::FAST_FOR_IN : ForInStatement::SLOW_FOR_IN;
+  return value.is_identical_to(
+      TypeFeedbackInfo::UninitializedSentinel(isolate()))
+      ? ForInStatement::FAST_FOR_IN : ForInStatement::SLOW_FOR_IN;
 }
 
 
 KeyedAccessStoreMode TypeFeedbackOracle::GetStoreMode(
     TypeFeedbackId ast_id) {
   Handle<Object> maybe_code = GetInfo(ast_id);
   if (maybe_code->IsCode()) {
     Handle<Code> code = Handle<Code>::cast(maybe_code);
     if (code->kind() == Code::KEYED_STORE_IC) {
       return KeyedStoreIC::GetKeyedAccessStoreMode(code->extra_ic_state());
@@ skipping 341 matching lines @@
          UnseededNumberDictionary::kNotFound);
   // Dictionary has been allocated with sufficient size for all elements.
   DisallowHeapAllocation no_need_to_resize_dictionary;
   HandleScope scope(isolate());
   USE(UnseededNumberDictionary::AtNumberPut(
       dictionary_, IdToKey(ast_id), handle(target, isolate())));
 }
 
 
 } }  // namespace v8::internal