On Tuesday 01 February 2005 20:03, Timothy Miller wrote: > >>>Therein lies a problem. Since the reciprocal isn't precise (we use > >>>only 10 mantissa bits when computing it) > >> > >>Hmm, I thought we had 18 bits of precision readily available. Is this a > >>consequence of using linear interpolation for the divide? > > > > I was also under the impression that 10 mantissa bits were used for the > > LUT, and the other bits were used for linear interpolation between two 18 > > bit values from the LUT. > > I wasn't even going to bother with the interpolation. The reason is > that we have a limited number of RAM blocks and they're dual ported. If > we're going to properly compute every fragment (not estimate odd ones), > then we have to look up two reciprocals every cycle.
Erm, look up four reciprocals right? Two to interpolate between for the even fragment, and two for the odd fragment? And the RAM is dual ported, so you're two ports short? Lourens _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
