Move representation into HObjectAccess and remove from HLoadNamedField and HStoreNamedField.

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 1074 matching lines @@
   capacity_checker.Else();
 
   environment()->Push(elements);
   capacity_checker.End();
 
   if (is_js_array) {
     HValue* new_length = AddInstruction(
         HAdd::New(zone, context, key, graph_->GetConstant1()));
     new_length->ClearFlag(HValue::kCanOverflow);
 
-    Representation representation = IsFastElementsKind(kind)
-        ? Representation::Smi() : Representation::Tagged();
-    AddStore(object, HObjectAccess::ForArrayLength(), new_length,
-        representation);
+    AddStore(object, HObjectAccess::ForArrayLength(kind), new_length);
   }
 
   length_checker.Else();
   Add<HBoundsCheck>(key, length);
 
   environment()->Push(elements);
   length_checker.End();
 
   return environment()->Pop();
 }
@@ skipping 47 matching lines @@
 
     IfBuilder if_builder(this);
 
     if_builder.IfNot<HCompareObjectEqAndBranch>(elements, empty_fixed_array);
 
     if_builder.Then();
 
     HInstruction* elements_length = AddLoadFixedArrayLength(elements);
 
     HInstruction* array_length = is_jsarray
-        ? AddLoad(object, HObjectAccess::ForArrayLength(),
-                  NULL, Representation::Smi())
+        ? AddLoad(object, HObjectAccess::ForArrayLength(from_kind), NULL)
         : elements_length;
-    array_length->set_type(HType::Smi());
 
     BuildGrowElementsCapacity(object, elements, from_kind, to_kind,
                               array_length, elements_length);
 
     if_builder.End();
   }
 
   AddStore(object, HObjectAccess::ForMap(), map);
 }
 
@@ skipping 27 matching lines @@
   HValue* elements = AddLoadElements(object, mapcheck);
   if (is_store && (fast_elements || fast_smi_only_elements) &&
       store_mode != STORE_NO_TRANSITION_HANDLE_COW) {
     HCheckMaps* check_cow_map = HCheckMaps::New(
         elements, isolate()->factory()->fixed_array_map(), zone, top_info());
     check_cow_map->ClearGVNFlag(kDependsOnElementsKind);
     AddInstruction(check_cow_map);
   }
   HInstruction* length = NULL;
   if (is_js_array) {
-    length = AddLoad(object, HObjectAccess::ForArrayLength(), mapcheck,
-        Representation::Smi());
+    length = AddLoad(object, HObjectAccess::ForArrayLength(elements_kind),
+        mapcheck);
   } else {
     length = AddLoadFixedArrayLength(elements);
   }
   length->set_type(HType::Smi());
   HValue* checked_key = NULL;
   if (IsExternalArrayElementsKind(elements_kind)) {
     if (store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
       NoObservableSideEffectsScope no_effects(this);
       HLoadExternalArrayPointer* external_elements =
           Add<HLoadExternalArrayPointer>(elements);
@@ skipping 95 matching lines @@
 
 void HGraphBuilder::BuildInitializeElementsHeader(HValue* elements,
                                                   ElementsKind kind,
                                                   HValue* capacity) {
   Factory* factory = isolate()->factory();
   Handle<Map> map = IsFastDoubleElementsKind(kind)
       ? factory->fixed_double_array_map()
       : factory->fixed_array_map();
 
   AddStoreMapConstant(elements, map);
-  Representation representation = IsFastElementsKind(kind)
-      ? Representation::Smi() : Representation::Tagged();
-  AddStore(elements, HObjectAccess::ForFixedArrayLength(), capacity,
-      representation);
+  AddStore(elements, HObjectAccess::ForFixedArrayLength(), capacity);
 }
 
 
 HValue* HGraphBuilder::BuildAllocateElementsAndInitializeElementsHeader(
     HValue* context,
     ElementsKind kind,
     HValue* capacity) {
   HValue* new_elements = BuildAllocateElements(context, kind, capacity);
   BuildInitializeElementsHeader(new_elements, kind, capacity);
   return new_elements;
 }
 
 
 HInnerAllocatedObject* HGraphBuilder::BuildJSArrayHeader(HValue* array,
     HValue* array_map,
     AllocationSiteMode mode,
+    ElementsKind elements_kind,
     HValue* allocation_site_payload,
     HValue* length_field) {
 
   AddStore(array, HObjectAccess::ForMap(), array_map);
 
