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From: tmoran@bix.com (Tom Moran)
Subject: Re: fixed point vs floating point
Date: 1997/11/23
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Newsgroups: comp.lang.ada,sci.math.num-analysis
Date: 1997-11-23T00:00:00+00:00
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>Converting a fixed point value to fpt, issue the sinus instruction
>and convert it back is much faster than even thinking about doing it in
>fixed point. ;-)
But "type degrees is delta 1.0/16 range 0.0 .. 360.0;" has only 5760
possible values, and a table lookup with a table of 5760 entries is
often quite reasonable, and surely faster than converting to fp,
calculating a sin, and converting back.  Not to mention if the
function is not just sin, but, say the 6th power of the cos (in a
Phong illumination calculation, say).
  I can't seem to find my Cody&Waite, but I think they give fixed
point algorithms, and I also think I've seen mention of Ada code for
it in the PAL or some such public place.