https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70134
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- The reason why it is missed on the tree level is due to the code being undefined. In that it uses uninitialized variables like: if (iter_5(D) >= itmx_6(D)) goto <bb 10>; else goto <bb 7>;