Remove GetAttributes from the mix to avoid another virtual dispatch.

src/elements.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/arguments.h"
 #include "src/conversions.h"
 #include "src/elements.h"
 #include "src/messages.h"
@@ skipping 567 matching lines @@
     ElementsAccessorSubclass::ValidateContents(holder, length);
   }
 
   void Validate(Handle<JSObject> holder) final {
     DisallowHeapAllocation no_gc;
     ElementsAccessorSubclass::ValidateImpl(holder);
   }
 
   static bool HasElementImpl(Handle<JSObject> holder, uint32_t key,
                              Handle<FixedArrayBase> backing_store) {
-    return ElementsAccessorSubclass::GetAttributesImpl(
-               *holder, key, *backing_store) != ABSENT;
+    return ElementsAccessorSubclass::GetIndexForKeyImpl(*holder, *backing_store,

[Igor Sheludko, 2015/06/11 14:59:45]

Do we need HasElementImpl() given that now GetIndexForKeyImpl() does all the
dirty job?

[Toon Verwaest, 2015/06/11 15:16:06]

Done.

+                                                        key) != kMaxUInt32;
   }
 
   virtual bool HasElement(Handle<JSObject> holder, uint32_t key,
                           Handle<FixedArrayBase> backing_store) final {
     return ElementsAccessorSubclass::HasElementImpl(holder, key, backing_store);
   }
 
   virtual Handle<Object> Get(Handle<JSObject> holder, uint32_t key,
                              Handle<FixedArrayBase> backing_store) final {
     if (!IsExternalArrayElementsKind(ElementsTraits::Kind) &&
@@ skipping 26 matching lines @@
 
   static Handle<Object> SetImpl(Handle<JSObject> obj, uint32_t key,
                                 Handle<FixedArrayBase> backing_store,
                                 Handle<Object> value) {
     CHECK(key <
           ElementsAccessorSubclass::GetCapacityImpl(*obj, *backing_store));
     return BackingStore::SetValue(
         obj, Handle<BackingStore>::cast(backing_store), key, value);
   }
 
-  virtual PropertyAttributes GetAttributes(
-      JSObject* holder, uint32_t key, FixedArrayBase* backing_store) final {
-    return ElementsAccessorSubclass::GetAttributesImpl(holder, key,
-                                                       backing_store);
-  }
-
-  static PropertyAttributes GetAttributesImpl(JSObject* obj, uint32_t key,
-                                              FixedArrayBase* backing_store) {
-    if (key >= ElementsAccessorSubclass::GetCapacityImpl(obj, backing_store)) {
-      return ABSENT;
-    }
-    return BackingStore::cast(backing_store)->is_the_hole(key) ? ABSENT : NONE;
-  }
-
   virtual MaybeHandle<AccessorPair> GetAccessorPair(
       Handle<JSObject> holder, uint32_t key,
       Handle<FixedArrayBase> backing_store) final {
     return ElementsAccessorSubclass::GetAccessorPairImpl(holder, key,
                                                          backing_store);
   }
 
   static MaybeHandle<AccessorPair> GetAccessorPairImpl(
       Handle<JSObject> obj, uint32_t key,
       Handle<FixedArrayBase> backing_store) {
@@ skipping 175 matching lines @@
   static uint32_t GetKeyForIndexImpl(FixedArrayBase* backing_store,
                                      uint32_t index) {
     return index;
   }
 
   virtual uint32_t GetKeyForIndex(FixedArrayBase* backing_store,
                                   uint32_t index) final {
     return ElementsAccessorSubclass::GetKeyForIndexImpl(backing_store, index);
   }
 
-  static uint32_t GetIndexForKeyImpl(FixedArrayBase* backing_store,
+  static uint32_t GetIndexForKeyImpl(JSObject* holder,
+                                     FixedArrayBase* backing_store,
                                      uint32_t key) {
-    return key;
+    return key < ElementsAccessorSubclass::GetCapacityImpl(holder,
+                                                           backing_store) &&
+                   !BackingStore::cast(backing_store)->is_the_hole(key)
+               ? key
+               : kMaxUInt32;
   }
 
