[ic] LoadGlobalIC caches PropertyCells in the feedback vector.

src/runtime/runtime-object.cc

 // Copyright 2014 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/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/debug/debug.h"
 #include "src/isolate-inl.h"
@@ skipping 256 matching lines @@
   // Conservative upper limit to prevent fuzz tests from going OOM.
   RUNTIME_ASSERT(properties <= 100000);
   if (object->HasFastProperties() && !object->IsJSGlobalProxy()) {
     JSObject::NormalizeProperties(object, KEEP_INOBJECT_PROPERTIES, properties,
                                   "OptimizeForAdding");
   }
   return *object;
 }
 
 
-RUNTIME_FUNCTION(Runtime_LoadGlobalViaContext) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(1, args.length());
-  CONVERT_SMI_ARG_CHECKED(slot, 0);
-
-  // Go up context chain to the script context.
-  Handle<Context> script_context(isolate->context()->script_context(), isolate);
-  DCHECK(script_context->IsScriptContext());
-  DCHECK(script_context->get(slot)->IsPropertyCell());
-
-  // Lookup the named property on the global object.
-  Handle<ScopeInfo> scope_info(script_context->scope_info(), isolate);
-  Handle<Name> name(scope_info->ContextSlotName(slot), isolate);
-  Handle<JSGlobalObject> global_object(script_context->global_object(),
-                                       isolate);
-  LookupIterator it(global_object, name, global_object, LookupIterator::OWN);
-
-  // Switch to fast mode only if there is a data property and it's not on
-  // a hidden prototype.
-  if (it.state() == LookupIterator::DATA &&
-      it.GetHolder<Object>().is_identical_to(global_object)) {
-    // Now update the cell in the script context.
-    Handle<PropertyCell> cell = it.GetPropertyCell();
-    script_context->set(slot, *cell);
-  } else {
-    // This is not a fast case, so keep this access in a slow mode.
-    // Store empty_property_cell here to release the outdated property cell.
-    script_context->set(slot, isolate->heap()->empty_property_cell());
-  }
-
-  RETURN_RESULT_OR_FAILURE(isolate, Object::GetProperty(&it));
-}
-
-
 namespace {
 
 Object* StoreGlobalViaContext(Isolate* isolate, int slot, Handle<Object> value,
                               LanguageMode language_mode) {
   // Go up context chain to the script context.
   Handle<Context> script_context(isolate->context()->script_context(), isolate);
   DCHECK(script_context->IsScriptContext());
   DCHECK(script_context->get(slot)->IsPropertyCell());
 
   // Lookup the named property on the global object.
@@ skipping 683 matching lines @@
       isolate, o, key, &success, LookupIterator::OWN);
   if (!success) return isolate->heap()->exception();
   MAYBE_RETURN(
       JSReceiver::CreateDataProperty(&it, value, Object::THROW_ON_ERROR),
       isolate->heap()->exception());
   return *value;
 }
 
 }  // namespace internal
 }  // namespace v8