Rocksolid Light

Welcome to novaBBS (click a section below)

mail  files  register  newsreader  groups  login

Message-ID:  

Profanity is the one language all programmers know best.


devel / comp.arch / Re: The value of floating-point exceptions?

SubjectAuthor
* The value of floating-point exceptions?Marcus
+* Re: The value of floating-point exceptions?Marcus
|`* Re: The value of floating-point exceptions?Stephen Fuld
| +- Re: The value of floating-point exceptions?Marcus
| `* Re: The value of floating-point exceptions?luke.l...@gmail.com
|  `- Re: The value of floating-point exceptions?BGB
+* Re: The value of floating-point exceptions?John Dallman
|+* Re: The value of floating-point exceptions?Marcus
||`* Re: The value of floating-point exceptions?John Dallman
|| +- Re: The value of floating-point exceptions?MitchAlsup
|| `* Re: The value of floating-point exceptions?Quadibloc
||  `* Re: The value of floating-point exceptions?MitchAlsup
||   +* Re: The value of floating-point exceptions?Marcus
||   |+* Re: The value of floating-point exceptions?Ivan Godard
||   ||`* Re: The value of floating-point exceptions?Quadibloc
||   || +* Re: The value of floating-point exceptions?Ivan Godard
||   || |+* Re: The value of floating-point exceptions?Anton Ertl
||   || ||`* Re: The value of floating-point exceptions?MitchAlsup
||   || || `- Re: The value of floating-point exceptions?Quadibloc
||   || |`- Re: The value of floating-point exceptions?Terje Mathisen
||   || `* Re: The value of floating-point exceptions?MitchAlsup
||   ||  +* Re: The value of floating-point exceptions?Quadibloc
||   ||  |+* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||+- Re: The value of floating-point exceptions?BGB
||   ||  ||`* Re: The value of floating-point exceptions?Terje Mathisen
||   ||  || `* Re: The value of floating-point exceptions?BGB
||   ||  ||  `* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||   +* Re: The value of floating-point exceptions?Ivan Godard
||   ||  ||   |+* Re: The value of floating-point exceptions?BGB
||   ||  ||   ||`* Re: The value of floating-point exceptions?Terje Mathisen
||   ||  ||   || `- Re: The value of floating-point exceptions?BGB
||   ||  ||   |+* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||   ||`* Re: The value of floating-point exceptions?Marcus
||   ||  ||   || `- Re: The value of floating-point exceptions?BGB
||   ||  ||   |`* Re: The value of floating-point exceptions?EricP
||   ||  ||   | `* Re: The value of floating-point exceptions?Ivan Godard
||   ||  ||   |  `* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||   |   +* Re: Configurable rounding modes (was The value of floating-pointMarcus
||   ||  ||   |   |+- Re: Configurable rounding modes (was The value of floating-pointTerje Mathisen
||   ||  ||   |   |`* Re: Configurable rounding modes (was The value of floating-point exceptions?)MitchAlsup
||   ||  ||   |   | +- Re: Configurable rounding modes (was The value of floating-pointStephen Fuld
||   ||  ||   |   | `- Re: Configurable rounding modes (was The value of floating-pointMarcus
||   ||  ||   |   `* Re: The value of floating-point exceptions?EricP
||   ||  ||   |    `* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||   |     `- Re: The value of floating-point exceptions?Quadibloc
||   ||  ||   +* Re: The value of floating-point exceptions?Quadibloc
||   ||  ||   |`* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||   | `- Re: The value of floating-point exceptions?Quadibloc
||   ||  ||   `* Re: The value of floating-point exceptions?Marcus
||   ||  ||    +* Re: The value of floating-point exceptions?Thomas Koenig
||   ||  ||    |`* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||    | `- Re: The value of floating-point exceptions?Thomas Koenig
||   ||  ||    +* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||    |+* Re: The value of floating-point exceptions?Ivan Godard
||   ||  ||    ||`- Re: The value of floating-point exceptions?BGB
||   ||  ||    |+* Re: The value of floating-point exceptions?Quadibloc
||   ||  ||    ||`* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||    || +* Re: The value of floating-point exceptions?Ivan Godard
||   ||  ||    || |`* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||    || | `* Re: The value of floating-point exceptions?Ivan Godard
||   ||  ||    || |  +* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||    || |  |`- Re: The value of floating-point exceptions?Ivan Godard
