[HN Gopher] Revisiting the Fast Inverse Square Root - Is It Stil... ___________________________________________________________________ Revisiting the Fast Inverse Square Root - Is It Still Useful? Author : nhellman Score : 15 points Date : 2023-04-20 21:05 UTC (1 hours ago) (HTM) web link (hllmn.net) (TXT) w3m dump (hllmn.net) | thegeomaster wrote: | One important point that the article doesn't touch on is | determinism. rsqrtps is implemented differently on different | CPUs, and so if having reproducible floating point results is a | requirement (there's a lot of use-cases for this), you simply | cannot use it. Your only remaining option is to use a totally | IEEE-754 compliant algorithm that is guaranteed to work the same | on every CPU that implements IEEE-754 floats, and for that | there's still no better approach than using the Q_rsqrt idea, of | course with some modifications for the "modern age". ___________________________________________________________________ (page generated 2023-04-20 23:01 UTC)