-  virtual uint32_t GetIndexForKey(FixedArrayBase* backing_store,
+  virtual uint32_t GetIndexForKey(JSObject* holder,
+                                  FixedArrayBase* backing_store,
                                   uint32_t key) final {
-    return ElementsAccessorSubclass::GetIndexForKeyImpl(backing_store, key);
+    return ElementsAccessorSubclass::GetIndexForKeyImpl(holder, backing_store,
+                                                        key);
   }
 
   static PropertyDetails GetDetailsImpl(FixedArrayBase* backing_store,
                                         uint32_t index) {
     return PropertyDetails(NONE, DATA, 0, PropertyCellType::kNoCell);
   }
 
   virtual PropertyDetails GetDetails(FixedArrayBase* backing_store,
                                      uint32_t index) final {
     return ElementsAccessorSubclass::GetDetailsImpl(backing_store, index);
@@ skipping 124 matching lines @@
         }
       }
     }
   }
 
   virtual void Delete(Handle<JSObject> obj, uint32_t key,
                       LanguageMode language_mode) final {
     DeleteCommon(obj, key, language_mode);
   }
 
-  static bool HasElementImpl(
-      Handle<JSObject> holder,
-      uint32_t key,
-      Handle<FixedArrayBase> backing_store) {
-    if (key >= static_cast<uint32_t>(backing_store->length())) {
-      return false;
-    }
-    return !Handle<BackingStore>::cast(backing_store)->is_the_hole(key);
-  }
-
   static bool HasIndexImpl(FixedArrayBase* backing_store, uint32_t index) {
     return !BackingStore::cast(backing_store)->is_the_hole(index);
   }
 
   static void ValidateContents(Handle<JSObject> holder, int length) {
 #if DEBUG
     Isolate* isolate = holder->GetIsolate();
     HandleScope scope(isolate);
     Handle<FixedArrayBase> elements(holder->elements(), isolate);
     Map* map = elements->map();
@@ skipping 269 matching lines @@
 
   static Handle<Object> GetImpl(Handle<JSObject> obj, uint32_t key,
                                 Handle<FixedArrayBase> backing_store) {
     if (key < AccessorClass::GetCapacityImpl(*obj, *backing_store)) {
       return BackingStore::get(Handle<BackingStore>::cast(backing_store), key);
     } else {
       return backing_store->GetIsolate()->factory()->undefined_value();
     }
   }
 
-  static PropertyAttributes GetAttributesImpl(JSObject* obj, uint32_t key,
-                                              FixedArrayBase* backing_store) {
-    return key < AccessorClass::GetCapacityImpl(obj, backing_store)
-               ? DONT_DELETE
-               : ABSENT;
-  }
-
   static PropertyDetails GetDetailsImpl(FixedArrayBase* backing_store,
                                         uint32_t index) {
     return PropertyDetails(DONT_DELETE, DATA, 0, PropertyCellType::kNoCell);
   }
 
   MUST_USE_RESULT static MaybeHandle<Object> SetLengthImpl(
       Handle<JSObject> obj,
       Handle<Object> length,
       Handle<FixedArrayBase> backing_store) {
     // External arrays do not support changing their length.
     UNREACHABLE();
     return obj;
   }
 
   virtual void Delete(Handle<JSObject> obj, uint32_t key,
                       LanguageMode language_mode) final {
     // External arrays always ignore deletes.
   }
 
