1 /* Copyright (c) 2013-2023. 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 /*****************************************************************************
53 * Function: allgather_bruck
56 * send_buff: send input buffer
57 * send_count: number of elements to send
58 * send_type: data type of elements being sent
59 * recv_buff: receive output buffer
60 * recv_count: number of elements to received
61 * recv_type: data type of elements being received
63 * Descrp: Function realizes the allgather operation using the bruck
66 * Comment: Original bruck algorithm from MPICH is slightly modified by
68 ****************************************************************************/
70 namespace simgrid::smpi {
72 int allgather__bruck(const void *send_buff, int send_count,
73 MPI_Datatype send_type, void *recv_buff,
74 int recv_count, MPI_Datatype recv_type,
81 // local int variables
82 int src, dst, rank, num_procs, count, remainder;
83 int tag = COLL_TAG_ALLGATHER;
86 // local string variables
87 char *send_ptr = (char *) send_buff;
88 char *recv_ptr = (char *) recv_buff;
90 // get size of the communicator, followed by rank
91 num_procs = comm->size();
94 // get size of single element's type for recv buffer
95 recv_extent = recv_type->get_extent();
99 unsigned char* tmp_buff = smpi_get_tmp_sendbuffer(num_procs * recv_count * recv_extent);
101 // perform a local copy
102 Datatype::copy(send_ptr, send_count, send_type, tmp_buff, recv_count, recv_type);
103 while (pof2 <= (num_procs / 2)) {
104 src = (rank + pof2) % num_procs;
105 dst = (rank - pof2 + num_procs) % num_procs;
107 Request::sendrecv(tmp_buff, count, recv_type, dst, tag,
108 tmp_buff + count * recv_extent, count, recv_type,
109 src, tag, comm, &status);
114 remainder = num_procs - pof2;
116 src = (rank + pof2) % num_procs;
117 dst = (rank - pof2 + num_procs) % num_procs;
119 Request::sendrecv(tmp_buff, remainder * recv_count, recv_type, dst, tag,
120 tmp_buff + count * recv_extent, remainder * recv_count,
121 recv_type, src, tag, comm, &status);
124 Request::sendrecv(tmp_buff, (num_procs - rank) * recv_count, recv_type, rank,
125 tag, recv_ptr + rank * recv_count * recv_extent,
126 (num_procs - rank) * recv_count, recv_type, rank, tag, comm,
130 Request::sendrecv(tmp_buff + (num_procs - rank) * recv_count * recv_extent,
131 rank * recv_count, recv_type, rank, tag, recv_ptr,
132 rank * recv_count, recv_type, rank, tag, comm, &status);
133 smpi_free_tmp_buffer(tmp_buff);
137 } // namespace simgrid::smpi