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 ****************************************************************************/
109 namespace simgrid::smpi {
112 allgather__2dmesh(const void *send_buff, int send_count, MPI_Datatype
113 send_type, void *recv_buff, int recv_count,
114 MPI_Datatype recv_type, MPI_Comm comm)
118 int i, src, dst, rank, num_procs;
119 int X, Y, send_offset, recv_offset;
120 int my_row_base, my_col_base, src_row_base, block_size, num_reqs;
121 int tag = COLL_TAG_ALLGATHER;
124 num_procs = comm->size();
126 extent = send_type->get_extent();
128 block_size = extent * send_count;
130 if (not is_2dmesh(num_procs, &X, &Y))
131 throw std::invalid_argument("allgather_2dmesh algorithm can't be used with this number of processes!");
133 my_row_base = (rank / Y) * Y;
134 my_col_base = rank % Y;
140 auto* req = new MPI_Request[num_reqs];
141 MPI_Request* req_ptr = req;
143 // do local allgather/local copy
144 recv_offset = rank * block_size;
145 Datatype::copy(send_buff, send_count, send_type, (char *)recv_buff + recv_offset,
146 recv_count, recv_type);
149 for (i = 0; i < Y; i++) {
150 src = i + my_row_base;
153 recv_offset = src * block_size;
154 *(req_ptr++) = Request::irecv((char *)recv_buff + recv_offset, recv_count, recv_type, src, tag,
159 for (i = 0; i < Y; i++) {
160 dst = i + my_row_base;
163 Request::send(send_buff, send_count, send_type, dst, tag, comm);
166 Request::waitall(Y - 1, req, MPI_STATUSES_IGNORE);
171 for (i = 0; i < X; i++) {
172 src = (i * Y + my_col_base);
175 src_row_base = (src / Y) * Y;
176 recv_offset = src_row_base * block_size;
177 *(req_ptr++) = Request::irecv((char *)recv_buff + recv_offset, recv_count * Y, recv_type, src, tag,
181 for (i = 0; i < X; i++) {
182 dst = (i * Y + my_col_base);
185 send_offset = my_row_base * block_size;
186 Request::send((char *)recv_buff + send_offset, send_count * Y, send_type, dst, tag,
190 Request::waitall(X - 1, req, MPI_STATUSES_IGNORE);
197 } // namespace simgrid::smpi