||   ||  ||    || |  `* Re: The value of floating-point exceptions?Marcus
||   ||  ||    || |   +- Re: The value of floating-point exceptions?Quadibloc
||   ||  ||    || |   +* Re: The value of floating-point exceptions?Anton Ertl
||   ||  ||    || |   |`* Re: The value of floating-point exceptions?Michael S
||   ||  ||    || |   | `* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||    || |   |  `- Re: The value of floating-point exceptions?Terje Mathisen
||   ||  ||    || |   `* Re: The value of floating-point exceptions?Quadibloc
||   ||  ||    || |    +- Re: The value of floating-point exceptions?Quadibloc
||   ||  ||    || |    `* Re: The value of floating-point exceptions?Marcus
||   ||  ||    || |     `* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||    || |      `* Re: The value of floating-point exceptions?Marcus
||   ||  ||    || |       `- Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||    || `- Re: Configurable rounding modes (was The value of floating-pointMarcus
||   ||  ||    |`* Re: Configurable rounding modes (was The value of floating-pointMarcus
||   ||  ||    | +* Re: Configurable rounding modes (was The value of floating-point exceptions?)MitchAlsup
||   ||  ||    | |`* Re: Configurable rounding modes (was The value of floating-pointIvan Godard
||   ||  ||    | | +* Re: Configurable rounding modes (was The value of floating-pointBGB
||   ||  ||    | | |`* Re: Configurable rounding modes (was The value of floating-pointMarcus
||   ||  ||    | | | `- Re: Configurable rounding modes (was The value of floating-pointBGB
||   ||  ||    | | +* Re: Configurable rounding modes (was The value of floating-point exceptions?)Quadibloc
||   ||  ||    | | |+- Re: Configurable rounding modes (was The value of floating-point exceptions?)Quadibloc
||   ||  ||    | | |`* Re: Configurable rounding modes (was The value of floating-pointIvan Godard
||   ||  ||    | | | `- Re: Configurable rounding modes (was The value of floating-point exceptions?)Quadibloc
||   ||  ||    | | `* Re: Configurable rounding modes (was The value of floating-point exceptions?)MitchAlsup
||   ||  ||    | |  `* Re: Configurable rounding modes (was The value of floating-pointIvan Godard
||   ||  ||    | |   `* Re: Configurable rounding modes (was The value of floating-point exceptions?)Quadibloc
||   ||  ||    | |    `* Re: Configurable rounding modes (was The value of floating-point exceptions?)Quadibloc
||   ||  ||    | |     +- Re: Configurable rounding modes (was The value of floating-point exceptions?)Quadibloc
||   ||  ||    | |     `- Re: Configurable rounding modes (was The value of floating-point exceptions?)Quadibloc
||   ||  ||    | `* Re: Configurable rounding modes (was The value of floating-pointBGB
||   ||  ||    |  `* Re: Configurable rounding modes (was The value of floating-point exceptions?)MitchAlsup
||   ||  ||    |   `- Re: Configurable rounding modes (was The value of floating-pointBGB
||   ||  ||    `* Re: The value of floating-point exceptions?antispam
||   ||  ||     +- Re: The value of floating-point exceptions?BGB
||   ||  ||     +* Re: The value of floating-point exceptions?Terje Mathisen
||   ||  ||     |+- Re: The value of floating-point exceptions?BGB
||   ||  ||     |`* Re: The value of floating-point exceptions?antispam
||   ||  ||     | `* Re: The value of floating-point exceptions?Quadibloc
||   ||  ||     |  +* Re: The value of floating-point exceptions?antispam
||   ||  ||     |  `* Re: The value of floating-point exceptions?MitchAlsup
||   ||  ||     `- Re: The value of floating-point exceptions?John Dallman
||   ||  |`* Re: The value of floating-point exceptions?John Dallman
||   ||  +* Re: The value of floating-point exceptions?Quadibloc
||   ||  `* Re: The value of floating-point exceptions?Thomas Koenig
||   |`* Re: The value of floating-point exceptions?Quadibloc
||   `- Re: The value of floating-point exceptions?Quadibloc
|`* Re: The value of floating-point exceptions?Marcus
+- Re: The value of floating-point exceptions?Terje Mathisen
+* Re: The value of floating-point exceptions?Ivan Godard
+- Re: The value of floating-point exceptions?BGB
+* Re: The value of floating-point exceptions?EricP
+* Re: The value of floating-point exceptions?Anton Ertl
+* Re: The value of floating-point exceptions?MitchAlsup
`- Re: The value of floating-point exceptions?antispam

