2021.01.10 13:36:43 (1348247397843968000) from Daniel J. Bernstein:
Now under 3900 Skylake cycles for code that seems to compute inverses mod 2^255-19: https://gcd.cr.yp.to/software.html This is further work with @bo_yin, also using ideas from Greg Maxwell and @pwuille. Still exploring speeds, still haven't verified the code, so don't put into production.