Polymorphism support for load IC.

src/type-info.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 320 matching lines @@
   return *GetInfo(expr->PropertyFeedbackId()) ==
       isolate_->builtins()->builtin(id);
 }
 
 
 bool TypeFeedbackOracle::LoadIsStub(Property* expr, ICStub* stub) {
   Handle<Object> object = GetInfo(expr->PropertyFeedbackId());
   if (!object->IsCode()) return false;
   Handle<Code> code = Handle<Code>::cast(object);
   if (!code->is_load_stub()) return false;
+  if (code->ic_state() != MONOMORPHIC) return false;
   return stub->Describes(*code);
 }
 
 
 static TypeInfo TypeFromCompareType(CompareIC::State state) {
   switch (state) {
     case CompareIC::UNINITIALIZED:
       // Uninitialized means never executed.
       return TypeInfo::Uninitialized();
     case CompareIC::SMI:
@@ skipping 156 matching lines @@
     case BinaryOpIC::GENERIC:
       return unknown;
     default:
       return unknown;
   }
   UNREACHABLE();
   return unknown;
 }
 
 
+static void AddMapIfMissing(Handle<Map> map, SmallMapList* list,
+                            Zone* zone) {
+  for (int i = 0; i < list->length(); ++i) {
+    if (list->at(i).is_identical_to(map)) return;
+  }
+  list->Add(map, zone);
+}
+
+
+void TypeFeedbackOracle::CollectPolymorphicMaps(Handle<Code> code,
+                                                SmallMapList* types) {
+  MapHandleList maps;
+  code->FindAllMaps(&maps);
+  types->Reserve(maps.length(), zone());
+  for (int i = 0; i < maps.length(); i++) {
+    Handle<Map> map(maps.at(i));
+    if (!CanRetainOtherContext(*map, *native_context_)) {
+      AddMapIfMissing(map, types, zone());
+    }
+  }
+}
+
+
 void TypeFeedbackOracle::CollectReceiverTypes(TypeFeedbackId ast_id,
                                               Handle<String> name,
                                               Code::Flags flags,
                                               SmallMapList* types) {
   Handle<Object> object = GetInfo(ast_id);
   if (object->IsUndefined() || object->IsSmi()) return;
 
   if (object.is_identical_to(isolate_->builtins()->StoreIC_GlobalProxy())) {
     // TODO(fschneider): We could collect the maps and signal that
     // we need a generic store (or load) here.
     ASSERT(Handle<Code>::cast(object)->ic_state() == GENERIC);
   } else if (object->IsMap()) {
     types->Add(Handle<Map>::cast(object), zone());
+  } else if (Handle<Code>::cast(object)->ic_state() == POLYMORPHIC) {
+    CollectPolymorphicMaps(Handle<Code>::cast(object), types);
   } else if (FLAG_collect_megamorphic_maps_from_stub_cache &&
       Handle<Code>::cast(object)->ic_state() == MEGAMORPHIC) {
     types->Reserve(4, zone());
     ASSERT(object->IsCode());
     isolate_->stub_cache()->CollectMatchingMaps(types,
                                                 *name,
                                                 flags,
                                                 native_context_,
                                                 zone());
   }
@@ skipping 27 matching lines @@
 }
 
 
 bool TypeFeedbackOracle::CanRetainOtherContext(JSFunction* function,
                                                Context* native_context) {
   return function->context()->global_object() != native_context->global_object()
       && function->context()->global_object() != native_context->builtins();
 }
 
 
-static void AddMapIfMissing(Handle<Map> map, SmallMapList* list,
-                            Zone* zone) {
-  for (int i = 0; i < list->length(); ++i) {
-    if (list->at(i).is_identical_to(map)) return;
-  }
-  list->Add(map, zone);
-}
-
-
 void TypeFeedbackOracle::CollectKeyedReceiverTypes(TypeFeedbackId ast_id,
                                                    SmallMapList* types) {
   Handle<Object> object = GetInfo(ast_id);
   if (!object->IsCode()) return;
   Handle<Code> code = Handle<Code>::cast(object);
   if (code->kind() == Code::KEYED_LOAD_IC ||
       code->kind() == Code::KEYED_STORE_IC) {
-    AssertNoAllocation no_allocation;
-    int mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
-    for (RelocIterator it(*code, mask); !it.done(); it.next()) {
-      RelocInfo* info = it.rinfo();
-      Object* object = info->target_object();
-      if (object->IsMap()) {
-        Map* map = Map::cast(object);
-        if (!CanRetainOtherContext(map, *native_context_)) {
-          AddMapIfMissing(Handle<Map>(map), types, zone());
-        }
-      }
-    }
+    CollectPolymorphicMaps(code, types);
   }
 }
 
 
 byte TypeFeedbackOracle::ToBooleanTypes(TypeFeedbackId ast_id) {
   Handle<Object> object = GetInfo(ast_id);
   return object->IsCode() ? Handle<Code>::cast(object)->to_boolean_state() : 0;
 }
 
 
@@ skipping 125 matching lines @@
   USE(maybe_result);
 #ifdef DEBUG
   Object* result = NULL;
   // Dictionary has been allocated with sufficient size for all elements.
   ASSERT(maybe_result->ToObject(&result));
   ASSERT(*dictionary_ == result);
 #endif
 }
 
 } }  // namespace v8::internal