Pages:12345678910
Re: The value of floating-point exceptions?

<d38a65f3-2d47-4204-b6e2-3010d4677580n@googlegroups.com>

 copy mid

https://www.novabbs.com/devel/article-flat.php?id=20390&group=comp.arch#20390

 copy link   Newsgroups: comp.arch
X-Received: by 2002:a37:a554:: with SMTP id o81mr9215019qke.231.1631302011654;
Fri, 10 Sep 2021 12:26:51 -0700 (PDT)
X-Received: by 2002:a05:6830:238a:: with SMTP id l10mr6091623ots.333.1631302011462;
Fri, 10 Sep 2021 12:26:51 -0700 (PDT)
Path: i2pn2.org!i2pn.org!weretis.net!feeder6.news.weretis.net!news.misty.com!border2.nntp.dca1.giganews.com!nntp.giganews.com!news-out.google.com!nntp.google.com!postnews.google.com!google-groups.googlegroups.com!not-for-mail
Newsgroups: comp.arch
Date: Fri, 10 Sep 2021 12:26:51 -0700 (PDT)
In-Reply-To: <shg7gp$1fe6$1@gioia.aioe.org>
Injection-Info: google-groups.googlegroups.com; posting-host=2600:1700:291:29f0:5027:7e9b:eaf7:6c1;
posting-account=H_G_JQkAAADS6onOMb-dqvUozKse7mcM
NNTP-Posting-Host: 2600:1700:291:29f0:5027:7e9b:eaf7:6c1
References: <sd9a9h$ro6$1@dont-email.me> <sde6m7$kr1$1@dont-email.me>
<sde74m$nio$1@dont-email.me> <7cf5713e-f138-488b-9ccf-d85df84c50can@googlegroups.com>
<e7e0b9a2-7990-4ec8-9c40-a6e9a07bd306n@googlegroups.com> <sdf4t3$6cl$2@newsreader4.netcologne.de>
<c0917435-65c8-45f1-b745-5fd7ff4f58c0n@googlegroups.com> <548e3590-e939-40b7-8f78-3040d59358f7n@googlegroups.com>
<98ee6cd3-1a1e-44a6-848b-20a8d81a6adfn@googlegroups.com> <10a5151f-d8b9-4ff3-a22c-85b0b92fb5f9n@googlegroups.com>
<d5e11715-3204-4544-9e88-9e17085601fan@googlegroups.com> <32d73646-b68a-4da1-917a-45d0cb02f26cn@googlegroups.com>
<dce18e70-5186-43ec-b56f-f67a0791548bn@googlegroups.com> <09524196-320e-484d-9454-68b3e098915bn@googlegroups.com>
<sh9khf$1p9g$1@gioia.aioe.org> <d9864d47-e3bf-4e89-af4f-88876c1363f1n@googlegroups.com>
<403cfd0e-e225-4658-ba63-ba4cd3396b77n@googlegroups.com> <shfd8d$1uuo$1@gioia.aioe.org>
<55bc09b5-cd5a-420a-a250-6ad5a75ba9e4n@googlegroups.com> <shg7gp$1fe6$1@gioia.aioe.org>
User-Agent: G2/1.0
MIME-Version: 1.0
Message-ID: <d38a65f3-2d47-4204-b6e2-3010d4677580n@googlegroups.com>
Subject: Re: The value of floating-point exceptions?
From: MitchAl...@aol.com (MitchAlsup)
Injection-Date: Fri, 10 Sep 2021 19:26:51 +0000
Content-Type: text/plain; charset="UTF-8"
Lines: 54
 by: MitchAlsup - Fri, 10 Sep 2021 19:26 UTC

On Friday, September 10, 2021 at 1:18:04 PM UTC-5, Terje Mathisen wrote:
> MitchAlsup wrote:
> > On Friday, September 10, 2021 at 5:49:51 AM UTC-5, Terje Mathisen wrote:
> >> MitchAlsup wrote:
> >>> On Wednesday, September 8, 2021 at 9:47:56 PM UTC-5, Quadibloc wrote:
> >>>> On Wednesday, September 8, 2021 at 12:17:22 AM UTC-6, Terje Mathisen wrote:
> >>>>> We are rapidly running out of room even in double, so we are getting hw
> >>>>> support both for quad (1:15:112) and double-double (via
> >>>>> AugmentedAddition/AugmentedMultiplication), the latter are useful
> >>>>> building blocks for extended/arbitrary precision as long as the fixed
> >>>>> exponent range doesn't become a problem.
> >>>> I finally looked up quad-double and double-double.
> >>>>
> >>>> While I knew that with special instructions, floating-point formats that
> >>>> allowed unnormalized numbers could be used to perform addition,
> >>>> subtraction, and multiplication in extended precision (and division
> >>>> therefore by Newton-Raphson or Goldschmidt), I didn't think it was
> >>>> even *possible* to use ordinary floating-point instructions which didn't
> >>>> provide additional information to do floating-point at higher precision
> >>>> (except through very slow methods involving using floating-point
> >>>> instructions to do arithmetic at half their precision).
> >>> <
> >>> There is a whole subtopic of exact FP arithmetics, that use several FP
> >>> instructions in a row to perform FP arithmetic without error. Without error
> >>> means:: all of the bits that didn't make it into the first result got into the
> >>> second result.
> >>> <
> >>> The odd thing about IEEE 754 here is that 754 mandates the inexact bit
> >>> gets set on any of these sequences of instructions. My 66000 accesses
> >>> this functionality through the CARRY instruction, and when so used, does
> >>> not set the inexact bit!
> >> The Augmented* pair operations really should not set inexact unless you
> >> get into borderline operations due to exponent range limits.
> >>
> >> I don't remember if this got in as a requirement or just a
> >> recommendation, i.e. there might be implementations actually using
> >> Kahan-style adds internally which do result in inexact on pretty much
> >> all operations.
> > <
> > Getting the inexact bit correct did not get in as either (require or recommend).
> Ouch, sorry!
>
> I'll write this up on the 754 mailing list so that it gets noted for the
> next iteration.
<
Expect a bunch of push back because most current 754-implementations
have to read the current inexactness, do the work, then write the inexactness
back to its holding point.
<
> Terje
>
>
> --
> - <Terje.Mathisen at tmsw.no>
> "almost all programming can be viewed as an exercise in caching"

Pages:12345678910
server_pubkey.txt

rocksolid light 0.9.7
clearnet tor