http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52588
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-03-15 08:58:14 UTC --- I don't think there is a way for the compiler to see if idx_5 is within the range of [0, 9]. So we are warning for the cases where idx_5 is out of the range really.