X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/e6557f5a455aa071d62f977185ea49ed1437003a..b108a4b307246fd04e52827319b4a522e414c51f:/src/smpi/colls/barrier-ompi.c

diff --git a/src/smpi/colls/barrier-ompi.c b/src/smpi/colls/barrier-ompi.c
index ad5b748042..39bdeb101c 100644
--- a/src/smpi/colls/barrier-ompi.c
+++ b/src/smpi/colls/barrier-ompi.c
@@ -52,8 +52,8 @@ int smpi_coll_tuned_barrier_ompi_doublering(MPI_Comm comm
     size = smpi_comm_size(comm);
 
     XBT_DEBUG("ompi_coll_tuned_barrier_ompi_doublering rank %d", rank);
-  
-    left = ((rank-1)%size);
+
+    left = ((rank-1+size)%size);
     right = ((rank+1)%size);
 
     if (rank > 0) { /* receive message from the left */