Track computed literal properties.

src/objects.h

 // Copyright 2012 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 1042 matching lines @@
 
   // Filler objects (fillers and free space objects).
   inline bool IsFiller();
 
   // Extract the number.
   inline double Number();
   inline bool IsNaN();
   bool ToInt32(int32_t* value);
   bool ToUint32(uint32_t* value);
 
-  inline Representation OptimalRepresentation() {
-    if (FLAG_track_fields && IsSmi()) {
+  // Indicates to OptimalRepresentation what kind of value it is being invoked
+  // on. The representation of REAL_VALUEs is entirely dependent on the value.
+  // PLACEHOLDER_VALUEs have Representation::None(), so the actual
+  // representation can be determined later on. FORCE_TAGGED is used when
+  // initializing a field that will later be used for any kind of value without
+  // following the regular property assignments paths that will lead to
+  // generlization.
+  enum ValueType {
+    REAL_VALUE,
+    PLACEHOLDER_VALUE,
+    FORCE_TAGGED
+  };
+
+  inline Representation OptimalRepresentation(ValueType type = REAL_VALUE) {
+    if (!FLAG_track_fields) return Representation::Tagged();
+    if (type == PLACEHOLDER_VALUE) return Representation::None();
+    if (type == FORCE_TAGGED) return Representation::Tagged();
+    if (IsSmi()) {
       return Representation::Smi();
     } else if (FLAG_track_double_fields && IsHeapNumber()) {
       return Representation::Double();
-    } else if (FLAG_track_heap_object_fields && !IsUndefined()) {
-      // Don't track undefined as heapobject because it's also used as temporary
-      // value for computed fields that may turn out to be Smi. That combination
-      // will go tagged, so go tagged immediately.
-      // TODO(verwaest): Change once we track computed boilerplate fields.
+    } else if (FLAG_track_heap_object_fields) {
       ASSERT(IsHeapObject());
       return Representation::HeapObject();
     } else {
       return Representation::Tagged();
     }
   }
 
   inline bool FitsRepresentation(Representation representation) {
-    if (FLAG_track_fields && representation.IsSmi()) {
+    if (FLAG_track_fields && representation.IsNone()) {
+      return false;
+    } else if (FLAG_track_fields && representation.IsSmi()) {
       return IsSmi();
     } else if (FLAG_track_double_fields && representation.IsDouble()) {
       return IsNumber();
     } else if (FLAG_track_heap_object_fields && representation.IsHeapObject()) {
       return IsHeapObject();
     }
     return true;
   }
 
   inline MaybeObject* AllocateNewStorageFor(Heap* heap,
@@ skipping 728 matching lines @@
       Name* name,
       Object* value,
       PropertyAttributes attributes,
       StrictModeFlag strict_mode,
       ExtensibilityCheck extensibility_check);
 
   static Handle<Object> SetLocalPropertyIgnoreAttributes(
       Handle<JSObject> object,
       Handle<Name> key,
       Handle<Object> value,
-      PropertyAttributes attributes);
+      PropertyAttributes attributes,
+      ValueType value_type = REAL_VALUE);
 
   static inline Handle<String> ExpectedTransitionKey(Handle<Map> map);
   static inline Handle<Map> ExpectedTransitionTarget(Handle<Map> map);
 
   // Try to follow an existing transition to a field with attributes NONE. The
   // return value indicates whether the transition was successful.
   static inline Handle<Map> FindTransitionToField(Handle<Map> map,
                                                   Handle<Name> key);
 
   inline int LastAddedFieldIndex();
 
   // Extend the receiver with a single fast property appeared first in the
   // passed map. This also extends the property backing store if necessary.
   static void AllocateStorageForMap(Handle<JSObject> object, Handle<Map> map);
   inline MUST_USE_RESULT MaybeObject* AllocateStorageForMap(Map* map);
 
   static void MigrateInstance(Handle<JSObject> instance);
   inline MUST_USE_RESULT MaybeObject* MigrateInstance();
 
   static Handle<Object> TryMigrateInstance(Handle<JSObject> instance);
   inline MUST_USE_RESULT MaybeObject* TryMigrateInstance();
 
   // Can cause GC.
   MUST_USE_RESULT MaybeObject* SetLocalPropertyIgnoreAttributes(
       Name* key,
       Object* value,
-      PropertyAttributes attributes);
+      PropertyAttributes attributes,
+      ValueType value_type = REAL_VALUE);
 
   // Retrieve a value in a normalized object given a lookup result.
   // Handles the special representation of JS global objects.
   Object* GetNormalizedProperty(LookupResult* result);
 
   // Sets the property value in a normalized object given a lookup result.
   // Handles the special representation of JS global objects.
   Object* SetNormalizedProperty(LookupResult* result, Object* value);
 
   // Sets the property value in a normalized object given (key, value, details).
@@ skipping 341 matching lines @@
   MUST_USE_RESULT MaybeObject* MigrateToMap(Map* new_map);
   MUST_USE_RESULT MaybeObject* GeneralizeFieldRepresentation(
       int modify_index,
       Representation new_representation);
 
   // Add a property to a fast-case object.
   MUST_USE_RESULT MaybeObject* AddFastProperty(
       Name* name,
       Object* value,
       PropertyAttributes attributes,
-      StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED);
+      StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED,
+      ValueType value_type = REAL_VALUE);
 
   // Add a property to a slow-case object.
   MUST_USE_RESULT MaybeObject* AddSlowProperty(Name* name,
                                                Object* value,
                                                PropertyAttributes attributes);
 
   // Add a property to an object. May cause GC.
   MUST_USE_RESULT MaybeObject* AddProperty(
       Name* name,
       Object* value,
       PropertyAttributes attributes,
       StrictModeFlag strict_mode,
       StoreFromKeyed store_mode = MAY_BE_STORE_FROM_KEYED,
-      ExtensibilityCheck extensibility_check = PERFORM_EXTENSIBILITY_CHECK);
+      ExtensibilityCheck extensibility_check = PERFORM_EXTENSIBILITY_CHECK,
+      ValueType value_type = REAL_VALUE);
 
   // Convert the object to use the canonical dictionary
   // representation. If the object is expected to have additional properties
   // added this number can be indicated to have the backing store allocated to
   // an initial capacity for holding these properties.
   static void NormalizeProperties(Handle<JSObject> object,
                                   PropertyNormalizationMode mode,
                                   int expected_additional_properties);
 
   MUST_USE_RESULT MaybeObject* NormalizeProperties(
@@ skipping 7396 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_