   HConstant* empty_fixed_array =
       Add<HConstant>(isolate()->factory()->empty_fixed_array());
 
   HObjectAccess access = HObjectAccess::ForPropertiesPointer();
   AddStore(array, access, empty_fixed_array);
-  AddStore(array, HObjectAccess::ForArrayLength(), length_field);
+  AddStore(array, HObjectAccess::ForArrayLength(elements_kind), length_field);
 
   if (mode == TRACK_ALLOCATION_SITE) {
     BuildCreateAllocationMemento(array,
                                  JSArray::kSize,
                                  allocation_site_payload);
   }
 
   int elements_location = JSArray::kSize;
   if (mode == TRACK_ALLOCATION_SITE) {
     elements_location += AllocationMemento::kSize;
@@ skipping 86 matching lines @@
 }
 
 
 HLoadNamedField* HGraphBuilder::AddLoadElements(HValue* object,
                                                 HValue* typecheck) {
   return AddLoad(object, HObjectAccess::ForElementsPointer(), typecheck);
 }
 
 
 HLoadNamedField* HGraphBuilder::AddLoadFixedArrayLength(HValue* object) {
-  HLoadNamedField* instr = AddLoad(object, HObjectAccess::ForFixedArrayLength(),
-                                   NULL, Representation::Smi());
-  instr->set_type(HType::Smi());
-  return instr;
+  return AddLoad(object, HObjectAccess::ForFixedArrayLength());
 }
 
 
 HValue* HGraphBuilder::BuildNewElementsCapacity(HValue* context,
                                                 HValue* old_capacity) {
   Zone* zone = this->zone();
   HValue* half_old_capacity =
       AddInstruction(HShr::New(zone, context, old_capacity,
                                graph_->GetConstant1()));
   half_old_capacity->ClearFlag(HValue::kCanOverflow);
@@ skipping 350 matching lines @@
     allocation_site_payload_(NULL),
     constructor_function_(constructor_function) {
 }
 
 
 HValue* HGraphBuilder::JSArrayBuilder::EmitMapCode(HValue* context) {
   if (kind_ == GetInitialFastElementsKind()) {
     // No need for a context lookup if the kind_ matches the initial
     // map, because we can just load the map in that case.
     HObjectAccess access = HObjectAccess::ForPrototypeOrInitialMap();
-    HInstruction* load =
-        builder()->BuildLoadNamedField(constructor_function_,
-                                       access,
-                                       Representation::Tagged());
-    return builder()->AddInstruction(load);
+    return builder()->AddInstruction(
+        builder()->BuildLoadNamedField(constructor_function_, access));
   }
 
   HInstruction* native_context = builder()->BuildGetNativeContext(context);
   HInstruction* index = builder()->Add<HConstant>(
       static_cast<int32_t>(Context::JS_ARRAY_MAPS_INDEX));
 
   HInstruction* map_array = builder()->Add<HLoadKeyed>(
       native_context, index, static_cast<HValue*>(NULL), FAST_ELEMENTS);
 
   HInstruction* kind_index = builder()->Add<HConstant>(kind_);
 
   return builder()->Add<HLoadKeyed>(
       map_array, kind_index, static_cast<HValue*>(NULL), FAST_ELEMENTS);
 }
 
 
 HValue* HGraphBuilder::JSArrayBuilder::EmitInternalMapCode() {
   // Find the map near the constructor function
   HObjectAccess access = HObjectAccess::ForPrototypeOrInitialMap();
   return builder()->AddInstruction(
-      builder()->BuildLoadNamedField(constructor_function_,
-                                     access,
-                                     Representation::Tagged()));
+      builder()->BuildLoadNamedField(constructor_function_, access));
 }
 
 
 HValue* HGraphBuilder::JSArrayBuilder::EstablishAllocationSize(
     HValue* length_node) {
   HValue* context = builder()->environment()->LookupContext();
   ASSERT(length_node != NULL);
 
   int base_size = JSArray::kSize;
   if (mode_ == TRACK_ALLOCATION_SITE) {
@@ skipping 67 matching lines @@
   // Fill in the fields: map, properties, length
   HValue* map;
   if (allocation_site_payload_ == NULL) {
     map = EmitInternalMapCode();
   } else {
     map = EmitMapCode(context);
   }
   elements_location_ = builder()->BuildJSArrayHeader(new_object,
                                                      map,
                                                      mode_,
+                                                     kind_,
                                                      allocation_site_payload_,
                                                      length_field);
 
