XR_O0
rd_num - R_O0 + XR_O0] << 32;
xregs->pr_un.pr_v8p.pr_xo[XR_O0] = GET_UPPER_32(rp->r_o0);
rp->r_o0 = SET_ALL_64(xregs->pr_un.pr_v8p.pr_xo[XR_O0], rp->r_o0);