Addressed perf regression in Browsermark2.0 array blur test

src/hydrogen.cc

 // Copyright 2013 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 5102 matching lines @@
     AllocationSiteUsageContext usage_context(isolate(), site, false);
     usage_context.EnterNewScope();
     literal = BuildFastLiteral(boilerplate_object, &usage_context);
     usage_context.ExitScope(site, boilerplate_object);
   } else {
     NoObservableSideEffectsScope no_effects(this);
     // Boilerplate already exists and constant elements are never accessed,
     // pass an empty fixed array to the runtime function instead.
     Handle<FixedArray> constants = isolate()->factory()->empty_fixed_array();
     int literal_index = expr->literal_index();
+    int flags = expr->depth() == 1
+        ? ArrayLiteral::kShallowElements
+        : ArrayLiteral::kNoFlags;
+    flags |= ArrayLiteral::kDisableMementos;
 
     Add<HPushArgument>(Add<HConstant>(literals));
     Add<HPushArgument>(Add<HConstant>(literal_index));
     Add<HPushArgument>(Add<HConstant>(constants));
+    Add<HPushArgument>(Add<HConstant>(flags));
 
     // TODO(mvstanton): Consider a flag to turn off creation of any
     // AllocationMementos for this call: we are in crankshaft and should have
     // learned enough about transition behavior to stop emitting mementos.
     Runtime::FunctionId function_id = Runtime::kCreateArrayLiteral;
     literal = Add<HCallRuntime>(isolate()->factory()->empty_string(),
                                 Runtime::FunctionForId(function_id),
-                                3);
+                                4);
 
     // De-opt if elements kind changed from boilerplate_elements_kind.
     Handle<Map> map = Handle<Map>(boilerplate_object->map(), isolate());
     literal = Add<HCheckMaps>(literal, map, top_info());
   }
 
   // The array is expected in the bailout environment during computation
   // of the property values and is the value of the entire expression.
   Push(literal);
   // The literal index is on the stack, too.
@@ skipping 4049 matching lines @@
       return New<HConstant>(
           function_state()->compilation_info()->closure());
   } else {
       return New<HThisFunction>();
   }
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildFastLiteral(
     Handle<JSObject> boilerplate_object,
-    AllocationSiteContext* site_context) {
+    AllocationSiteUsageContext* site_context) {
   NoObservableSideEffectsScope no_effects(this);
   InstanceType instance_type = boilerplate_object->map()->instance_type();
   ASSERT(instance_type == JS_ARRAY_TYPE || instance_type == JS_OBJECT_TYPE);
 
   HType type = instance_type == JS_ARRAY_TYPE
       ? HType::JSArray() : HType::JSObject();
   HValue* object_size_constant = Add<HConstant>(
       boilerplate_object->map()->instance_size());
   HInstruction* object = Add<HAllocate>(object_size_constant, type,
       isolate()->heap()->GetPretenureMode(), instance_type);
@@ skipping 72 matching lines @@
     object_elements = Add<HConstant>(elements_field);
   }
   Add<HStoreNamedField>(object, HObjectAccess::ForElementsPointer(),
       object_elements);
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitInObjectProperties(
     Handle<JSObject> boilerplate_object,
     HInstruction* object,
-    AllocationSiteContext* site_context) {
+    AllocationSiteUsageContext* site_context) {
   Handle<DescriptorArray> descriptors(
       boilerplate_object->map()->instance_descriptors());
   int limit = boilerplate_object->map()->NumberOfOwnDescriptors();
 
   int copied_fields = 0;
   for (int i = 0; i < limit; i++) {
     PropertyDetails details = descriptors->GetDetails(i);
     if (details.type() != FIELD) continue;
     copied_fields++;
     int index = descriptors->GetFieldIndex(i);
@@ skipping 51 matching lines @@
     HObjectAccess access = HObjectAccess::ForJSObjectOffset(property_offset);
     Add<HStoreNamedField>(object, access, value_instruction);
   }
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitElements(
     Handle<JSObject> boilerplate_object,
     Handle<FixedArrayBase> elements,
     HValue* object_elements,
-    AllocationSiteContext* site_context) {
+    AllocationSiteUsageContext* site_context) {
   ElementsKind kind = boilerplate_object->map()->elements_kind();
   int elements_length = elements->length();
   HValue* object_elements_length = Add<HConstant>(elements_length);
   BuildInitializeElementsHeader(object_elements, kind, object_elements_length);
 
   // Copy elements backing store content.
   if (elements->IsFixedDoubleArray()) {
     BuildEmitFixedDoubleArray(elements, kind, object_elements);
   } else if (elements->IsFixedArray()) {
     BuildEmitFixedArray(elements, kind, object_elements,
@@ skipping 20 matching lines @@
                                            value_instruction, kind);
     store->SetFlag(HValue::kAllowUndefinedAsNaN);
   }
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitFixedArray(
     Handle<FixedArrayBase> elements,
     ElementsKind kind,
     HValue* object_elements,
-    AllocationSiteContext* site_context) {
+    AllocationSiteUsageContext* site_context) {
   HInstruction* boilerplate_elements = Add<HConstant>(elements);
   int elements_length = elements->length();
   Handle<FixedArray> fast_elements = Handle<FixedArray>::cast(elements);
   for (int i = 0; i < elements_length; i++) {
     Handle<Object> value(fast_elements->get(i), isolate());
     HValue* key_constant = Add<HConstant>(i);
     if (value->IsJSObject()) {
       Handle<JSObject> value_object = Handle<JSObject>::cast(value);
       Handle<AllocationSite> current_site = site_context->EnterNewScope();
       HInstruction* result =
@@ skipping 1249 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal