Revert of [runtime] Introduce maps for the likely cases of...

Revert of [runtime] Introduce maps for the likely cases of FromPropertyDescriptor. (patchset #1 id:1 of https://codereview.chromium.org/1607943003/ )

Reason for revert:
Predecessor CL suspect for roll breakage: https://codereview.chromium.org/1610563002

Original issue's description:
> [runtime] Introduce maps for the likely cases of FromPropertyDescriptor.
>
> This change improves performance for the common case of
> Object.getOwnPropertyDescriptor by up 3x-4x, where we just
> return a property descriptor object for a regular data or
> accessor property.
>
> R=yangguo@chromium.org
>
> Committed: https://crrev.com/ffa9e82235b20c523ebb1151c6196bc6232296b9
> Cr-Commit-Position: refs/heads/master@{#33398}

TBR=yangguo@chromium.org,bmeurer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1604243002

Cr-Commit-Position: refs/heads/master@{#33403}

src/bootstrapper.cc

@@ -2730,89 +2730,6 @@ bool Genesis::InstallNatives(ContextType context_type) {
 
   InstallBuiltinFunctionIds();
 
-  // Create a map for accessor property descriptors (a variant of JSObject
-  // that predefines four properties get, set, configurable and enumerable).
-  {
-    // AccessorPropertyDescriptor initial map.
-    Handle<Map> map =
-        factory()->NewMap(JS_OBJECT_TYPE, JSAccessorPropertyDescriptor::kSize);
-    // Create the descriptor array for the property descriptor object.
-    Map::EnsureDescriptorSlack(map, 4);
-
-    {  // get
-      DataDescriptor d(factory()->get_string(),
-                       JSAccessorPropertyDescriptor::kGetIndex, NONE,
-                       Representation::Tagged());
-      map->AppendDescriptor(&d);
-    }
-    {  // set
-      DataDescriptor d(factory()->set_string(),
-                       JSAccessorPropertyDescriptor::kSetIndex, NONE,
-                       Representation::Tagged());
-      map->AppendDescriptor(&d);
-    }
-    {  // enumerable
-      DataDescriptor d(factory()->enumerable_string(),
-                       JSAccessorPropertyDescriptor::kEnumerableIndex, NONE,
-                       Representation::Tagged());
-      map->AppendDescriptor(&d);
-    }
-    {  // configurable
-      DataDescriptor d(factory()->configurable_string(),
-                       JSAccessorPropertyDescriptor::kConfigurableIndex, NONE,
-                       Representation::Tagged());
-      map->AppendDescriptor(&d);
-    }
-
-    Map::SetPrototype(map, isolate()->initial_object_prototype());
-    map->SetInObjectProperties(4);
-    map->set_unused_property_fields(0);
-
-    native_context()->set_accessor_property_descriptor_map(*map);
-  }
-
-  // Create a map for data property descriptors (a variant of JSObject
-  // that predefines four properties value, writable, configurable and
-  // enumerable).
-  {
-    // DataPropertyDescriptor initial map.
-    Handle<Map> map =
-        factory()->NewMap(JS_OBJECT_TYPE, JSDataPropertyDescriptor::kSize);
-    // Create the descriptor array for the property descriptor object.
-    Map::EnsureDescriptorSlack(map, 4);
-
-    {  // value
-      DataDescriptor d(factory()->value_string(),
-                       JSDataPropertyDescriptor::kValueIndex, NONE,
-                       Representation::Tagged());
-      map->AppendDescriptor(&d);
-    }
-    {  // writable
-      DataDescriptor d(factory()->writable_string(),
-                       JSDataPropertyDescriptor::kWritableIndex, NONE,
-                       Representation::Tagged());
-      map->AppendDescriptor(&d);
-    }
-    {  // enumerable
-      DataDescriptor d(factory()->enumerable_string(),
-                       JSDataPropertyDescriptor::kEnumerableIndex, NONE,
-                       Representation::Tagged());
-      map->AppendDescriptor(&d);
-    }
-    {  // configurable
-      DataDescriptor d(factory()->configurable_string(),
-                       JSDataPropertyDescriptor::kConfigurableIndex, NONE,
-                       Representation::Tagged());
-      map->AppendDescriptor(&d);
-    }
-
-    Map::SetPrototype(map, isolate()->initial_object_prototype());
-    map->SetInObjectProperties(4);
-    map->set_unused_property_fields(0);
-
-    native_context()->set_data_property_descriptor_map(*map);
-  }
-
   // Create a constructor for RegExp results (a variant of Array that
   // predefines the two properties index and match).
   {

