MPI_Ibsend (&buf[send_t_number * 2 * BUF_SIZE], BUF_SIZE, MPI_INT,
1, send_t_number * 2, comm, &aReq[send_t_number * 2]);
MPI_Ibsend (&buf[(send_t_number * 2 + 1) * BUF_SIZE],
MPI_Ibsend (&buf[send_t_number * 2 * BUF_SIZE], BUF_SIZE, MPI_INT,
1, send_t_number * 2, comm, &aReq[send_t_number * 2]);
MPI_Ibsend (&buf[(send_t_number * 2 + 1) * BUF_SIZE],