[Bug fortran/92311] Fortran and OpenMP use_device_ptr and OpenACC attach_ptr/dettach_ptr

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92311

--- Comment #6 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(In reply to Nichols A. Romero from comment #0)
> For the OpenACC program, it may be that this is part of the OpenACC spec
> that has not been implemented yet.

[That's detach/attach] This OpenACC 2.6 feature is not yet available in GCC 9
or the development version (10.0); however, it is available in the vendor
branch openacc-gcc-9 (via GCC's git repository) and there are plans to merge it
in GCC 10, cf. https://gcc.gnu.org/ml/gcc-patches/2019-10/msg00444.html
If all posted OpenACC patches get merged, expect a better/more complete OpenACC
/ OpenACC 2.6 support in GCC 10.

(In reply to Jakub Jelinek from comment #1)
> (In reply to Nichols A. Romero from comment #0)
> > You don't need a map clause here, use_device_ptr clause is enough.
> That is what OpenMP 5.0 says, but not what 4.5 said, 4.5 required at least
> one map clause, and GCC 9 implements in Fortran only OpenMP 4.0 and some
> parts of OpenMP 4.5, not OpenMP 5.0.

GCC 9 support leaving out the map clause for C/C++; GCC 10 adds support of more
of OpenMP 5 (esp. for C/C++). However, OpenMP support in GCC's Fortran compiler
is lagging behind. Given that GCC development stage 1 ends in two weeks, it is
unlikely that GCC 10 will support leaving out 'map' in Fortran programs. Sorry.