Recover performance of array buffer view field accesses in ICs

src/accessors.cc

Index: src/accessors.cc
diff --git a/src/accessors.cc b/src/accessors.cc
index df981dc151a2362ed071f8be673efdf5d7189efb..ba977bc8dd989efa0256e42d60edcad085616132 100644
--- a/src/accessors.cc
+++ b/src/accessors.cc
@@ -93,6 +93,39 @@ bool Accessors::IsJSObjectFieldAccessor(Handle<Map> map, Handle<Name> name,
 }
 
 
+bool Accessors::IsJSArrayBufferViewFieldAccessor(Handle<Map> map,
+                                                 Handle<Name> name,
+                                                 int* object_offset) {
+  Isolate* isolate = name->GetIsolate();
+
+  switch (map->instance_type()) {
+    case JS_TYPED_ARRAY_TYPE:
+      // %TypedArray%.prototype is non-configurable, and so are the following
+      // named properties on %TypedArray%.prototype, so we can directly inline
+      // the field-load for typed array maps that still use their
+      // %TypedArray%.prototype.
+      if (JSFunction::cast(map->GetConstructor())->prototype() !=
+          map->prototype()) {
+        return false;
+      }
+      return CheckForName(name, isolate->factory()->length_string(),
+                          JSTypedArray::kLengthOffset, object_offset) ||
+             CheckForName(name, isolate->factory()->byte_length_string(),
+                          JSTypedArray::kByteLengthOffset, object_offset) ||
+             CheckForName(name, isolate->factory()->byte_offset_string(),
+                          JSTypedArray::kByteOffsetOffset, object_offset);
+
+    case JS_DATA_VIEW_TYPE:
+      return CheckForName(name, isolate->factory()->byte_length_string(),
+                          JSDataView::kByteLengthOffset, object_offset) ||
+             CheckForName(name, isolate->factory()->byte_offset_string(),
+                          JSDataView::kByteOffsetOffset, object_offset);
+    default:
+      return false;
+  }
+}
+
+
 bool SetPropertyOnInstanceIfInherited(
     Isolate* isolate, const v8::PropertyCallbackInfo<void>& info,
     v8::Local<v8::Name> name, Handle<Object> value) {