mpihelp_sub_n
mpihelp_sub_n(wp, vp, up, usize);
mpihelp_sub_n(wp, up, vp, usize);
cy = mpihelp_sub_n(res_ptr, s1_ptr, s2_ptr, s2_size);
mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
mpihelp_sub_n(np, np, dp, dsize);
mpihelp_sub_n(prodp, up + hsize, up, hsize);
mpihelp_sub_n(prodp, up, up + hsize, hsize);
mpihelp_sub_n(prodp + hsize, vp + hsize, vp, hsize);
mpihelp_sub_n(prodp + hsize, vp, vp + hsize, hsize);
mpihelp_sub_n(prodp + hsize, prodp + hsize, tspace,
mpihelp_sub_n(prodp, up + hsize, up, hsize);
mpihelp_sub_n(prodp, up, up + hsize, hsize);
cy -= mpihelp_sub_n(prodp + hsize, prodp + hsize, tspace, size);