X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/3d25ce2fc68666d4b674c4f710cde362aa584632..d53d00d608a60a6f05e77ea7b7cd5c4e544d7ab1:/src/smpi/colls/alltoall-pair-one-barrier.cpp

diff --git a/src/smpi/colls/alltoall-pair-one-barrier.cpp b/src/smpi/colls/alltoall-pair-one-barrier.cpp
new file mode 100644
index 0000000000..a0ac128d98
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+++ b/src/smpi/colls/alltoall-pair-one-barrier.cpp
@@ -0,0 +1,65 @@
+/* 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"
+/*****************************************************************************
+
+ * Function: alltoall_pair
+
+ * Return: int
+
+ * Inputs:
+    send_buff: send input buffer
+    send_count: number of elements to send
+    send_type: data type of elements being sent
+    recv_buff: receive output buffer
+    recv_count: number of elements to received
+    recv_type: data type of elements being received
+    comm: communicator
+
+ * Descrp: Function works when P is power of two. In each phase of P - 1
+           phases, nodes in pair communicate their data.
+
+ * Auther: Ahmad Faraj
+
+ ****************************************************************************/
+int
+smpi_coll_tuned_alltoall_pair_one_barrier(void *send_buff, int send_count,
+                                          MPI_Datatype send_type,
+                                          void *recv_buff, int recv_count,
+                                          MPI_Datatype recv_type, MPI_Comm comm)
+{
+
+  MPI_Aint send_chunk, recv_chunk;
+  MPI_Status s;
+  int i, src, dst, rank, num_procs;
+  int tag = COLL_TAG_ALLTOALL;
+
+  char *send_ptr = (char *) send_buff;
+  char *recv_ptr = (char *) recv_buff;
+
+  rank = smpi_comm_rank(comm);
+  num_procs = smpi_comm_size(comm);
+
+  if((num_procs&(num_procs-1)))
+    THROWF(arg_error,0, "alltoall pair algorithm can't be used with non power of two number of processes ! ");
+
+  send_chunk = smpi_datatype_get_extent(send_type);
+  recv_chunk = smpi_datatype_get_extent(recv_type);
+
+  send_chunk *= send_count;
+  recv_chunk *= recv_count;
+
+  mpi_coll_barrier_fun(comm);
+  for (i = 0; i < num_procs; i++) {
+    src = dst = rank ^ i;
+    smpi_mpi_sendrecv(send_ptr + dst * send_chunk, send_count, send_type, dst,
+                 tag, recv_ptr + src * recv_chunk, recv_count, recv_type,
+                 src, tag, comm, &s);
+  }
+
+  return MPI_SUCCESS;
+}