int Coll_reduce_scatter_gather::reduce(void *sendbuf, void *recvbuf,
int count, MPI_Datatype datatype,
MPI_Op op, int root, MPI_Comm comm)
int Coll_reduce_scatter_gather::reduce(void *sendbuf, void *recvbuf,
int count, MPI_Datatype datatype,
MPI_Op op, int root, MPI_Comm comm)