[Bug fortran/57071] Optimize (-1)**k to 1 - 2 * mod(K, 2)

[tkoenig at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57071
--- Comment #13 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
Sorry, wrong PR for the comment.