1 #include "colls_private.h"
3 /*****************************************************************************
5 * Function: alltoall_pair
10 send_buff: send input buffer
11 send_count: number of elements to send
12 send_type: data type of elements being sent
13 recv_buff: receive output buffer
14 recv_count: number of elements to received
15 recv_type: data type of elements being received
18 * Descrp: Function works when P is power of two. In each phase of P - 1
19 phases, nodes in pair communicate their data.
23 ****************************************************************************/
24 int smpi_coll_tuned_alltoallv_pair(void *send_buff, int *send_counts, int *send_disps,
25 MPI_Datatype send_type,
26 void *recv_buff, int *recv_counts, int *recv_disps,
27 MPI_Datatype recv_type, MPI_Comm comm)
30 MPI_Aint send_chunk, recv_chunk;
32 int i, src, dst, rank, num_procs;
34 char *send_ptr = (char *) send_buff;
35 char *recv_ptr = (char *) recv_buff;
37 rank = smpi_comm_rank(comm);
38 num_procs = smpi_comm_size(comm);
39 send_chunk = smpi_datatype_get_extent(send_type);
40 recv_chunk = smpi_datatype_get_extent(recv_type);
42 for (i = 0; i < num_procs; i++) {
44 smpi_mpi_sendrecv(send_ptr + send_disps[dst] * send_chunk, send_counts[dst], send_type, dst, tag,
45 recv_ptr + recv_disps[src] * recv_chunk, recv_counts[src], recv_type, src, tag,