_R_S5
uc.uc_mcontext.__gregs[_REG_S5] = sc->sc_regs[_R_S5];
{ "s5", (long *)&ddb_regs.r_regs[_R_S5], DB_SETF_REGS, NULL },
gdb_regs[21] = regs->r_regs[_R_S5]; /* S5 */
case _R_S5: /* s5 */
tf->tf_regs[_R_S3], tf->tf_regs[_R_S4], tf->tf_regs[_R_S5]);