1 /* Copyright (c) 2013-2019. 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"
8 //#include <star-reduction.c>
12 // this requires that count >= NP
13 int allreduce__rab2(const void *sbuff, void *rbuff,
14 int count, MPI_Datatype dtype,
15 MPI_Op op, MPI_Comm comm)
19 int nbytes, send_size, s_offset, r_offset;
21 #ifdef MPICH2_REDUCTION
22 MPI_User_function * uop = MPIR_Op_table[op % 16 - 1];
24 MPI_User_function *uop;
26 op_ptr = MPIR_ToPointer(op);
31 nprocs = comm->size();
34 s_extent = dtype->get_extent();
41 send_size = (count + nprocs) / nprocs;
42 nbytes = send_size * s_extent;
44 unsigned char* send = smpi_get_tmp_sendbuffer(s_extent * send_size * nprocs);
45 unsigned char* recv = smpi_get_tmp_recvbuffer(s_extent * send_size * nprocs);
46 unsigned char* tmp = smpi_get_tmp_sendbuffer(nbytes);
48 memcpy(send, sbuff, s_extent * count);
50 Colls::alltoall(send, send_size, dtype, recv, send_size, dtype, comm);
52 memcpy(tmp, recv, nbytes);
54 for (i = 1, s_offset = nbytes; i < nprocs; i++, s_offset = i * nbytes)
55 if (op != MPI_OP_NULL)
56 op->apply(recv + s_offset, tmp, &send_size, dtype);
58 Colls::allgather(tmp, send_size, dtype, recv, send_size, dtype, comm);
59 memcpy(rbuff, recv, count * s_extent);
61 smpi_free_tmp_buffer(recv);
62 smpi_free_tmp_buffer(tmp);
63 smpi_free_tmp_buffer(send);
65 const void* send = sbuff;
66 send_size = count / nprocs;
67 nbytes = send_size * s_extent;
68 r_offset = rank * nbytes;
70 unsigned char* recv = smpi_get_tmp_recvbuffer(s_extent * send_size * nprocs);
72 Colls::alltoall(send, send_size, dtype, recv, send_size, dtype, comm);
74 memcpy((char *) rbuff + r_offset, recv, nbytes);
76 for (i = 1, s_offset = nbytes; i < nprocs; i++, s_offset = i * nbytes)
77 if (op != MPI_OP_NULL)
78 op->apply(recv + s_offset, static_cast<char*>(rbuff) + r_offset, &send_size, dtype);
80 Colls::allgather((char *) rbuff + r_offset, send_size, dtype, rbuff, send_size,
82 smpi_free_tmp_buffer(recv);