1 /* Copyright (c) 2013-2014. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
7 #include "../colls_private.h"
9 /*****************************************************************************
11 * Function: alltoall_pair
16 send_buff: send input buffer
17 send_count: number of elements to send
18 send_type: data type of elements being sent
19 recv_buff: receive output buffer
20 recv_count: number of elements to received
21 recv_type: data type of elements being received
24 * Descrp: Function works when P is power of two. In each phase of P - 1
25 phases, nodes in pair communicate their data.
29 ****************************************************************************/
32 int Coll_alltoall_pair_rma::alltoall(void *send_buff, int send_count, MPI_Datatype send_type,
33 void *recv_buff, int recv_count, MPI_Datatype recv_type,
37 MPI_Aint send_chunk, recv_chunk;
40 int i, dst, rank, num_procs;
42 char *send_ptr = (char *) send_buff;
45 num_procs = comm->size();
46 send_chunk = send_type->get_extent();
47 recv_chunk = recv_type->get_extent();
49 win=new Win(recv_buff, num_procs * recv_chunk * send_count, recv_chunk, 0,
51 send_chunk *= send_count;
52 recv_chunk *= recv_count;
55 for (i = 0; i < num_procs; i++) {
57 win->put(send_ptr + dst * send_chunk, send_count, send_type, dst,
58 rank /* send_chunk*/, send_count, send_type);
66 int Coll_alltoall_pair::alltoall(void *send_buff, int send_count,
67 MPI_Datatype send_type,
68 void *recv_buff, int recv_count,
69 MPI_Datatype recv_type, MPI_Comm comm)
72 MPI_Aint send_chunk, recv_chunk;
74 int i, src, dst, rank, num_procs;
75 int tag = COLL_TAG_ALLTOALL;
76 char *send_ptr = (char *) send_buff;
77 char *recv_ptr = (char *) recv_buff;
80 num_procs = comm->size();
82 if((num_procs&(num_procs-1)))
83 THROWF(arg_error,0, "alltoall pair algorithm can't be used with non power of two number of processes ! ");
85 send_chunk = send_type->get_extent();
86 recv_chunk = recv_type->get_extent();
88 send_chunk *= send_count;
89 recv_chunk *= recv_count;
91 for (i = 0; i < num_procs; i++) {
93 Request::sendrecv(send_ptr + dst * send_chunk, send_count, send_type, dst, tag,
94 recv_ptr + src * recv_chunk, recv_count, recv_type, src, tag,