(num_procs - rank - 1) * recv_count, send_type,
rank, tag, tmp_buff, (num_procs - rank - 1) * recv_count,
recv_type, rank, tag, comm, &status);
(num_procs - rank - 1) * recv_count, send_type,
rank, tag, tmp_buff, (num_procs - rank - 1) * recv_count,
recv_type, rank, tag, comm, &status);