Mastodon Feed
Boosted by cstanhope@social.coop ("The Luddites were right"):
rygorous@mastodon.gamedev.place ("Fabian Giesen") wrote:
OK everyone on here and following me probably already knows this but I want to get it off my chest anyway:
*please* stop attributing reciprocal-square-root-by-IEEE-bit-twiddling to John Carmack/Quake 3.
John has a lot of "firsts" under his belt but this is not one of them.
This trick is _old_. The magic constant changes, but the trick itself is _old_.
1993 versions of Sun's fdlibm already included this reproduction of W. Kahan and K. C. Ng's paper on the subject: https://github.com/freemint/fdlibm/blob/master/e%5Fsqrt.c#L215