https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71373
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Well, if you want something that works well with wide range of GCCs, then your
case OMP_CLAUSE_TILE:
/* OpenACC tile clauses are discarded during gimplification, so we
don't expect to see anything here. */
gcc_unreachable ();
case OMP_CLAUSE__CACHE_:
/* These clauses belong to the OpenACC cache directive, which is
discarded during gimplification, so we don't expect to see
anything here. */
gcc_unreachable ();
default:
gcc_unreachable ();
is bad, while:
/* OpenACC tile clauses are discarded during gimplification, so we
don't expect to see anything here. */
case OMP_CLAUSE_TILE:
/* These clauses belong to the OpenACC cache directive, which is
discarded during gimplification, so we don't expect to see
anything here. */
case OMP_CLAUSE__CACHE_:
default:
gcc_unreachable ();
is optimized well. The latter is optimized in GIMPLE_SWITCH during the cfg
pass. Let me file a PR for the other form (though, in this case, having a
separate gcc_unreachable () in each case is IMHO also much uglier than just
listing it next to default.