-  static bool HasElementImpl(Handle<JSObject> holder, uint32_t key,
-                             Handle<FixedArrayBase> backing_store) {
-    uint32_t capacity = AccessorClass::GetCapacityImpl(*holder, *backing_store);
-    return key < capacity;
+  static uint32_t GetIndexForKeyImpl(JSObject* holder,
+                                     FixedArrayBase* backing_store,
+                                     uint32_t key) {
+    return key < AccessorClass::GetCapacityImpl(holder, backing_store)
+               ? key
+               : kMaxUInt32;
   }
 
   static uint32_t GetCapacityImpl(JSObject* holder,
                                   FixedArrayBase* backing_store) {
     JSArrayBufferView* view = JSArrayBufferView::cast(holder);
     if (view->WasNeutered()) return 0;
     return backing_store->length();
   }
 };
 
@@ skipping 142 matching lines @@
                                 Handle<FixedArrayBase> store,
                                 Handle<Object> value) {
     Handle<SeededNumberDictionary> backing_store =
         Handle<SeededNumberDictionary>::cast(store);
     int entry = backing_store->FindEntry(key);
     DCHECK_NE(SeededNumberDictionary::kNotFound, entry);
     backing_store->ValueAtPut(entry, *value);
     return value;
   }
 
-  static PropertyAttributes GetAttributesImpl(JSObject* obj, uint32_t key,
-                                              FixedArrayBase* backing_store) {
-    SeededNumberDictionary* dictionary =
-        SeededNumberDictionary::cast(backing_store);
-    int entry = dictionary->FindEntry(key);
-    if (entry != SeededNumberDictionary::kNotFound) {
-      return dictionary->DetailsAt(entry).attributes();
-    }
-    return ABSENT;
-  }
-
   static MaybeHandle<AccessorPair> GetAccessorPairImpl(
       Handle<JSObject> obj, uint32_t key, Handle<FixedArrayBase> store) {
     Handle<SeededNumberDictionary> backing_store =
         Handle<SeededNumberDictionary>::cast(store);
     int entry = backing_store->FindEntry(key);
     if (entry != SeededNumberDictionary::kNotFound &&
         backing_store->DetailsAt(entry).type() == ACCESSOR_CONSTANT &&
         backing_store->ValueAt(entry)->IsAccessorPair()) {
       return handle(AccessorPair::cast(backing_store->ValueAt(entry)));
     }
     return MaybeHandle<AccessorPair>();
   }
 
-  static bool HasElementImpl(Handle<JSObject> holder, uint32_t key,
-                             Handle<FixedArrayBase> store) {
-    Handle<SeededNumberDictionary> backing_store =
-        Handle<SeededNumberDictionary>::cast(store);
-    return backing_store->FindEntry(key) != SeededNumberDictionary::kNotFound;
-  }
-
   static bool HasIndexImpl(FixedArrayBase* store, uint32_t index) {
     DisallowHeapAllocation no_gc;
     SeededNumberDictionary* dict = SeededNumberDictionary::cast(store);
     Object* key = dict->KeyAt(index);
     return !key->IsTheHole();
   }
 
   static uint32_t GetKeyForIndexImpl(FixedArrayBase* store, uint32_t index) {
     DisallowHeapAllocation no_gc;
     SeededNumberDictionary* dict = SeededNumberDictionary::cast(store);
     Object* key = dict->KeyAt(index);
     return Smi::cast(key)->value();
   }
 
-  static uint32_t GetIndexForKeyImpl(FixedArrayBase* store, uint32_t key) {
+  static uint32_t GetIndexForKeyImpl(JSObject* holder, FixedArrayBase* store,
+                                     uint32_t key) {
     DisallowHeapAllocation no_gc;
     SeededNumberDictionary* dict = SeededNumberDictionary::cast(store);
     int entry = dict->FindEntry(key);
-    if (entry == SeededNumberDictionary::kNotFound) {
-      return kMaxUInt32;
-    }
-    return static_cast<uint32_t>(entry);
+    return entry == SeededNumberDictionary::kNotFound
+               ? kMaxUInt32
+               : static_cast<uint32_t>(entry);
   }
 
