MPI_SGE_LENGTH
#define MPI_SGE_SET_FLAGS_LENGTH(f,l) (MPI_SGE_SET_FLAGS(f) | MPI_SGE_LENGTH(l))
#define MPI_pSGE_GET_LENGTH(psg) MPI_SGE_LENGTH((psg)->FlagsLength)
#define MPI_pSGE_SET_LENGTH(psg,l) (psg)->FlagsLength |= MPI_SGE_LENGTH(l)