https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80502
--- Comment #4 from Eric Gallager <egallager at gcc dot gnu.org> --- (In reply to Evan Nemerson from comment #3) > (In reply to Jakub Jelinek from comment #2) > > _OPENMP_SIMD is a bad idea, that namespace is reserved for OpenMP, so unless > > it shows up in the OpenMP standard, it shouldn't be added. > > Fair enough, I'll propose it to the OpenMP people: > http://forum.openmp.org/forum/viewtopic.php?f=23&t=2031 > > > Why do you need a macro? Just use #pragma omp simd etc. unconditionally, > > compilers that don't have support for such pragmas will just ignore those. > > Not necessarily; often they'll emit warnings (for GCC, -Wall even includes > -Wunknown-pragmas). I'd much rather use the preprocessor in my code than > teach people to disable warnings. > Does Michael Klemm from that discussion have an account here on this bugzilla? > I need to support alternatives in my code. For example, for SIMDe > (<https://github.com/nemequ/simde>), I try to support OpenMP SIMD and Cilk > Plus, as well as compiler-specific pragmas for GCC (GCC ivdep), ICC (simd), > and clang (clang loop ...), and I'd be happy to add more as necessary. I'd > rather not end up with something like > > #pragma omp simd > #pragma simd > #pragma GCC ivdep > #pragma clang loop vectorize(enable) > for (...) { ... } > > I'd much rather just have a few macros which will expand to the right pragma > based on preprocessor macros. Right now I'm stuck using the much less > expressive ivdep syntax for GCC unless *full* OpenMP support is enabled (or > someone defines a macro manually to indicate OpenMP SIMD support).
