[flang][openmp] Please address not yet implemented: Unhandled clause reduction in omp.simd operation

[sscalpone]

A widely-used close-source app uses OpenMP SIMD reductions. It would be great if this feature was implemented. Thanks!

module foo
  implicit none

contains
  subroutine bar(arr,n_elem)
    integer i
    integer n_elem
    double precision arr(:),resul

    resul=0d0
 !$OMP SIMD REDUCTION(+:resul)
    do i=1,n_elem
       resul=resul+arr(i)*i
    enddo

  end subroutine bar
end module foo

% flang -fopenmp -c foo.f90
flang-21: warning: OpenMP support in flang is still experimental [-Wexperimental-option]
error: loc(".../foo.f90":11:8): not yet implemented: Unhandled clause reduction in omp.simd operation
error: loc(".../foo.f90":11:8): LLVM Translation failed for operation: omp.simd
error: failed to create the LLVM module