generate an overlap between the different layers. Why four versions? Because
there is right now always the trade-off between using non-blocking operations
on a layer with a trivial, linear algorithm and using the more sophisticaed
algorithms in a blocking manner.
- bcast_intra_seg used the bcast of lcomm and llcomm, similarly
to original algorithm in hierarch. However, it can segment
the message, such that we might get an overlap between the two
layers. This overlap is based on the assumption, that a process
might be done early with a bcast and can start the next one.
- bcast_intra_seg1: replaces the llcomm->bcast by isend/irecvs
to increase the overlap, keeps the lcomm->bcast however
- bcast_intra_seg2: replaced lcomm->bcast by isend/irecvs
to increase the overlap, keeps however llcomm->bcast
- bcast_intra_seg3: replaced both lcomm->bcast and llcomm->bcast
by isend/irecvs
The code is lightly tested, more testing to follow right now.
This commit was SVN r19358.