   // Initialize the elements
   builder()->BuildInitializeElementsHeader(elements_location_, kind_, capacity);
 
   if (fill_with_hole) {
     builder()->BuildFillElementsWithHole(context, elements_location_, kind_,
                                          graph()->GetConstant0(), capacity);
   }
 
   return new_object;
 }
 
 
 HStoreNamedField* HGraphBuilder::AddStore(HValue *object,
                                           HObjectAccess access,
-                                          HValue *val,
-                                          Representation representation) {
-  return Add<HStoreNamedField>(object, access, val, representation);
+                                          HValue *val) {
+  return Add<HStoreNamedField>(object, access, val);
 }
 
 
 HLoadNamedField* HGraphBuilder::AddLoad(HValue *object,
                                         HObjectAccess access,
-                                        HValue *typecheck,
-                                        Representation representation) {
-  return Add<HLoadNamedField>(object, access, typecheck, representation);
+                                        HValue *typecheck) {
+  return Add<HLoadNamedField>(object, access, typecheck);
 }
 
 
 HStoreNamedField* HGraphBuilder::AddStoreMapConstant(HValue *object,
                                                      Handle<Map> map) {
   return Add<HStoreNamedField>(object, HObjectAccess::ForMap(),
                                Add<HConstant>(map));
 }
 
 
@@ skipping 2521 matching lines @@
   if (!is_store) return false;
 
   // 2nd chance: A store into a non-existent field can still be inlined if we
   // have a matching transition and some room left in the object.
   type->LookupTransition(NULL, *name, lookup);
   return lookup->IsTransitionToField(*type) &&
       (type->unused_property_fields() > 0);
 }
 
 
-static Representation ComputeLoadStoreRepresentation(Handle<Map> type,
-                                                     LookupResult* lookup) {
-  if (lookup->IsField()) {
-    return lookup->representation();
-  } else {
-    Map* transition = lookup->GetTransitionMapFromMap(*type);
-    int descriptor = transition->LastAdded();
-    PropertyDetails details =
-        transition->instance_descriptors()->GetDetails(descriptor);
-    return details.representation();
-  }
-}
-
-
 void HOptimizedGraphBuilder::AddCheckMap(HValue* object, Handle<Map> map) {
   BuildCheckHeapObject(object);
   AddInstruction(HCheckMaps::New(object, map, zone(), top_info()));
 }
 
 
 void HOptimizedGraphBuilder::AddCheckMapsWithTransitions(HValue* object,
                                                          Handle<Map> map) {
   BuildCheckHeapObject(object);
   AddInstruction(HCheckMaps::NewWithTransitions(
@@ skipping 31 matching lines @@
       }
       ASSERT(proto->GetPrototype(isolate())->IsNull());
     }
     ASSERT(proto->IsJSObject());
     Add<HCheckPrototypeMaps>(Handle<JSObject>(JSObject::cast(map->prototype())),
                              Handle<JSObject>(JSObject::cast(proto)),
                              zone(), top_info());
   }
 
   HObjectAccess field_access = HObjectAccess::ForField(map, lookup, name);
-  Representation representation = ComputeLoadStoreRepresentation(map, lookup);
   bool transition_to_field = lookup->IsTransitionToField(*map);
 
   HStoreNamedField *instr;
-  if (FLAG_track_double_fields && representation.IsDouble()) {
+  if (FLAG_track_double_fields && field_access.representation().IsDouble()) {
+    HObjectAccess heap_number_access =
+        field_access.WithRepresentation(Representation::Tagged());
     if (transition_to_field) {
       // The store requires a mutable HeapNumber to be allocated.
       NoObservableSideEffectsScope no_side_effects(this);
       HInstruction* heap_number_size = Add<HConstant>(HeapNumber::kSize);
-      HInstruction* double_box = Add<HAllocate>(
+      HInstruction* heap_number = Add<HAllocate>(
           environment()->LookupContext(), heap_number_size,
           HType::HeapNumber(), HAllocate::CAN_ALLOCATE_IN_NEW_SPACE);
-      AddStoreMapConstant(double_box, isolate()->factory()->heap_number_map());
-      AddStore(double_box, HObjectAccess::ForHeapNumberValue(),
-          value, Representation::Double());
-      instr = new(zone()) HStoreNamedField(object, field_access, double_box);
+      AddStoreMapConstant(heap_number, isolate()->factory()->heap_number_map());
+      AddStore(heap_number, HObjectAccess::ForHeapNumberValue(), value);
+      instr = new(zone()) HStoreNamedField(
+          object, heap_number_access, heap_number);
     } else {
       // Already holds a HeapNumber; load the box and write its value field.
-      HInstruction* double_box = AddLoad(object, field_access);
-      double_box->set_type(HType::HeapNumber());
-      instr = new(zone()) HStoreNamedField(double_box,
-          HObjectAccess::ForHeapNumberValue(), value, Representation::Double());
+      HInstruction* heap_number = AddLoad(object, heap_number_access);
+      heap_number->set_type(HType::HeapNumber());
+      instr = new(zone()) HStoreNamedField(heap_number,
+          HObjectAccess::ForHeapNumberValue(), value);
     }
   } else {
-    // This is a non-double store.
-    instr = new(zone()) HStoreNamedField(
-        object, field_access, value, representation);
+    // This is a normal store.
+    instr = new(zone()) HStoreNamedField(object, field_access, value);
   }
 
