sum_reduce_complex_2array_sub Subroutine

  subroutine sum_reduce_complex_2array_sub (z, dest, sub)
    implicit none
    complex, dimension (:,:), intent (in out) :: z
    integer, intent (in) :: dest
    type(comm_type), intent(in) :: sub
# ifdef MPI
    integer :: ierror
!$OMP MASTER
    call time_message(.false., time_mp_collectives, ' MPI Collectives')
!$OMP END MASTER
    if(sub%iproc.eq.dest) then
       call mpi_reduce &
            (MPI_IN_PLACE, z, size(z), mpicmplx, MPI_SUM, dest, sub%id, ierror)
    else
       call mpi_reduce &
            (z, z, size(z), mpicmplx, MPI_SUM, dest, sub%id, ierror)
    endif
!$OMP MASTER
    call time_message(.false., time_mp_collectives, ' MPI Collectives')
!$OMP END MASTER
# else
    UNUSED_DUMMY(z); UNUSED_DUMMY(sub)
    if (dest /= 0) call mp_abort ("reduce to")
# endif
  end subroutine sum_reduce_complex_2array_sub