[squeak-dev] Posits
Tony Garnock-Jones
tonyg at leastfixedpoint.com
Mon Nov 14 09:22:34 UTC 2022
Here's a more up-to-date criticism:
https://hal.inria.fr/hal-01959581v2/document
Florent de Dinechin, Luc Forget, Jean-Michel Muller, Yohann Uguen.
Posits: the good, the bad and the ugly. 2018. hal-01959581v2
I still very much like the theory of posits, and their potential for use
as a storage format. What my reading over the last few days has taught
me, though, is that I'm not qualified to opine on their uses for
*computation*! They still seem really promising - it seems like they're
perhaps *usually* superior to floats for many numerical algorithms, but
not *always* superior? And you still have to do Proper Numerical
Analysis, just like with IEEE754. And since the standard posit formats
have a slightly smaller range of precisely-encoded contiguous integers
in them, maybe regular floats/doubles are better where you're doing
something shady like using them in place of a proper integer type
(*cough cough javascript*)...
On 11/11/22 09:42, Marcel Taeumel wrote:
> Hmm... Patrick just pointed out to me that this critique addresses Unum
> I. "Posits" are Unum III:
> https://en.wikipedia.org/wiki/Unum_(number_format)
> <https://en.wikipedia.org/wiki/Unum_(number_format)>
>
> Hmm...
>
> Best,
> Marcel
>>
>> Am 11.11.2022 04:34:31 schrieb Craig Latta <craig at blackpagedigital.com>:
>>
>>
>> This critique was interesting also, by William Kahan, the main
>> architect of the IEEE 754-1985 floating-point spec:
>>
>> https://people.eecs.berkeley.edu/~wkahan/UnumSORN.pdf
>>
>>
>> -C
>>
>> --
>> Craig Latta :: research computer scientist ::
>> Black Page Digital :: Berkeley, California ::
>> 663137D7940BF5C0AF :: C1349FB2ADA32C4D5314CE ::
>>
>>
>>
>>
>
>
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