Remove unnecessary elements type check when allocating array in runtime.

src/builtins.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 200 matching lines @@
     if (!maybe_obj->To(&array)) return maybe_obj;
   }
 
   // Optimize the case where there is one argument and the argument is a
   // small smi.
   if (args->length() == 2) {
     Object* obj = (*args)[1];
     if (obj->IsSmi()) {
       int len = Smi::cast(obj)->value();
       if (len >= 0 && len < JSObject::kInitialMaxFastElementArray) {
-        Object* obj;
+        Object* fixed_array;
         { MaybeObject* maybe_obj = heap->AllocateFixedArrayWithHoles(len);
-          if (!maybe_obj->ToObject(&obj)) return maybe_obj;
+          if (!maybe_obj->ToObject(&fixed_array)) return maybe_obj;
         }
-        MaybeObject* maybe_obj = array->SetContent(FixedArray::cast(obj));
-        if (maybe_obj->IsFailure()) return maybe_obj;
+        array->set_elements(FixedArray::cast(fixed_array));

[danno, 2012/02/15 12:08:11]

Add a comment why SetContent isn't a good idea here.

+        array->set_length(Smi::cast(obj));
         return array;
       }
     }
     // Take the argument as the length.
     { MaybeObject* maybe_obj = array->Initialize(0);
       if (!maybe_obj->ToObject(&obj)) return maybe_obj;
     }
     return array->SetElementsLength((*args)[1]);
   }
 
@@ skipping 1519 matching lines @@
   return Handle<Code>(code_address);                        \
 }
 BUILTIN_LIST_C(DEFINE_BUILTIN_ACCESSOR_C)
 BUILTIN_LIST_A(DEFINE_BUILTIN_ACCESSOR_A)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 
 
 } }  // namespace v8::internal