nb_sum_reduce_complex_4array_sub Subroutine

  subroutine nb_sum_reduce_complex_4array_sub (z, dest, sub, request)
    implicit none
    complex, dimension (:,:,:,:), intent (in out) :: z
    integer, intent (in) :: dest
    type(comm_type), intent(in) :: sub
    integer, intent (out) :: request
# ifdef MPI3
    integer :: ierror
!$OMP MASTER
    call time_message(.false., time_mp_collectives, ' MPI Collectives')
!$OMP END MASTER
    if(sub%iproc.eq.dest) then
       call mpi_ireduce &
            (MPI_IN_PLACE, z, size(z), mpicmplx, MPI_SUM, dest, sub%id, request, ierror)
    else
       call mpi_ireduce &
            (z, z, size(z), mpicmplx, MPI_SUM, dest, sub%id, request, ierror)
    endif
!$OMP MASTER
    call time_message(.false., time_mp_collectives, ' MPI Collectives')
!$OMP END MASTER
# else
    call sum_reduce_complex_4array_sub(z, dest, sub)
    request = mp_request_null
# endif
  end subroutine nb_sum_reduce_complex_4array_sub