Track field types.

src/ic.cc

 // 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 1153 matching lines @@
   PropertyDetails target_details = lookup->GetTransitionDetails();
   if (target_details.IsReadOnly()) return false;
 
   // If the value that's being stored does not fit in the field that the
   // instance would transition to, create a new transition that fits the value.
   // This has to be done before generating the IC, since that IC will embed the
   // transition target.
   // Ensure the instance and its map were migrated before trying to update the
   // transition target.
   ASSERT(!receiver->map()->is_deprecated());
+  Handle<HeapType> value_type = FLAG_track_field_types
+      ? HeapType::OfCurrently(value, lookup->isolate())
+      : HeapType::Any(lookup->isolate());
+  Handle<Map> target(lookup->GetTransitionTarget());
   if (!value->FitsRepresentation(target_details.representation())) {
-    Handle<Map> target(lookup->GetTransitionTarget());
     Map::GeneralizeRepresentation(
         target, target->LastAdded(),
-        value->OptimalRepresentation(), FORCE_FIELD);
+        value->OptimalRepresentation(),
+        value_type, FORCE_FIELD);
     // Lookup the transition again since the transition tree may have changed
     // entirely by the migration above.
     receiver->map()->LookupTransition(*holder, *name, lookup);
     if (!lookup->IsTransition()) return false;
     ic->MarkMonomorphicPrototypeFailure();
+  } else if (target_details.type() == FIELD &&
+             target_details.representation().IsHeapObject()) {
+    int descriptor_number = target->LastAdded();
+    Handle<DescriptorArray> target_descriptors(target->instance_descriptors());
+    Handle<HeapType> field_type(target_descriptors->GetFieldType(
+            descriptor_number), lookup->isolate());
+    if (!value_type->IsCurrently(field_type)) {
+      if (!field_type->IsCurrently(value_type)) {
+        value_type = HeapType::Any(lookup->isolate());
+      }
+      if (FLAG_trace_track_field_types) {
+#ifdef OBJECT_PRINT
+        PrintF("[Updating type of field ");
+        name->Print();
+        PrintF(" in transition map ");
+        target->ShortPrint();
+        PrintF(": ");
+        field_type->TypePrint(stdout);
+        PrintF(" -> ");
+        value_type->TypePrint(stdout);
+        PrintF("]\n");
+#endif
+      }
+      target->UpdateFieldType(descriptor_number, *value_type);
+      ic->MarkMonomorphicPrototypeFailure();
+    }
   }
   return true;
 }
 
 
 MaybeObject* StoreIC::Store(Handle<Object> object,
                             Handle<String> name,
                             Handle<Object> value,
                             JSReceiver::StoreFromKeyed store_mode) {
   if (MigrateDeprecated(object) || object->IsJSProxy()) {
@@ skipping 1639 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal