protect (hopefully) collective communication algorithms from abuse.

[simgrid.git] / src / smpi / colls / alltoall-pair-mpi-barrier.c

diff --git a/src/smpi/colls/alltoall-pair-mpi-barrier.c b/src/smpi/colls/alltoall-pair-mpi-barrier.c
index f12c3f9..1816cff 100644 (file)
--- a/src/smpi/colls/alltoall-pair-mpi-barrier.c
+++ b/src/smpi/colls/alltoall-pair-mpi-barrier.c
@@ -30,12 +30,16 @@ smpi_coll_tuned_alltoall_pair_mpi_barrier(void *send_buff, int send_count,
   MPI_Status s;
   MPI_Aint send_chunk, recv_chunk;
   int i, src, dst, rank, num_procs;
-  int tag = 101;
+  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);
 
@@ -44,7 +48,7 @@ smpi_coll_tuned_alltoall_pair_mpi_barrier(void *send_buff, int send_count,
 
   for (i = 0; i < num_procs; i++) {
     src = dst = rank ^ i;
-    smpi_mpi_barrier(comm);
+    mpi_coll_barrier_fun(comm);
     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);