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From: "Keith Packard" <keithp@keithp.com>
To: Paul Zimmermann <Paul.Zimmermann@inria.fr>
Cc: newlib@sourceware.org
Subject: Re: issue with tgammaf
Date: Wed, 16 Sep 2020 08:13:58 -0700	[thread overview]
Message-ID: <87sgbheouh.fsf@keithp.com> (raw)
In-Reply-To: <mw7dsuxgrj.fsf@tomate.loria.fr>

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Paul Zimmermann <Paul.Zimmermann@inria.fr> writes:

> thank you Keith. For your information I have updated my comparison with
> Newlib 3.3.0:
>
> https://members.loria.fr/PZimmermann/papers/accuracy.pdf
>
> The differences with the previous (unknown) version of Newlib I used are
> that j1 is less accurate (largest error goes from 2.66e6 ulps to 1.68e7 ulps),
> and y1 is more accurate (largest error goes from 4.65e8 ulps to 6.18e6 ulps).
> (However, those huge errors simply tell us that j1f is completely off, in the
> first case for x=0x6.cfd78p+100 j1f returns 0 instead of -0x1p-52.)
>
> I am still unable to compile a program using lgammaf:

You might have more luck with lgammaf_r as that avoids use of
_impure_ptr in newlib.

Alternatively, you can use the picolibc fork of newlib which uses native
thread local storage instead of a giant struct full of library global
data. That has built-in support for compiling on x86_64 for testing.

-- 
-keith

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  reply	other threads:[~2020-09-16 15:14 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-15  8:21 Paul Zimmermann
2020-09-15 17:28 ` Keith Packard
2020-09-16  8:33   ` Paul Zimmermann
2020-09-16 15:13     ` Keith Packard [this message]
2020-09-17  7:18       ` Paul Zimmermann
2020-09-17 16:11         ` Keith Packard
2021-01-13  5:46           ` Paul Zimmermann
2021-01-13  6:38             ` Keith Packard
2021-01-13  7:52               ` Paul Zimmermann
2020-09-18 21:21   ` Jeff Johnston

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