https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70348
--- Comment #5 from Nathan Sidwell <nathan at gcc dot gnu.org> --- the intended current implementation is to treat 'sum' as firstprivate. however, putting in an explicit firstprivate causes another different ICE (in lower_oacc_reductions) -- regardless of whether 'sum' is a parameter, or a local (initialized) variable. Clearly at least two other bugs lurk.