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From: minforth <minforth@gmx.net>
Newsgroups: comp.lang.forth
Subject: Re: Parsing timestamps?
Date: Thu, 10 Jul 2025 23:16:27 +0200
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Am 10.07.2025 um 21:33 schrieb Paul Rubin:
> anton@mips.complang.tuwien.ac.at (Anton Ertl) writes:
>>> I believes IEEE specifies both 80 bit and 128 bit formats in addition
>>> to 64 bit.
>> Not 80-bit format.  binary128 and binary256 are specified.
> 
> I see, 80 bits is considered double-extended.  "The x87 and Motorola
> 68881 80-bit formats meet the requirements of the IEEE 754-1985 double
> extended format,[12] as does the IEEE 754 128-bit binary format."
> (https://en.wikipedia.org/wiki/Extended_precision)
> 
> Interestingly, Kahan's 1997 report on IEEE 754's status does say 80 bit
> is specified.  But it sounds like that omits some nuance.
> 
> https://people.eecs.berkeley.edu/~wkahan/ieee754status/IEEE754.PDF

Kahan was also overly critical of dynamic Unum/Posit formats.

Time has shown that he was partially wrong:
https://spectrum.ieee.org/floating-point-numbers-posits-processor