src/contexts.h

@@ -155,8 +155,6 @@ enum BindingFlags {
   V(GLOBAL_PROXY_INDEX, JSObject, global_proxy_object)                         \
   V(EMBEDDER_DATA_INDEX, FixedArray, embedder_data)                            \
   /* Below is alpha-sorted */                                                  \
-  V(ACCESSOR_PROPERTY_DESCRIPTOR_MAP_INDEX, Map,                               \
-    accessor_property_descriptor_map)                                          \
   V(ALLOW_CODE_GEN_FROM_STRINGS_INDEX, Object, allow_code_gen_from_strings)    \
   V(ARRAY_BUFFER_FUN_INDEX, JSFunction, array_buffer_fun)                      \
   V(ARRAY_BUFFER_MAP_INDEX, Map, array_buffer_map)                             \
@@ -173,7 +171,6 @@ enum BindingFlags {
     call_as_constructor_delegate)                                              \
   V(CALL_AS_FUNCTION_DELEGATE_INDEX, JSFunction, call_as_function_delegate)    \
   V(CONTEXT_EXTENSION_FUNCTION_INDEX, JSFunction, context_extension_function)  \
-  V(DATA_PROPERTY_DESCRIPTOR_MAP_INDEX, Map, data_property_descriptor_map)     \
   V(DATA_VIEW_FUN_INDEX, JSFunction, data_view_fun)                            \
   V(DATE_FUNCTION_INDEX, JSFunction, date_function)                            \
   V(ERROR_MESSAGE_FOR_CODE_GEN_FROM_STRINGS_INDEX, Object,                     \

src/objects.h

@@ -2559,52 +2559,6 @@ class JSObject: public JSReceiver {
 };
 
 
-// JSAccessorPropertyDescriptor is just a JSObject with a specific initial
-// map. This initial map adds in-object properties for "get", "set",
-// "enumerable" and "configurable" properties, as assigned by the
-// FromPropertyDescriptor function for regular accessor properties.
-class JSAccessorPropertyDescriptor: public JSObject {
- public:
-  // Offsets of object fields.
-  static const int kGetOffset = JSObject::kHeaderSize;
-  static const int kSetOffset = kGetOffset + kPointerSize;
-  static const int kEnumerableOffset = kSetOffset + kPointerSize;
-  static const int kConfigurableOffset = kEnumerableOffset + kPointerSize;
-  static const int kSize = kConfigurableOffset + kPointerSize;
-  // Indices of in-object properties.
-  static const int kGetIndex = 0;
-  static const int kSetIndex = 1;
-  static const int kEnumerableIndex = 2;
-  static const int kConfigurableIndex = 3;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSAccessorPropertyDescriptor);
-};
-
-
-// JSDataPropertyDescriptor is just a JSObject with a specific initial map.
-// This initial map adds in-object properties for "value", "writable",
-// "enumerable" and "configurable" properties, as assigned by the
-// FromPropertyDescriptor function for regular data properties.
-class JSDataPropertyDescriptor: public JSObject {
- public:
-  // Offsets of object fields.
-  static const int kValueOffset = JSObject::kHeaderSize;
-  static const int kWritableOffset = kValueOffset + kPointerSize;
-  static const int kEnumerableOffset = kWritableOffset + kPointerSize;
-  static const int kConfigurableOffset = kEnumerableOffset + kPointerSize;
-  static const int kSize = kConfigurableOffset + kPointerSize;
-  // Indices of in-object properties.
-  static const int kValueIndex = 0;
-  static const int kWritableIndex = 1;
-  static const int kEnumerableIndex = 2;
-  static const int kConfigurableIndex = 3;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(JSDataPropertyDescriptor);
-};
-
-
 // Common superclass for FixedArrays that allow implementations to share
 // common accessors and some code paths.
 class FixedArrayBase: public HeapObject {

