Merge branch 'master' of git+ssh://scm.gforge.inria.fr//gitroot/simgrid/simgrid

[simgrid.git] / src / smpi / colls / allgather-rhv.c

diff --git a/src/smpi/colls/allgather-rhv.c b/src/smpi/colls/allgather-rhv.c
index c3db821..3aaf479 100644 (file)
--- a/src/smpi/colls/allgather-rhv.c
+++ b/src/smpi/colls/allgather-rhv.c
@@ -1,3 +1,9 @@
+/* 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"
 
 // now only work with power of two processes
@@ -14,14 +20,17 @@ smpi_coll_tuned_allgather_rhv(void *sbuf, int send_count,
   // local int variables
   int i, dst, send_base_offset, recv_base_offset, send_chunk, recv_chunk,
       send_offset, recv_offset;
-  int rank, num_procs;
-  int tag = 50;
+  int tag = COLL_TAG_ALLGATHER;
   int mask;
   int curr_count;
 
   // get size of the communicator, followed by rank 
-  num_procs = smpi_comm_size(comm);
-  rank = smpi_comm_rank(comm);
+  unsigned int num_procs = smpi_comm_size(comm);
+
+  if((num_procs&(num_procs-1)))
+    THROWF(arg_error,0, "allgather rhv algorithm can't be used with non power of two number of processes ! ");
+
+  unsigned int rank = smpi_comm_rank(comm);
 
   // get size of single element's type for send buffer and recv buffer
   s_extent = smpi_datatype_get_extent(send_type);