Re: [RFC][PATCH] NTP shift_right cleanup (v. A1)

[john stultz <johnstul@us.ibm.com>]

On Wed, 2005-09-14 at 20:13 +0200, Roman Zippel wrote:
> > @@ -792,13 +769,8 @@ static void update_wall_time_one_tick(vo
> >  	 * advance the tick more.
> >  	 */
> >  	time_phase += time_adj;
> > -	if (time_phase <= -FINENSEC) {
> > -		long ltemp = -time_phase >> (SHIFT_SCALE - 10);
> > -		time_phase += ltemp << (SHIFT_SCALE - 10);
> > -		delta_nsec -= ltemp;
> > -	}
> > -	else if (time_phase >= FINENSEC) {
> > -		long ltemp = time_phase >> (SHIFT_SCALE - 10);
> > +	if (abs(time_phase) >= FINENSEC) {
> > +		long ltemp = shift_right(time_phase, (SHIFT_SCALE - 10));
> >  		time_phase -= ltemp << (SHIFT_SCALE - 10);
> >  		delta_nsec += ltemp;
> >  	}
> 
> I checked and this actually generates worse code.

Well, if I drop the abs() and use:
	if ((time_phase >= FINENSEC) || (time_phase <= -FINENSEC))

It looks pretty close in my test. Is that cool with you?

thanks
-john


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