- MPI_Comm_rank(comm, &rank);
- MPI_Comm_size(comm, &num_procs);
- MPI_Type_extent(send_type, &extent);
+ rank = smpi_comm_rank(comm);
+ num_procs = smpi_comm_size(comm);
+
+ if((num_procs&(num_procs-1)))
+ THROWF(arg_error,0, "allgather pair algorithm can't be used with non power of two number of processes ! ");
+
+ extent = smpi_datatype_get_extent(send_type);