Improve load IC so it can call a native accessor even if the holder is

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 77 matching lines @@
   }
   return false;
 }
 
 
 bool TypeFeedbackOracle::LoadIsMonomorphicNormal(Property* expr) {
   Handle<Object> map_or_code = GetInfo(expr->id());
   if (map_or_code->IsMap()) return true;
   if (map_or_code->IsCode()) {
     Handle<Code> code = Handle<Code>::cast(map_or_code);
-    return code->is_keyed_load_stub() &&
+    bool preliminary_checks = code->is_keyed_load_stub() &&
         code->ic_state() == MONOMORPHIC &&
-        Code::ExtractTypeFromFlags(code->flags()) == Code::NORMAL &&
-        code->FindFirstMap() != NULL &&
-        !CanRetainOtherContext(code->FindFirstMap(), *global_context_);
+        Code::ExtractTypeFromFlags(code->flags()) == Code::NORMAL;
+    if (!preliminary_checks) return false;
+    Map* map = code->FindFirstMap();
+    return map != NULL && !CanRetainOtherContext(map, *global_context_);
   }
   return false;
 }
 
 
 bool TypeFeedbackOracle::LoadIsMegamorphicWithTypeInfo(Property* expr) {
   Handle<Object> map_or_code = GetInfo(expr->id());
   if (map_or_code->IsCode()) {
     Handle<Code> code = Handle<Code>::cast(map_or_code);
     Builtins* builtins = isolate_->builtins();
     return code->is_keyed_load_stub() &&
         *code != builtins->builtin(Builtins::kKeyedLoadIC_Generic) &&
         code->ic_state() == MEGAMORPHIC;
   }
   return false;
 }
 
 
 bool TypeFeedbackOracle::StoreIsMonomorphicNormal(Expression* expr) {
   Handle<Object> map_or_code = GetInfo(expr->id());
   if (map_or_code->IsMap()) return true;
   if (map_or_code->IsCode()) {
     Handle<Code> code = Handle<Code>::cast(map_or_code);
     bool allow_growth =
         Code::GetKeyedAccessGrowMode(code->extra_ic_state()) ==
         ALLOW_JSARRAY_GROWTH;
-    return code->is_keyed_store_stub() &&
+    bool preliminary_checks =
+        code->is_keyed_store_stub() &&
         !allow_growth &&
         code->ic_state() == MONOMORPHIC &&
-        Code::ExtractTypeFromFlags(code->flags()) == Code::NORMAL &&
-        code->FindFirstMap() != NULL &&
-        !CanRetainOtherContext(code->FindFirstMap(), *global_context_);
+        Code::ExtractTypeFromFlags(code->flags()) == Code::NORMAL;
+    if (!preliminary_checks) return false;
+    Map* map = code->FindFirstMap();
+    return map != NULL && !CanRetainOtherContext(map, *global_context_);
   }
   return false;
 }
 
 
 bool TypeFeedbackOracle::StoreIsMegamorphicWithTypeInfo(Expression* expr) {
   Handle<Object> map_or_code = GetInfo(expr->id());
   if (map_or_code->IsCode()) {
     Handle<Code> code = Handle<Code>::cast(map_or_code);
     Builtins* builtins = isolate_->builtins();
@@ skipping 572 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