From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Hinsen Subject: Re: Feedback from JRES in Dijon Date: Fri, 06 Dec 2019 13:24:57 +0100 Message-ID: References: <8D474474-AF4C-4B03-9D38-3BB089BEE4EB@lepiller.eu> <87tv6ec048.fsf@ambrevar.xyz> <14A62244-3626-4146-B40E-BC5CED4B78D3@lepiller.eu> <20191206070455.GA28637@PhantoNv4ArchGx.localdomain> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from eggs.gnu.org ([2001:470:142:3::10]:56566) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1idETz-0006xp-WE for guix-devel@gnu.org; Fri, 06 Dec 2019 09:21:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1idETx-0001U8-HU for guix-devel@gnu.org; Fri, 06 Dec 2019 09:21:23 -0500 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]:57489) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1idETx-0001Pq-0m for guix-devel@gnu.org; Fri, 06 Dec 2019 09:21:21 -0500 In-Reply-To: <20191206070455.GA28637@PhantoNv4ArchGx.localdomain> List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: Bengt Richter , zimoun Cc: Guix Devel Hi Bengt, >> [1] https://webcast.in2p3.fr/video/les-enjeux-et-defis-de-la-recherche-reproductible >> https://aramis.resinfo.org/wiki/lib/exe/fetch.php?media=pleniaires:aramis_keynote_enjeux-et-defis-recherche-reproductible_konrad_hinsen.pdf >> > > Is [1] available as a libre video download? No idea. I can answer most questions about the content since I am the speaker, but I was not involved with recording and publishing. > IMO if you can't reproduce bit-identical results, you should find out _exactly_ why. > And if you do get exactly the same result, you should also know exactly why ;-) That's a nice way to put it! > The video touches on IEEE 754 (and I do believe the lecturer > understands these issues, but he says (IIU.fr :) no programming > language gives control over the FPU -- is that true?? I mean, > including on-the-metal x86_64 assembly language?? I wouldn't count that as a programming language, but that is of course debatable. For me, a programming language is a platform-neutral medium that can be run on any type of computer. And yes, you can argue that the subset of x86 assembly that doesn't manipulate hardware other than registers fits that definition, but you have to draw the line somewhere. More interestingly (definitions aren't really interesting), I am of course not certain that there is no programming language that gives access to the full IEEE754 programming model. I am not aware of any, but if there is, I'd like to find out! > BTW, if you are interested in floating point, links from here should be fun: > > --8<---------------cut here---------------start------------->8--- > https://en.wikipedia.org/wiki/William_Kahan > --8<---------------cut here---------------end--------------->8--- Indeed. For those unfamiliar with that name, Kahan designed the 8087 floating-point processor for Intel and was the main driver behind the IEEE 754 standardization effort. Cheers, Konrad.