3 ms·
Posits are pretty damn cool. The posit standard was ratified in March this year. It's only 12 pages and shockingly comprehensible for a standard document: http
by infogulch 4y ago
Posits are pretty damn cool.
The posit standard was ratified in March this year. It's only 12 pages and shockingly comprehensible for a standard document: https://posithub.org/docs/posit_standard-2.pdf https://posithub.org/docs/posit_standard-2.pdf
Also in March Gustafson hosted the Conference for Next Generation Arithmetic (CoNGA) 2022 sorta 'inside' the Supercomputing Asia (SCA2022) conference. They covered a bunch of different areas not exclusively related to posits. Lots of cool topics including hardware implementations and optimizations, comparisons between different number formats, and a talk and panel from the posit committee about writing the standard and what's next for posits. The session videos are somewhat difficult to find so I made a playlist: https://youtube.com/playlist?list=PLBH9oUUfaYoQNl6-zr_ScsMp4ZFQrG9TE https://youtube.com/playlist?list=PLBH9oUUfaYoQNl6-zr_ScsMp4... (Note the descriptions have talk titles and authors.)
The best video intro to posits is probably the one in 2019: https://www.youtube.com/watch?v=JJgT-YphE1Y https://www.youtube.com/watch?v=JJgT-YphE1Y
- infogulch 4y agoProbably my favorite CoNGA2022 talk is the first one, A Case for Correctly Rounded Elementary Functions (starts at about 10m), which presents a methodology and library, already implemented into LLVM for floats, of elementary functions (lg, sin, cos, etc etc) that are 1. correctly rounded to the last bit, 2. are faster than the previous algorithms, 3. and can be downcasted to any smaller format while preserving correct rounding. The posit standard requires correctly rounded elementary functions in order for an implementation to be considered compliant. This means that every standards-compliant posit implementation is now also deterministic.