Request::sendrecv(sendptr, send_count, send_type, dst, tag,
recvptr + recv_disps[src] * extent, recv_counts[src], recv_type,
src, tag, comm, &status);
Request::sendrecv(sendptr, send_count, send_type, dst, tag,
recvptr + recv_disps[src] * extent, recv_counts[src], recv_type,
src, tag, comm, &status);