   if (transition_to_field) {
     Handle<Map> transition(lookup->GetTransitionMapFromMap(*map));
     instr->SetTransition(transition, top_info());
     // TODO(fschneider): Record the new map type of the object in the IR to
     // enable elimination of redundant checks after the transition store.
     instr->SetGVNFlag(kChangesMaps);
   }
   return instr;
@@ skipping 46 matching lines @@
     Property* expr,
     HValue* object,
     SmallMapList* types,
     Handle<String> name) {
   // Use monomorphic load if property lookup results in the same field index
   // for all maps. Requires special map check on the set of all handled maps.
   if (types->length() > kMaxLoadPolymorphism) return NULL;
 
   LookupResult lookup(isolate());
   int count;
-  Representation representation = Representation::None();
   HObjectAccess access = HObjectAccess::ForMap();  // initial value unused.
   for (count = 0; count < types->length(); ++count) {
     Handle<Map> map = types->at(count);
     if (!ComputeLoadStoreField(map, name, &lookup, false)) break;
 
     HObjectAccess new_access = HObjectAccess::ForField(map, &lookup, name);
-    Representation new_representation =
-        ComputeLoadStoreRepresentation(map, &lookup);
 
     if (count == 0) {
       // First time through the loop; set access and representation.
       access = new_access;
-    } else if (!representation.IsCompatibleForLoad(new_representation)) {
+    } else if (!access.representation().IsCompatibleForLoad(
+        new_access.representation())) {
       // Representations did not match.
       break;
     } else if (access.offset() != new_access.offset()) {
       // Offsets did not match.
       break;
     } else if (access.IsInobject() != new_access.IsInobject()) {
       // In-objectness did not match.
       break;
     }
-    representation = representation.generalize(new_representation);
+    access = access.WithRepresentation(
+        access.representation().generalize(new_access.representation()));
   }
 
   if (count == types->length()) {
     // Everything matched; can use monomorphic load.
     BuildCheckHeapObject(object);
     AddInstruction(HCheckMaps::New(object, types, zone()));
-    return BuildLoadNamedField(object, access, representation);
+    return BuildLoadNamedField(object, access);
   }
 
   if (count != 0) return NULL;
 
   // Second chance: the property is on the prototype and all maps have the
   // same prototype.
   Handle<Map> map(types->at(0));
   if (!CanLoadPropertyFromPrototype(map, name, &lookup)) return NULL;
 
   Handle<Object> prototype(map->prototype(), isolate());
   for (count = 1; count < types->length(); ++count) {
     Handle<Map> test_map(types->at(count));
     if (!CanLoadPropertyFromPrototype(test_map, name, &lookup)) return NULL;
     if (test_map->prototype() != *prototype) return NULL;
   }
 
   LookupInPrototypes(map, name, &lookup);
   if (!lookup.IsField()) return NULL;
 
   BuildCheckHeapObject(object);
   AddInstruction(HCheckMaps::New(object, types, zone()));
+
   Handle<JSObject> holder(lookup.holder());
   Handle<Map> holder_map(holder->map());
   AddInstruction(new(zone()) HCheckPrototypeMaps(
       Handle<JSObject>::cast(prototype), holder, zone(), top_info()));
   HValue* holder_value = AddInstruction(new(zone()) HConstant(holder));
   return BuildLoadNamedField(holder_value,
-      HObjectAccess::ForField(holder_map, &lookup, name),
-      ComputeLoadStoreRepresentation(map, &lookup));
+      HObjectAccess::ForField(holder_map, &lookup, name));
 }
 
