SET_LOW_WORD
SET_LOW_WORD(df,0);
SET_LOW_WORD(w,0);
SET_LOW_WORD(t1,0);
SET_LOW_WORD(s_h,0);
SET_LOW_WORD(t_h,0);
SET_LOW_WORD(p_h,0);
SET_LOW_WORD(t1,0);
SET_LOW_WORD(yy1,0);
SET_LOW_WORD(t,0);
SET_LOW_WORD(z,low);
SET_LOW_WORD(z, 0);
SET_LOW_WORD(t, 0);
SET_LOW_WORD(z, 0);
SET_LOW_WORD(t, 0);
SET_LOW_WORD(*_dp, _lw & 0xf8000000);
SET_LOW_WORD(z,0);
SET_LOW_WORD(z,0);