On Fri, 04 Feb 2005 17:47:13 +0100, Johannes Berg <[EMAIL PROTECTED]> wrote: > On Fr, 2005-02-04 at 11:10 -0500, Timothy Miller wrote: > > I've been coding the adder I'm working on to have a true zero. Logic > > detects that the exponent is zero (meaning something like 2^-127, I > > think) and doing the appropriate thing to make it a true zero. > > > > But I'm wondering if I can't just do away with that. 2^-127 is so > > small that any time it gets converted to integer or added to a larger > > number, it really does become zero. In fact, I'm not sure I can come > > up with a situation where not explicitly making that zero does any > > harm. > > > > Comments? > > What if you're adding 0 (2^-127) and 2^-120? That won't be equal to > 2^-120 since (I guess) you have more than 7 bits of precision. What if > then, the result is multiplied? > > Well, maybe you should read this mail as: consider what the output is > used for. If it doesn't go into a multiplier, you should be fine.
Yes, that is a good point. The problem case is if you're multiplying a really big number by a really small number. That could, theoretically, put you back into range of whatever clamping happens later and cause a problem. _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