src/property-descriptor.cc

@@ -13,8 +13,6 @@
 namespace v8 {
 namespace internal {
 
-namespace {
-
 // Helper function for ToPropertyDescriptor. Comments describe steps for
 // "enumerable", other properties are handled the same way.
 // Returns false if an exception was thrown.
@@ -103,51 +101,19 @@ bool ToPropertyDescriptorFastPath(Isolate* isolate, Handle<Object> obj,
 }
 
 
-void CreateDataProperty(Isolate* isolate, Handle<JSObject> object,
-                        Handle<String> name, Handle<Object> value) {
+static void CreateDataProperty(Isolate* isolate, Handle<JSObject> object,
+                               Handle<String> name, Handle<Object> value) {
   LookupIterator it(object, name, LookupIterator::OWN_SKIP_INTERCEPTOR);
   Maybe<bool> result = JSObject::CreateDataProperty(&it, value);
   CHECK(result.IsJust() && result.FromJust());
 }
 
-}  // namespace
-
 
 // ES6 6.2.4.4 "FromPropertyDescriptor"
 Handle<Object> PropertyDescriptor::ToObject(Isolate* isolate) {
   DCHECK(!(PropertyDescriptor::IsAccessorDescriptor(this) &&
            PropertyDescriptor::IsDataDescriptor(this)));
   Factory* factory = isolate->factory();
-  if (IsRegularAccessorProperty()) {
-    // Fast case for regular accessor properties.
-    Handle<JSObject> result = factory->NewJSObjectFromMap(
-        isolate->accessor_property_descriptor_map());
-    result->InObjectPropertyAtPut(JSAccessorPropertyDescriptor::kGetIndex,
-                                  *get());
-    result->InObjectPropertyAtPut(JSAccessorPropertyDescriptor::kSetIndex,
-                                  *set());
-    result->InObjectPropertyAtPut(
-        JSAccessorPropertyDescriptor::kEnumerableIndex,
-        isolate->heap()->ToBoolean(enumerable()));
-    result->InObjectPropertyAtPut(
-        JSAccessorPropertyDescriptor::kConfigurableIndex,
-        isolate->heap()->ToBoolean(configurable()));
-    return result;
-  }
-  if (IsRegularDataProperty()) {
-    // Fast case for regular data properties.
-    Handle<JSObject> result =
-        factory->NewJSObjectFromMap(isolate->data_property_descriptor_map());
-    result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kValueIndex,
-                                  *value());
-    result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kWritableIndex,
-                                  isolate->heap()->ToBoolean(writable()));
-    result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kEnumerableIndex,
-                                  isolate->heap()->ToBoolean(enumerable()));
-    result->InObjectPropertyAtPut(JSDataPropertyDescriptor::kConfigurableIndex,
-                                  isolate->heap()->ToBoolean(configurable()));
-    return result;
-  }
   Handle<JSObject> result = factory->NewJSObject(isolate->object_function());
   if (has_value()) {
     CreateDataProperty(isolate, result, factory->value_string(), value());

src/property-descriptor.h

@@ -57,16 +57,6 @@ class PropertyDescriptor {
            !has_value() && !has_get() && !has_set();
   }
 
-  bool IsRegularAccessorProperty() const {
-    return has_configurable() && has_enumerable() && !has_value() &&
-           !has_writable() && has_get() && has_set();
-  }
-
-  bool IsRegularDataProperty() const {
-    return has_configurable() && has_enumerable() && has_value() &&
-           has_writable() && !has_get() && !has_set();
-  }
-
   bool enumerable() const { return enumerable_; }
   void set_enumerable(bool enumerable) {
     enumerable_ = enumerable;