 
 void HOptimizedGraphBuilder::HandlePolymorphicLoadNamedField(
     Property* expr,
     HValue* object,
     SmallMapList* types,
     Handle<String> name) {
   HInstruction* instr = TryLoadPolymorphicAsMonomorphic(
       expr, object, types, name);
@@ skipping 28 matching lines @@
   int count;
   Representation representation = Representation::None();
   HObjectAccess access = HObjectAccess::ForMap();  // initial value unused.
   for (count = 0; count < types->length(); ++count) {
     Handle<Map> map = types->at(count);
     // Pass false to ignore transitions.
     if (!ComputeLoadStoreField(map, name, &lookup, false)) break;
     ASSERT(!map->is_observed());
 
     HObjectAccess new_access = HObjectAccess::ForField(map, &lookup, name);
-    Representation new_representation =
-        ComputeLoadStoreRepresentation(map, &lookup);
+    Representation new_representation = new_access.representation();
 
     if (count == 0) {
       // First time through the loop; set access and representation.
       access = new_access;
       representation = new_representation;
     } else if (!representation.IsCompatibleForStore(new_representation)) {
       // Representations did not match.
       break;
     } else if (access.offset() != new_access.offset()) {
       // Offsets did not match.
@@ skipping 572 matching lines @@
   HValue* context = environment()->LookupContext();
   HValue* value = environment()->Pop();
   HThrow* instr = Add<HThrow>(context, value);
   instr->set_position(expr->position());
   AddSimulate(expr->id());
   current_block()->FinishExit(new(zone()) HAbnormalExit);
   set_current_block(NULL);
 }
 
 
-HLoadNamedField* HGraphBuilder::BuildLoadNamedField(
-    HValue* object,
-    HObjectAccess access,
-    Representation representation) {
-  bool load_double = false;
-  if (representation.IsDouble()) {
-    representation = Representation::Tagged();
-    load_double = FLAG_track_double_fields;
+HLoadNamedField* HGraphBuilder::BuildLoadNamedField(HValue* object,
+    HObjectAccess access) {
+  if (FLAG_track_double_fields && access.representation().IsDouble()) {
+    // load the heap number
+    HLoadNamedField* heap_number =
+        AddLoad(object, access.WithRepresentation(Representation::Tagged()));
+    heap_number->set_type(HType::HeapNumber());
+    // load the double value from it
+    return new(zone()) HLoadNamedField(heap_number,
+        HObjectAccess::ForHeapNumberValue(), NULL);
   }
-  HLoadNamedField* field =
-      new(zone()) HLoadNamedField(object, access, NULL, representation);
-  if (load_double) {
-    AddInstruction(field);
-    field->set_type(HType::HeapNumber());
-    return new(zone()) HLoadNamedField(field,
-        HObjectAccess::ForHeapNumberValue(), NULL, Representation::Double());
-  }
-  return field;
+  return new(zone()) HLoadNamedField(object, access, NULL);
 }
 
 
 HInstruction* HOptimizedGraphBuilder::BuildLoadNamedGeneric(
     HValue* object,
     Handle<String> name,
     Property* expr) {
   if (expr->IsUninitialized()) {
     AddSoftDeoptimize();
   }
@@ skipping 19 matching lines @@
     Property* expr,
     Handle<Map> map) {
   // Handle a load from a known field.
   ASSERT(!map->is_dictionary_map());
 
   // Handle access to various length properties
   if (name->Equals(isolate()->heap()->length_string())) {
     if (map->instance_type() == JS_ARRAY_TYPE) {
       AddCheckMapsWithTransitions(object, map);
       return new(zone()) HLoadNamedField(object,
-          HObjectAccess::ForArrayLength());
+          HObjectAccess::ForArrayLength(map->elements_kind()));
     }
   }
 
   LookupResult lookup(isolate());
   map->LookupDescriptor(NULL, *name, &lookup);
   if (lookup.IsField()) {
     AddCheckMap(object, map);
     return BuildLoadNamedField(object,
-        HObjectAccess::ForField(map, &lookup, name),
-        ComputeLoadStoreRepresentation(map, &lookup));
+        HObjectAccess::ForField(map, &lookup, name));
   }
 
   // Handle a load of a constant known function.
   if (lookup.IsConstantFunction()) {
     AddCheckMap(object, map);
     Handle<JSFunction> function(lookup.GetConstantFunctionFromMap(*map));
     return new(zone()) HConstant(function);
   }
 
