On Tue, 8 Feb 2005 09:28:50 -0500 Timothy Miller <[EMAIL PROTECTED]> wrote: >We need a table and an algorithm that produces good results. Even >with a fixed implementation, the table will be accessible in case >someone comes up with better numbers.
Hi everyone, Just as a remark: would it not be better to tabulate bits of x+0.5/x instead of 0.5/x itself. The range of 0.5/x in [0.5, 1) is (0.5, 1], while x+0.5/x is in [sqrt(2)=1.414..., 1.5]. Also, the derivative of 0.5/x lies between -2 and -0.5 in the given x-range, while the derivative of x+0.5/x lies between -1 and +0.5. I think it should therefore be possible to compute a few of the highest bits in random logic, and tabulate differences in a block-ram, with only one bit of overlap. The additional cost is of course that you have to subtract x from the result of the interpolation... Is there anything against using a block-ram in 36x512 mode as 12x1536? If the reciprocal is implemented with the first few bits computed in random logic, then 18 bits is overkill, but 9 bits is not enough. Just some ideas that popped up. Where's the catch? ;) Greetings, Alexander _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
