1) binomial_tree reduce inside each SMP node
2) binomial_tree reduce intra-communication between root of each SMP node
3) binomial_tree bcast intra-communication between root of each SMP node
4) binomial_tree bcast inside each SMP node
*/
1) binomial_tree reduce inside each SMP node
2) binomial_tree reduce intra-communication between root of each SMP node
3) binomial_tree bcast intra-communication between root of each SMP node
4) binomial_tree bcast inside each SMP node
*/