   // Handle a load from a known field somewhere in the prototype chain.
   LookupInPrototypes(map, name, &lookup);
   if (lookup.IsField()) {
     Handle<JSObject> prototype(JSObject::cast(map->prototype()));
     Handle<JSObject> holder(lookup.holder());
     Handle<Map> holder_map(holder->map());
     AddCheckMap(object, map);
     Add<HCheckPrototypeMaps>(prototype, holder, zone(), top_info());
     HValue* holder_value = Add<HConstant>(holder);
     return BuildLoadNamedField(holder_value,
-        HObjectAccess::ForField(holder_map, &lookup, name),
-        ComputeLoadStoreRepresentation(map, &lookup));
+        HObjectAccess::ForField(holder_map, &lookup, name));
   }
 
   // Handle a load of a constant function somewhere in the prototype chain.
   if (lookup.IsConstantFunction()) {
     Handle<JSObject> prototype(JSObject::cast(map->prototype()));
     Handle<JSObject> holder(lookup.holder());
     Handle<Map> holder_map(holder->map());
     AddCheckMap(object, map);
     Add<HCheckPrototypeMaps>(prototype, holder, zone(), top_info());
     Handle<JSFunction> function(lookup.GetConstantFunctionFromMap(*holder_map));
@@ skipping 201 matching lines @@
     set_current_block(this_map);
     HInstruction* checked_key = NULL;
     HInstruction* access = NULL;
     if (IsFastElementsKind(elements_kind)) {
       if (is_store && !IsFastDoubleElementsKind(elements_kind)) {
         AddInstruction(HCheckMaps::New(
             elements, isolate()->factory()->fixed_array_map(),
             zone(), top_info(), mapcompare));
       }
       if (map->IsJSArray()) {
-        HInstruction* length = AddLoad(object, HObjectAccess::ForArrayLength(),
-                                       mapcompare, Representation::Smi());
-        length->set_type(HType::Smi());
+        HInstruction* length = AddLoad(
+            object, HObjectAccess::ForArrayLength(elements_kind), mapcompare);
         checked_key = Add<HBoundsCheck>(key, length);
       } else {
         HInstruction* length = AddLoadFixedArrayLength(elements);
         checked_key = Add<HBoundsCheck>(key, length);
       }
       access = AddFastElementAccess(
           elements, checked_key, val, mapcompare,
           elements_kind, is_store, NEVER_RETURN_HOLE, STANDARD_STORE);
     } else if (IsDictionaryElementsKind(elements_kind)) {
       if (is_store) {
@@ skipping 2771 matching lines @@
   AddStore(object_header, access, properties);
 
   if (boilerplate_object->IsJSArray()) {
     Handle<JSArray> boilerplate_array =
         Handle<JSArray>::cast(boilerplate_object);
     Handle<Object> length_field =
         Handle<Object>(boilerplate_array->length(), isolate());
     HInstruction* length = Add<HConstant>(length_field);
 
     ASSERT(boilerplate_array->length()->IsSmi());
-    Representation representation =
-        IsFastElementsKind(boilerplate_array->GetElementsKind())
-        ? Representation::Smi() : Representation::Tagged();
-    AddStore(object_header, HObjectAccess::ForArrayLength(),
-        length, representation);
+    AddStore(object_header, HObjectAccess::ForArrayLength(
+        boilerplate_array->GetElementsKind()), length);
   }
 
   return result;
 }
 
 
 void HOptimizedGraphBuilder::BuildEmitInObjectProperties(
     Handle<JSObject> boilerplate_object,
     Handle<JSObject> original_boilerplate_object,
     HValue* object_properties,
@@ skipping 45 matching lines @@
         if (data_target != NULL) {
           double_box = Add<HInnerAllocatedObject>(data_target, *data_offset);
           *data_offset += HeapNumber::kSize;
         } else {
           double_box = Add<HInnerAllocatedObject>(target, *offset);
           *offset += HeapNumber::kSize;
         }
         AddStoreMapConstant(double_box,
             isolate()->factory()->heap_number_map());
         AddStore(double_box, HObjectAccess::ForHeapNumberValue(),
-            value_instruction, Representation::Double());
+            value_instruction);
         value_instruction = double_box;
       }
 
       AddStore(object_properties, access, value_instruction);
     }
   }
 
   int inobject_properties = boilerplate_object->map()->inobject_properties();
   HInstruction* value_instruction =
       Add<HConstant>(isolate()->factory()->one_pointer_filler_map());
@@ skipping 1375 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal