Revert change to always call builtins for Array functions....

src/builtins.cc

 // Copyright 2006-2008 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 301 matching lines @@
   ASSERT(proto->elements() == Heap::empty_fixed_array());
   // Object.prototype
   proto = JSObject::cast(proto->GetPrototype());
   if (proto != global_context->initial_object_prototype()) return false;
   if (proto->elements() != Heap::empty_fixed_array()) return false;
   ASSERT(proto->GetPrototype()->IsNull());
   return true;
 }
 
 
-static bool IsJSArrayWithFastElements(Object* receiver,
-                                      FixedArray** elements) {
-  if (!receiver->IsJSArray()) {
-    return false;
-  }
-
-  JSArray* array = JSArray::cast(receiver);
-
-  HeapObject* elms = HeapObject::cast(array->elements());
-  if (elms->map() != Heap::fixed_array_map()) {
-    return false;
-  }
-
-  *elements = FixedArray::cast(elms);
-  return true;
-}
-
-
 static Object* CallJsBuiltin(const char* name,
                              BuiltinArguments<NO_EXTRA_ARGUMENTS> args) {
   HandleScope handleScope;
 
   Handle<Object> js_builtin =
       GetProperty(Handle<JSObject>(Top::global_context()->builtins()),
                   name);
   ASSERT(js_builtin->IsJSFunction());
   Handle<JSFunction> function(Handle<JSFunction>::cast(js_builtin));
   Vector<Object**> argv(Vector<Object**>::New(args.length() - 1));
   int n_args = args.length() - 1;
   for (int i = 0; i < n_args; i++) {
     argv[i] = &args[i + 1];
   }
   bool pending_exception = false;
   Handle<Object> result = Execution::Call(function,
                                           args.receiver(),
                                           n_args,
                                           argv.start(),
                                           &pending_exception);
   argv.Dispose();
   if (pending_exception) return Failure::Exception();
   return *result;
 }
 
 
 BUILTIN(ArrayPush) {
-  Object* receiver = *args.receiver();
-  FixedArray* elms = NULL;
-  if (!IsJSArrayWithFastElements(receiver, &elms)) {
-    return CallJsBuiltin("ArrayPush", args);
-  }
-  JSArray* array = JSArray::cast(receiver);
+  JSArray* array = JSArray::cast(*args.receiver());
+  ASSERT(array->HasFastElements());
 
   int len = Smi::cast(array->length())->value();
   int to_add = args.length() - 1;
   if (to_add == 0) {
     return Smi::FromInt(len);
   }
   // Currently fixed arrays cannot grow too big, so
   // we should never hit this case.
   ASSERT(to_add <= (Smi::kMaxValue - len));
 
   int new_length = len + to_add;
+  FixedArray* elms = FixedArray::cast(array->elements());
 
   if (new_length > elms->length()) {
     // New backing storage is needed.
     int capacity = new_length + (new_length >> 1) + 16;
     Object* obj = Heap::AllocateUninitializedFixedArray(capacity);
     if (obj->IsFailure()) return obj;
     FixedArray* new_elms = FixedArray::cast(obj);
 
     AssertNoAllocation no_gc;
     CopyElements(&no_gc, new_elms, 0, elms, 0, len);
@@ skipping 10 matching lines @@
     elms->set(index + len, args[index + 1], mode);
   }
 
   // Set the length.
   array->set_length(Smi::FromInt(new_length));
   return Smi::FromInt(new_length);
 }
 
 
 BUILTIN(ArrayPop) {
-  Object* receiver = *args.receiver();
-  FixedArray* elms = NULL;
-  if (!IsJSArrayWithFastElements(receiver, &elms)) {
-    return CallJsBuiltin("ArrayPop", args);
-  }
-  JSArray* array = JSArray::cast(receiver);
+  JSArray* array = JSArray::cast(*args.receiver());
+  ASSERT(array->HasFastElements());
 
   int len = Smi::cast(array->length())->value();
   if (len == 0) return Heap::undefined_value();
 
   // Get top element
+  FixedArray* elms = FixedArray::cast(array->elements());
   Object* top = elms->get(len - 1);
 
   // Set the length.
   array->set_length(Smi::FromInt(len - 1));
 
   if (!top->IsTheHole()) {
     // Delete the top element.
     elms->set_the_hole(len - 1);
     return top;
   }
 
   // Remember to check the prototype chain.
   JSFunction* array_function =
       Top::context()->global_context()->array_function();
   JSObject* prototype = JSObject::cast(array_function->prototype());
   top = prototype->GetElement(len - 1);
 
   return top;
 }
 
 
 BUILTIN(ArrayShift) {
-  Object* receiver = *args.receiver();
-  FixedArray* elms = NULL;
-  if (!IsJSArrayWithFastElements(receiver, &elms)
-      || !ArrayPrototypeHasNoElements()) {
+  if (!ArrayPrototypeHasNoElements()) {
     return CallJsBuiltin("ArrayShift", args);
   }
-  JSArray* array = JSArray::cast(receiver);
+
+  JSArray* array = JSArray::cast(*args.receiver());
   ASSERT(array->HasFastElements());
 
   int len = Smi::cast(array->length())->value();
   if (len == 0) return Heap::undefined_value();
 
+  FixedArray* elms = FixedArray::cast(array->elements());
+
   // Get first element
   Object* first = elms->get(0);
   if (first->IsTheHole()) {
     first = Heap::undefined_value();
   }
 
   // Shift the elements.
   AssertNoAllocation no_gc;
   MoveElements(&no_gc, elms, 0, elms, 1, len - 1);
   elms->set(len - 1, Heap::the_hole_value());
 
   // Set the length.
   array->set_length(Smi::FromInt(len - 1));
 
   return first;
 }
 
 
 BUILTIN(ArrayUnshift) {
-  Object* receiver = *args.receiver();
-  FixedArray* elms = NULL;
-  if (!IsJSArrayWithFastElements(receiver, &elms)
-      || !ArrayPrototypeHasNoElements()) {
+  if (!ArrayPrototypeHasNoElements()) {
     return CallJsBuiltin("ArrayUnshift", args);
   }
-  JSArray* array = JSArray::cast(receiver);
+
+  JSArray* array = JSArray::cast(*args.receiver());
   ASSERT(array->HasFastElements());
 
   int len = Smi::cast(array->length())->value();
   int to_add = args.length() - 1;
   // Note that we cannot quit early if to_add == 0 as
   // values should be lifted from prototype into
   // the array.
 
   int new_length = len + to_add;
   // Currently fixed arrays cannot grow too big, so
   // we should never hit this case.
   ASSERT(to_add <= (Smi::kMaxValue - len));
 
+  FixedArray* elms = FixedArray::cast(array->elements());
+
   if (new_length > elms->length()) {
     // New backing storage is needed.
     int capacity = new_length + (new_length >> 1) + 16;
     Object* obj = Heap::AllocateUninitializedFixedArray(capacity);
     if (obj->IsFailure()) return obj;
     FixedArray* new_elms = FixedArray::cast(obj);
 
     AssertNoAllocation no_gc;
     CopyElements(&no_gc, new_elms, to_add, elms, 0, len);
     FillWithHoles(new_elms, new_length, capacity);
@@ skipping 12 matching lines @@
     elms->set(i, args[i + 1], mode);
   }
 
   // Set the length.
   array->set_length(Smi::FromInt(new_length));
   return Smi::FromInt(new_length);
 }
 
 
 BUILTIN(ArraySlice) {
-  Object* receiver = *args.receiver();
-  FixedArray* elms = NULL;
-  if (!IsJSArrayWithFastElements(receiver, &elms)
-      || !ArrayPrototypeHasNoElements()) {
+  if (!ArrayPrototypeHasNoElements()) {
     return CallJsBuiltin("ArraySlice", args);
   }
-  JSArray* array = JSArray::cast(receiver);
+
+  JSArray* array = JSArray::cast(*args.receiver());
   ASSERT(array->HasFastElements());
 
   int len = Smi::cast(array->length())->value();
 
   int n_arguments = args.length() - 1;
 
   // Note carefully choosen defaults---if argument is missing,
   // it's undefined which gets converted to 0 for relative_start
   // and to len for relative_end.
   int relative_start = 0;
@@ skipping 30 matching lines @@
   }
 
   Object* result = AllocateJSArray();
   if (result->IsFailure()) return result;
   JSArray* result_array = JSArray::cast(result);
 
   result = Heap::AllocateUninitializedFixedArray(result_len);
   if (result->IsFailure()) return result;
   FixedArray* result_elms = FixedArray::cast(result);
 
+  FixedArray* elms = FixedArray::cast(array->elements());
+
   AssertNoAllocation no_gc;
   CopyElements(&no_gc, result_elms, 0, elms, k, result_len);
 
   // Set elements.
   result_array->set_elements(result_elms);
 
   // Set the length.
   result_array->set_length(Smi::FromInt(result_len));
   return result_array;
 }
 
 
 BUILTIN(ArraySplice) {
-  Object* receiver = *args.receiver();
-  FixedArray* elms = NULL;
-  if (!IsJSArrayWithFastElements(receiver, &elms)
-      || !ArrayPrototypeHasNoElements()) {
+  if (!ArrayPrototypeHasNoElements()) {
     return CallJsBuiltin("ArraySplice", args);
   }
-  JSArray* array = JSArray::cast(receiver);
+
+  JSArray* array = JSArray::cast(*args.receiver());
   ASSERT(array->HasFastElements());
 
   int len = Smi::cast(array->length())->value();
 
   int n_arguments = args.length() - 1;
 
   // SpiderMonkey and JSC return undefined in the case where no
   // arguments are given instead of using the implicit undefined
   // arguments.  This does not follow ECMA-262, but we do the same for
   // compatibility.
@@ skipping 20 matching lines @@
   if (n_arguments > 1) {
     Object* arg2 = args[2];
     if (arg2->IsSmi()) {
       delete_count = Smi::cast(arg2)->value();
     } else {
       return CallJsBuiltin("ArraySplice", args);
     }
   }
   int actual_delete_count = Min(Max(delete_count, 0), len - actual_start);
 
+  FixedArray* elms = FixedArray::cast(array->elements());
+
   JSArray* result_array = NULL;
   if (actual_delete_count == 0) {
     Object* result = AllocateEmptyJSArray();
     if (result->IsFailure()) return result;
     result_array = JSArray::cast(result);
   } else {
     // Allocate result array.
     Object* result = AllocateJSArray();
     if (result->IsFailure()) return result;
     result_array = JSArray::cast(result);
@@ skipping 718 matching lines @@
       if (entry->contains(pc)) {
         return names_[i];
       }
     }
   }
   return NULL;
 }
 
 
 } }  // namespace v8::internal