https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53852
--- Comment #19 from Sebastian Pop <spop at gcc dot gnu.org> --- Patch fixing the compile time problem with at least isl-0.15: https://gcc.gnu.org/ml/gcc-patches/2015-09/msg00198.html isl-0.12 does not support the compute-out mechanism.