http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46724
--- Comment #2 from Andreas Krebbel <krebbel at gcc dot gnu.org> 2010-12-02 09:51:17 UTC --- Marked as 4.6 regression. The behavior of 4.5.2 isn't helpful either but it doesn't return a wrong value as with 4.6.