https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70729
--- Comment #31 from Jakub Jelinek <jakub at gcc dot gnu.org> --- A question is if #pragma GCC ivdep has similar guarantees/restrictions; the documentation only disallows certain loop-carried dependencies, in particular those that would prevent vectorization, so I think it is the same as unspecified (== infinite) safelen on #pragma omp simd.