public inbox for libc-alpha@sourceware.org
 help / color / mirror / Atom feed
From: Alejandro Colomar <alx@kernel.org>
To: Morten Welinder <mwelinder@gmail.com>
Cc: linux-man@vger.kernel.org, libc-alpha@sourceware.org,
	jsm-csl@polyomino.org.uk, newbie-02@gmx.de
Subject: Re: Man page issues: logb, significand, cbrt, log2, log10, exp10
Date: Sun, 3 Mar 2024 03:21:26 +0100	[thread overview]
Message-ID: <ZePerBa3QAvoFVSR@debian> (raw)
In-Reply-To: <CANv4PNm0xvB-GVb+z1yXPRVfeZYHU9533+VRTQfysjaycSbHBw@mail.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 985 bytes --]

Hi Morten,

On Sat, Mar 02, 2024 at 09:02:24PM -0500, Morten Welinder wrote:
> Thanks.
> 
> There is (was?) already crlibm out there.
> https://core-math.gitlabpages.inria.fr/  No particular need for wheel
> reinvention here.

crlibm doesn't seem to exist anymore.  Maybe just add some headers to
core-math, and package it as a standalone library.

> FWIW, it appears that the author of the glibc exp10 implementation
> agrees with me that the implementation is sub-standard:
> 
> https://codebrowser.dev/glibc/glibc/math/e_exp10.c.html
> 
> /* This is a very stupid and inprecise implementation. It'll get
> replaced sometime (soon?). */
> return __ieee754_exp (M_LN10 * arg);

Hmmm.  Still, it's simple.  If pow(10, x) is strictly better, maybe one
can prove it and send a patch.  Or for something better, it'll take more
work.


Have a lovely night!
Alex

-- 
<https://www.alejandro-colomar.es/>
Looking for a remote C programming job at the moment.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

  reply	other threads:[~2024-03-03  2:21 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CANv4PNkVv_0eLgiSP3L_KfC-eZJaVLZ5AP1AGfD0GNrR5M4Hrg@mail.gmail.com>
     [not found] ` <ZeEnJB96mMC5bfBz@debian>
     [not found]   ` <CANv4PNmMpiwfv5acr7U6VEVe7PE_AMTzkkpNoNN9jrtVzk_93Q@mail.gmail.com>
2024-03-02 21:54     ` Alejandro Colomar
2024-03-03  2:02       ` Morten Welinder
2024-03-03  2:21         ` Alejandro Colomar [this message]
2024-03-03 11:46           ` Vincent Lefevre
2024-03-03 12:21             ` Alejandro Colomar
2024-03-03 22:26               ` Morten Welinder
2024-03-04 12:17         ` Adhemerval Zanella Netto
2024-03-05 16:12 ` [PATCH v2 0/3] manual/math.texi: logb(3) and cbrt(3) fixes Alejandro Colomar
2024-03-05 16:12   ` [PATCH v2 1/3] manual: logb(x) is floor(log2(fabs(x))) Alejandro Colomar
2024-03-29 22:08     ` DJ Delorie
2024-03-29 23:00       ` Alejandro Colomar
2024-03-05 16:12   ` [PATCH v2 2/3] manual: floor(log2(fabs(x))) has rounding errors Alejandro Colomar
2024-03-30  0:24     ` DJ Delorie
2024-03-30  9:27       ` Alejandro Colomar
2024-03-30  9:30         ` Alejandro Colomar
2024-03-30  9:47       ` Andreas Schwab
2024-03-05 16:12   ` [PATCH v2 3/3] manual: Cube roots are rarely representable Alejandro Colomar
2024-03-30  0:27     ` DJ Delorie
2024-03-30  7:07       ` Paul Zimmermann
2024-03-30 16:51         ` DJ Delorie
2024-03-30 18:42           ` Alejandro Colomar
2024-03-30 18:50             ` DJ Delorie
2024-03-30 19:07               ` Alejandro Colomar
2024-03-31 20:38   ` [PATCH v3 0/4] manual: arith.texi and math.texi fixes Alejandro Colomar
2024-03-31 20:38     ` [PATCH v3 1/4] manual: logb(x) is floor(log2(fabs(x))) Alejandro Colomar
2024-03-31 20:38     ` [PATCH v3 2/4] manual: floor(log2(fabs(x))) has rounding errors Alejandro Colomar
2024-03-31 20:38     ` [PATCH v3 3/4] manual: Clarify return value of cbrt(3) Alejandro Colomar
2024-04-01 18:57       ` DJ Delorie
2024-03-31 20:38     ` [PATCH v3 4/4] manual: significand() uses FLT_RADIX, not 2 Alejandro Colomar
2024-04-01 19:09       ` DJ Delorie
2024-03-04 15:29 Man page issues: logb, significand, cbrt, log2, log10, exp10 Wilco Dijkstra
2024-03-05  8:14 ` Paul Zimmermann

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=ZePerBa3QAvoFVSR@debian \
    --to=alx@kernel.org \
    --cc=jsm-csl@polyomino.org.uk \
    --cc=libc-alpha@sourceware.org \
    --cc=linux-man@vger.kernel.org \
    --cc=mwelinder@gmail.com \
    --cc=newbie-02@gmx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).