Track field types.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index a87e389883e5e59035095219e19f726810ea21cb..1e6c5324282c15baa357726f9988b854ff200168 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1495,7 +1495,8 @@ class Object : public MaybeObject {
       return Representation::Smi();
     } else if (FLAG_track_double_fields && IsHeapNumber()) {
       return Representation::Double();
-    } else if (FLAG_track_computed_fields && IsUninitialized()) {
+    } else if ((FLAG_track_computed_fields ||
+                FLAG_track_heap_object_fields) && IsUninitialized()) {

[Toon Verwaest, 2014/03/21 14:33:37]

Why did you add this flag? Which piece of code passes in uninitialized for
non-computed fields?

[Benedikt Meurer, 2014/04/11 11:12:00]

This was a hack to work-around the "missing chokepoint for generalization"
issue. Fixed now.

       return Representation::None();
     } else if (FLAG_track_heap_object_fields) {
       ASSERT(IsHeapObject());
@@ -2585,6 +2586,7 @@ class JSObject: public JSReceiver {
   static void GeneralizeFieldRepresentation(Handle<JSObject> object,
                                             int modify_index,
                                             Representation new_representation,
+                                            Handle<HeapType> new_field_type,
                                             StoreMode store_mode);
 
   // Convert the object to use the canonical dictionary
@@ -3391,12 +3393,14 @@ class DescriptorArray: public FixedArray {
   inline Name* GetKey(int descriptor_number);
   inline Object** GetKeySlot(int descriptor_number);
   inline Object* GetValue(int descriptor_number);
+  inline void SetValue(int descriptor_number, Object* value);
   inline Object** GetValueSlot(int descriptor_number);
   inline Object** GetDescriptorStartSlot(int descriptor_number);
   inline Object** GetDescriptorEndSlot(int descriptor_number);
   inline PropertyDetails GetDetails(int descriptor_number);
   inline PropertyType GetType(int descriptor_number);
   inline int GetFieldIndex(int descriptor_number);
+  HeapType* GetFieldType(int descriptor_number);
   inline Object* GetConstant(int descriptor_number);
   inline Object* GetCallbacksObject(int descriptor_number);
   inline AccessorDescriptor* GetCallbacks(int descriptor_number);
@@ -3404,7 +3408,6 @@ class DescriptorArray: public FixedArray {
   inline Name* GetSortedKey(int descriptor_number);
   inline int GetSortedKeyIndex(int descriptor_number);
   inline void SetSortedKey(int pointer, int descriptor_number);
-  inline void InitializeRepresentations(Representation representation);
   inline void SetRepresentation(int descriptor_number,
                                 Representation representation);
 
@@ -5736,6 +5739,9 @@ class DependentCode: public FixedArray {
     // Group of code that depends on global property values in property cells
     // not being changed.
     kPropertyCellChangedGroup,
+    // Group of code that omit run-time type checks for the field(s) introduced
+    // by this map.
+    kFieldTypeGroup,
     // Group of code that depends on tenuring information in AllocationSites
     // not being changed.
     kAllocationSiteTenuringChangedGroup,
@@ -6011,6 +6017,10 @@ class Map: public HeapObject {
   Map* FindRootMap();
   Map* FindUpdatedMap(int verbatim, int length, DescriptorArray* descriptors);
   Map* FindLastMatchMap(int verbatim, int length, DescriptorArray* descriptors);
+  Map* FindFieldOwner(int descriptor);
+
+  void UpdateDescriptor(int descriptor_number, Descriptor* desc);
+  void UpdateFieldType(int descriptor, HeapType* field_type);
 
   inline int GetInObjectPropertyOffset(int index);
 
@@ -6020,13 +6030,12 @@ class Map: public HeapObject {
                               int target_number_of_fields,
                               int target_inobject,
                               int target_unused);
-  static Handle<Map> GeneralizeAllFieldRepresentations(
-      Handle<Map> map,
-      Representation new_representation);
+  static Handle<Map> GeneralizeAllFieldRepresentations(Handle<Map> map);
   static Handle<Map> GeneralizeRepresentation(
       Handle<Map> map,
       int modify_index,
       Representation new_representation,
+      Handle<HeapType> new_field_type,
       StoreMode store_mode);
   static Handle<Map> CopyGeneralizeAllRepresentations(
       Handle<Map> map,