Julia EvansFeb 10, 2023
floating point representation
Show threadNathan StocksFeb 10, 2023

@b0rk Ooo, can you do one for posits?

https://www.sigarch.org/posit-a-potential-replacement-for-ieee-754/

Posit: A Potential Replacement for IEEE 754

Motivation Number systems and computer arithmetics are essential for designing efficient hardware and software architecture. In particular, real-valued computation constitutes a crucial component i…

SIGARCH
Show threadJulia EvansFeb 10, 2023
@nathanstocks AFAIK nobody (or almost nobody) uses posits, I only write about things that are very commonly used :)
Show threadNathan Stocks
@b0rk Well, dang. Posits are super awesome, and we're only not using them due to inertia. 😢
Feb 10, 2023 at 5:50pmWeb
Show threadJulia EvansFeb 10, 2023
@nathanstocks that could be true! it's just not what I do here -- I explain how computers work today, not theorize about potential futures :)
Show threadI Can't Believe It's Not Zero!Feb 10, 2023
@nathanstocks @b0rk that is a pretty strong exaggeration. We don’t use posits partially because of inertia, but also because they aren’t really any better than IEEE floats, and they’re also worse in some important ways.
Show threadNathan StocksFeb 10, 2023
@steve @b0rk Oh! I didn't know that. I should read up some more, then. All that I've read to date was glowing recommendations for it.
Show threadJulia EvansFeb 10, 2023
@nathanstocks @steve there's a subthread here talking about some criticisms (if you scroll down) https://social.jvns.ca/@kelpana@mastodon.ie/109835299704305047
Alanna (@[email protected])

@[email protected] The "Posits": https://en.wikipedia.org/wiki/Unum_(number_format)

mastodon.ie
Show threadNathan StocksFeb 10, 2023
@b0rk @steve Cool, thank you! Such a recent thread, too. I wish I had caught it in the first place. Sorry for the noise!
Show thread∴ esoterik ∴Feb 10, 2023

@nathanstocks @steve @b0rk also worth noting that over the last 8 years there have been 3 different versions:

https://en.wikipedia.org/wiki/Unum_(number_format)

so if you had moved to type II posits (say) you'd have to migrate again. i would stay away unless you're interesting in doing your own evaluation and implementation.

Unum (number format) - Wikipedia

Show threadMarc B. ReynoldsFeb 10, 2023
@nathanstocks @b0rk Posits are a scam. I've never read papers more disingenuous in my entire life.
Show threadNathan StocksFeb 10, 2023
@mbr @b0rk I’ve learned a lot from these sub threads! This paper someone linked to seems to be a pretty thorough look at the pros and cons. Posits are definitely not as advantageous as I was led to believe. Rather there are a bunch of trade offs, like many things in life. https://people.eecs.berkeley.edu/~demmel/ma221_Fall20/Dinechin_etal_2019.pdf
Show threadJulesFeb 10, 2023
@nathanstocks @b0rk Posits don't live up to the hype, and the posit interval arithmetic proposal was downright broken. The primary thing posits are good at is marketing.