1 /* Copyright (c) 2013-2022. 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.hpp"
9 /*****************************************************************************
11 Copyright (c) 2006, Ahmad Faraj & Xin Yuan,
14 Redistribution and use in source and binary forms, with or without
15 modification, are permitted provided that the following conditions are met:
17 * Redistributions of source code must retain the above copyright notice,
18 this list of conditions and the following disclaimer.
20 * Redistributions in binary form must reproduce the above copyright notice,
21 this list of conditions and the following disclaimer in the documentation
22 and/or other materials provided with the distribution.
24 * Neither the name of the Florida State University nor the names of its
25 contributors may be used to endorse or promote products derived from this
26 software without specific prior written permission.
28 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
29 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
30 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
31 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
32 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
33 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
34 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
35 ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
37 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *************************************************************************
40 * Any results obtained from executing this software require the *
41 * acknowledgment and citation of the software and its owners. *
42 * The full citation is given below: *
44 * A. Faraj and X. Yuan. "Automatic Generation and Tuning of MPI *
45 * Collective Communication Routines." The 19th ACM International *
46 * Conference on Supercomputing (ICS), Cambridge, Massachusetts, *
48 *************************************************************************
50 *****************************************************************************/
52 /*****************************************************************************
59 num: the number of processors in a communicator
63 * Descp: takes a number and tries to find a factoring of x, y mesh out of it
66 ****************************************************************************/
69 static bool is_2dmesh(int num, int* i, int* j)
72 x = sqrt(double(num));
92 /*****************************************************************************
93 * Function: allgather_2dmesh_shoot
95 * send_buff: send input buffer
96 * send_count: number of elements to send
97 * send_type: data type of elements being sent
98 * recv_buff: receive output buffer
99 * recv_count: number of elements to received
100 * recv_type: data type of elements being received
101 * comm: communication
102 * Descrp: Function realizes the allgather operation using the 2dmesh
103 * algorithm. Allgather ommunication occurs first in the x dimension then in
104 * the y dimension. The communication in each dimension follows
106 * Author: Ahmad Faraj
107 ****************************************************************************/
114 allgather__2dmesh(const void *send_buff, int send_count, MPI_Datatype
115 send_type, void *recv_buff, int recv_count,
116 MPI_Datatype recv_type, MPI_Comm comm)
120 int i, src, dst, rank, num_procs;
121 int X, Y, send_offset, recv_offset;
122 int my_row_base, my_col_base, src_row_base, block_size, num_reqs;
123 int tag = COLL_TAG_ALLGATHER;
126 num_procs = comm->size();
128 extent = send_type->get_extent();
130 block_size = extent * send_count;
132 if (not is_2dmesh(num_procs, &X, &Y))
133 throw std::invalid_argument("allgather_2dmesh algorithm can't be used with this number of processes!");
135 my_row_base = (rank / Y) * Y;
136 my_col_base = rank % Y;
142 auto* req = new MPI_Request[num_reqs];
143 MPI_Request* req_ptr = req;
145 // do local allgather/local copy
146 recv_offset = rank * block_size;
147 Datatype::copy(send_buff, send_count, send_type, (char *)recv_buff + recv_offset,
148 recv_count, recv_type);
151 for (i = 0; i < Y; i++) {
152 src = i + my_row_base;
155 recv_offset = src * block_size;
156 *(req_ptr++) = Request::irecv((char *)recv_buff + recv_offset, recv_count, recv_type, src, tag,
161 for (i = 0; i < Y; i++) {
162 dst = i + my_row_base;
165 Request::send(send_buff, send_count, send_type, dst, tag, comm);
168 Request::waitall(Y - 1, req, MPI_STATUSES_IGNORE);
173 for (i = 0; i < X; i++) {
174 src = (i * Y + my_col_base);
177 src_row_base = (src / Y) * Y;
178 recv_offset = src_row_base * block_size;
179 *(req_ptr++) = Request::irecv((char *)recv_buff + recv_offset, recv_count * Y, recv_type, src, tag,
183 for (i = 0; i < X; i++) {
184 dst = (i * Y + my_col_base);
187 send_offset = my_row_base * block_size;
188 Request::send((char *)recv_buff + send_offset, send_count * Y, send_type, dst, tag,
192 Request::waitall(X - 1, req, MPI_STATUSES_IGNORE);