crankshaft support for api method calls

src/stub-cache.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 1920 matching lines @@
   }
 }
 
 
 CallOptimization::CallOptimization(Handle<JSFunction> function) {
   Initialize(function);
 }
 
 
 Handle<Map> CallOptimization::LookupHolderOfExpectedType(
-    Handle<JSObject> receiver,
-    Handle<JSObject> object,
-    Handle<JSObject> holder,
+    Handle<Map> receiver_map,
+    Handle<Map> object_map,
+    Handle<Map> holder_map,
     HolderLookup* holder_lookup) const {
   ASSERT(is_simple_api_call());
   ASSERT_EQ(kHolderNotFound, *holder_lookup);
   *holder_lookup = kHolderIsReceiver;
   Handle<Map> map_to_holder;
   if (expected_receiver_type_.is_null()) {
     // no expected type, load from receiver.
     return map_to_holder;
   }
   // walk down the prototype chain to the object
-  while (!receiver.is_identical_to(object)) {
+  while (!receiver_map.is_identical_to(object_map)) {
     *holder_lookup = kHolderIsPrototypeOfMap;
-    map_to_holder = Handle<Map>(receiver->map());
-    receiver = Handle<JSObject>(JSObject::cast(map_to_holder->prototype()));
+    map_to_holder = receiver_map;
+    receiver_map =
+        Handle<Map>(JSObject::cast(map_to_holder->prototype())->map());
   }
   // start looking for the holder
-  while (!object.is_identical_to(holder)) {
-    Handle<Map> object_map(object->map());
+  while (!object_map.is_identical_to(holder_map)) {

[Toon Verwaest, 2014/01/29 13:22:39]

Please extract this implicit magic to an explicit
"CanElideApiHolderPrototypeChainCheck" with a comment indicating that we can
remove it if the API holder is between the receiver and the holder, which is
checked by the regular prototype chain check.

     if (expected_receiver_type_->IsTemplateFor(*object_map)) {
       return map_to_holder;
     }
+    *holder_lookup = kHolderIsPrototypeOfMap;
+    map_to_holder = object_map;
+    object_map = Handle<Map>(JSObject::cast(object_map->prototype())->map());
     if (!object_map->is_hidden_prototype()) {
       *holder_lookup = kHolderNotFound;
       return Handle<Map>::null();
     }
-    *holder_lookup = kHolderIsPrototypeOfMap;
-    map_to_holder = object_map;
-    object = Handle<JSObject>(JSObject::cast(object_map->prototype()));
   }
-  if (expected_receiver_type_->IsTemplateFor(holder->map())) {
+  if (expected_receiver_type_->IsTemplateFor(*object_map)) {
     return map_to_holder;
   }
   *holder_lookup = kHolderNotFound;
   return Handle<Map>::null();
 }
 
 
 void CallOptimization::Initialize(Handle<JSFunction> function) {
   constant_function_ = Handle<JSFunction>::null();
   is_simple_api_call_ = false;
@@ skipping 27 matching lines @@
           Handle<FunctionTemplateInfo>(
               FunctionTemplateInfo::cast(signature->receiver()));
     }
   }
 
   is_simple_api_call_ = true;
 }
 
 
 } }  // namespace v8::internal