+++ /dev/null
-/* Copyright (c) 2013-2014. The SimGrid Team.
- * All rights reserved. */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-#include "colls_private.h"
-//#include <star-reduction.c>
-
-int smpi_coll_tuned_allreduce_rdb(void *sbuff, void *rbuff, int count,
- MPI_Datatype dtype, MPI_Op op, MPI_Comm comm)
-{
- int nprocs, rank, tag = COLL_TAG_ALLREDUCE;
- int mask, dst, pof2, newrank, rem, newdst;
- MPI_Aint extent, lb;
- MPI_Status status;
- void *tmp_buf = NULL;
- /*
- #ifdef MPICH2_REDUCTION
- MPI_User_function * uop = MPIR_Op_table[op % 16 - 1];
- #else
- MPI_User_function *uop;
- struct MPIR_OP *op_ptr;
- op_ptr = MPIR_ToPointer(op);
- uop = op_ptr->op;
- #endif
- */
- nprocs=comm->size();
- rank=comm->rank();
-
- dtype->extent(&lb, &extent);
- tmp_buf = (void *) smpi_get_tmp_sendbuffer(count * extent);
-
- Request::sendrecv(sbuff, count, dtype, rank, 500,
- rbuff, count, dtype, rank, 500, comm, &status);
-
- // find nearest power-of-two less than or equal to comm_size
- pof2 = 1;
- while (pof2 <= nprocs)
- pof2 <<= 1;
- pof2 >>= 1;
-
- rem = nprocs - pof2;
-
- // In the non-power-of-two case, all even-numbered
- // processes of rank < 2*rem send their data to
- // (rank+1). These even-numbered processes no longer
- // participate in the algorithm until the very end. The
- // remaining processes form a nice power-of-two.
-
- if (rank < 2 * rem) {
- // even
- if (rank % 2 == 0) {
-
- Request::send(rbuff, count, dtype, rank + 1, tag, comm);
-
- // temporarily set the rank to -1 so that this
- // process does not pariticipate in recursive
- // doubling
- newrank = -1;
- } else // odd
- {
- Request::recv(tmp_buf, count, dtype, rank - 1, tag, comm, &status);
- // do the reduction on received data. since the
- // ordering is right, it doesn't matter whether
- // the operation is commutative or not.
- if(op!=MPI_OP_NULL) op->apply( tmp_buf, rbuff, &count, dtype);
-
- // change the rank
- newrank = rank / 2;
- }
- }
-
- else // rank >= 2 * rem
- newrank = rank - rem;
-
- // If op is user-defined or count is less than pof2, use
- // recursive doubling algorithm. Otherwise do a reduce-scatter
- // followed by allgather. (If op is user-defined,
- // derived datatypes are allowed and the user could pass basic
- // datatypes on one process and derived on another as long as
- // the type maps are the same. Breaking up derived
- // datatypes to do the reduce-scatter is tricky, therefore
- // using recursive doubling in that case.)
-
- if (newrank != -1) {
- mask = 0x1;
- while (mask < pof2) {
- newdst = newrank ^ mask;
- // find real rank of dest
- dst = (newdst < rem) ? newdst * 2 + 1 : newdst + rem;
-
- // Send the most current data, which is in recvbuf. Recv
- // into tmp_buf
- Request::sendrecv(rbuff, count, dtype, dst, tag, tmp_buf, count, dtype,
- dst, tag, comm, &status);
-
- // tmp_buf contains data received in this step.
- // recvbuf contains data accumulated so far
-
- // op is commutative OR the order is already right
- // we assume it is commuttive op
- // if (op -> op_commute || (dst < rank))
- if ((dst < rank)) {
- if(op!=MPI_OP_NULL) op->apply( tmp_buf, rbuff, &count, dtype);
- } else // op is noncommutative and the order is not right
- {
- if(op!=MPI_OP_NULL) op->apply( rbuff, tmp_buf, &count, dtype);
-
- // copy result back into recvbuf
- Request::sendrecv(tmp_buf, count, dtype, rank, tag, rbuff, count,
- dtype, rank, tag, comm, &status);
- }
- mask <<= 1;
- }
- }
- // In the non-power-of-two case, all odd-numbered processes of
- // rank < 2 * rem send the result to (rank-1), the ranks who didn't
- // participate above.
-
- if (rank < 2 * rem) {
- if (rank % 2) // odd
- Request::send(rbuff, count, dtype, rank - 1, tag, comm);
- else // even
- Request::recv(rbuff, count, dtype, rank + 1, tag, comm, &status);
- }
-
- smpi_free_tmp_buffer(tmp_buf);
- return MPI_SUCCESS;
-}
