[Bug fortran/109701] I have a MWE where an omp reduction breaks if I add the option for GPU offloading (even if it isn't used).

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109701

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |INVALID
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This is a user error.
The OpenMP standard makes reduction vars mapped on target only on combined
constructs with the target construct, which is not the case here.
If you'd use
!$omp target teams distribute parallel do simd if(target:is_GPU)
reduction(max:max_diff) collapse(2)
then max_diff would be mapped.  But as it is on a different constructs, the
standard rules apply there and max_diff is firstprivatized instead (as it is
scalar, no defaultmap clause is used etc.).  So, if that isn't what you want,
you need to map
it explicitly map(tofrom:max_diff) or so on the target.