avoid warning by checking index in the right order

[simgrid.git] / src / smpi / colls / reduce_scatter-ompi.c

diff --git a/src/smpi/colls/reduce_scatter-ompi.c b/src/smpi/colls/reduce_scatter-ompi.c
index bb01dee..1f3175b 100644 (file)
--- a/src/smpi/colls/reduce_scatter-ompi.c
+++ b/src/smpi/colls/reduce_scatter-ompi.c
@@ -1,4 +1,9 @@
-/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
+/* 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. */
+
 /*
  * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
  *                         University Research and Technology
@@ -12,11 +17,8 @@
  *                         All rights reserved.
  * Copyright (c) 2008      Sun Microsystems, Inc.  All rights reserved.
  * Copyright (c) 2009      University of Houston. All rights reserved.
- * $COPYRIGHT$
  *
  * Additional copyrights may follow
- *
- * $HEADER$
  */
 
 #include "colls_private.h"
@@ -59,6 +61,8 @@ smpi_coll_tuned_reduce_scatter_ompi_basic_recursivehalving(void *sbuf,
     size = smpi_comm_size(comm);
    
     XBT_DEBUG("coll:tuned:reduce_scatter_ompi_basic_recursivehalving, rank %d", rank);
+    if(!smpi_op_is_commute(op))
+      THROWF(arg_error,0, " reduce_scatter ompi_basic_recursivehalving can only be used for commutative operations! ");
 
     /* Find displacements and the like */
     disps = (int*) xbt_malloc(sizeof(int) * size);