Slab geometry of one rank's owned piece of the GLOBAL boundary-ghost
frame (the four width-h bands outside the global interior, corners
included). Ownership is disjoint and exhaustive: the left/right bands
cover global rows 1..ny_g only; the bottom/top bands span the FULL
padded width 1-h..nx_g+h and therefore own the four corners. A rank
owns a band segment iff its tile touches that global edge; a
bottom/top-edge rank's segment extends into the corner columns iff it
is also a left/right-edge rank (ilo/ihi below, in LOCAL i). Ghost
cells of a rank that are NOT global-boundary cells are interior MPI-halo
words: they are refreshed from neighbour interiors by the next halo
exchange and are deliberately not part of the frame.
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| integer, | intent(in) | :: | ix1 | |||
| integer, | intent(in) | :: | iy1 | |||
| integer, | intent(in) | :: | nxl | |||
| integer, | intent(in) | :: | nyl | |||
| integer, | intent(in) | :: | nx_g | |||
| integer, | intent(in) | :: | ny_g | |||
| integer, | intent(in) | :: | h | |||
| logical, | intent(out) | :: | has_l | |||
| logical, | intent(out) | :: | has_r | |||
| logical, | intent(out) | :: | has_b | |||
| logical, | intent(out) | :: | has_t | |||
| integer, | intent(out) | :: | ilo | |||
| integer, | intent(out) | :: | ihi |