[Bug middle-end/49543] Cast move causes incorrect code and numerical results

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49543

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-06-27 
17:40:01 UTC ---
    /* Data - 1 overflows */

Yes that would mean it is undefined code.  Try -fwrapv.