Using Coarrays to Parallelize Legacy Fortran Applications: Strategy and Case Study

Listing 4

Parallel loop by splitting bands.

! Loop over the bands

do k = my_first_band, my_last_band

  ! Global number

  ! of last particle in (k − 1) band

  l = k ** 2 + (k − 1) ** 2 − 1

  ! Loop over the particles in band

   do m = 1, k

    ! First octant

    l = l + 1

    ! Do some computations

    ! Second octant

    l = l + 1

    ! Do some computations

    ! Third octant

    l = l + 1

    ! Do some computations

    ! Fourth octant

    l = l + 1

    ! Do some computations

   end do

end do