add scatter algos from ompi

[simgrid.git] / src / smpi / colls / allgather-2dmesh.c

diff --git a/src/smpi/colls/allgather-2dmesh.c b/src/smpi/colls/allgather-2dmesh.c
index b5f5042..4e3a9c7 100644 (file)
--- a/src/smpi/colls/allgather-2dmesh.c
+++ b/src/smpi/colls/allgather-2dmesh.c
@@ -119,7 +119,9 @@ smpi_coll_tuned_allgather_2dmesh(void *send_buff, int send_count, MPI_Datatype
 
   block_size = extent * send_count;
 
-  is_2dmesh(num_procs, &X, &Y);
+  if (!is_2dmesh(num_procs, &X, &Y))
+    return MPI_ERR_COMM;
+
   my_row_base = (rank / Y) * Y;
   my_col_base = rank % Y;