   static PropertyDetails GetDetailsImpl(FixedArrayBase* backing_store,
                                         uint32_t index) {
     return SeededNumberDictionary::cast(backing_store)->DetailsAt(index);
   }
 };
 
 
 class SloppyArgumentsElementsAccessor : public ElementsAccessorBase<
@@ skipping 50 matching lines @@
       int context_index = Smi::cast(probe)->value();
       DCHECK(!context->get(context_index)->IsTheHole());
       context->set(context_index, *value);
       return value;
     }
     Handle<FixedArray> arguments(FixedArray::cast(parameter_map->get(1)));
     return ElementsAccessor::ForArray(arguments)
         ->Set(obj, key, arguments, value);
   }
 
-  static PropertyAttributes GetAttributesImpl(JSObject* obj, uint32_t key,
-                                              FixedArrayBase* backing_store) {
-    FixedArray* parameter_map = FixedArray::cast(backing_store);
-    Object* probe = GetParameterMapArg(parameter_map, key);
-    if (!probe->IsTheHole()) {
-      return NONE;
-    } else {
-      // If not aliased, check the arguments.
-      FixedArray* arguments = FixedArray::cast(parameter_map->get(1));
-      return ElementsAccessor::ForArray(arguments)
-          ->GetAttributes(obj, key, arguments);
-    }
-  }
-
   static MaybeHandle<AccessorPair> GetAccessorPairImpl(
       Handle<JSObject> obj, uint32_t key, Handle<FixedArrayBase> parameters) {
     Handle<FixedArray> parameter_map = Handle<FixedArray>::cast(parameters);
     Handle<Object> probe(GetParameterMapArg(*parameter_map, key),
                          obj->GetIsolate());
     if (!probe->IsTheHole()) {
       return MaybeHandle<AccessorPair>();
     } else {
       // If not aliased, check the arguments.
       Handle<FixedArray> arguments(FixedArray::cast(parameter_map->get(1)));
@@ skipping 64 matching lines @@
   static uint32_t GetKeyForIndexImpl(FixedArrayBase* parameters,
                                      uint32_t index) {
     FixedArray* parameter_map = FixedArray::cast(parameters);
     uint32_t length = parameter_map->length() - 2;
     if (index < length) return index;
 
     FixedArray* arguments = FixedArray::cast(parameter_map->get(1));
     return ForArray(arguments)->GetKeyForIndex(arguments, index - length);
   }
 
-  static uint32_t GetIndexForKeyImpl(FixedArrayBase* parameters, uint32_t key) {
+  static uint32_t GetIndexForKeyImpl(JSObject* holder,
+                                     FixedArrayBase* parameters, uint32_t key) {
     FixedArray* parameter_map = FixedArray::cast(parameters);
     Object* probe = GetParameterMapArg(parameter_map, key);
     if (!probe->IsTheHole()) return key;
 
-    uint32_t length = parameter_map->length() - 2;
     FixedArray* arguments = FixedArray::cast(parameter_map->get(1));
-    return length +
-           ElementsAccessor::ForArray(arguments)
-               ->GetIndexForKey(arguments, key);
+    uint32_t index = ElementsAccessor::ForArray(arguments)
+                         ->GetIndexForKey(holder, arguments, key);
+    if (index == kMaxUInt32) return index;
+    return (parameter_map->length() - 2) + index;
   }
 
   static PropertyDetails GetDetailsImpl(FixedArrayBase* parameters,
                                         uint32_t index) {
     FixedArray* parameter_map = FixedArray::cast(parameters);
     uint32_t length = parameter_map->length() - 2;
     if (index < length) {
       return PropertyDetails(NONE, DATA, 0, PropertyCellType::kNoCell);
     }
     index -= length;
@@ skipping 200 matching lines @@
       break;
   }
 
   array->set_elements(*elms);
   array->set_length(Smi::FromInt(number_of_elements));
   return array;
 }
 
 }  // namespace internal
 }  // namespace v8