From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Using the GNU GMP Library for Bignums in Emacs Date: Sun, 22 Apr 2018 10:47:10 -0700 Organization: UCLA Computer Science Department Message-ID: <42cbc5ab-2f02-4aa5-4b19-7b2357f91692@cs.ucla.edu> References: <29f933ac-a6bf-8742-66a7-0a9d6d3e5a88@disroot.org> <83bmecy6fx.fsf@gnu.org> <0d3175d8-d996-651e-b221-71978bde3a65@cs.ucla.edu> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Trace: blaine.gmane.org 1524419160 9462 195.159.176.226 (22 Apr 2018 17:46:00 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sun, 22 Apr 2018 17:46:00 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 To: Helmut Eller , emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Apr 22 19:45:56 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fAJ3j-0002Ll-Pi for ged-emacs-devel@m.gmane.org; Sun, 22 Apr 2018 19:45:55 +0200 Original-Received: from localhost ([::1]:47343 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fAJ5q-00039f-Ai for ged-emacs-devel@m.gmane.org; Sun, 22 Apr 2018 13:48:06 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:42051) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fAJ53-00039A-KO for emacs-devel@gnu.org; Sun, 22 Apr 2018 13:47:18 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fAJ4y-000520-On for emacs-devel@gnu.org; Sun, 22 Apr 2018 13:47:17 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:42704) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fAJ4y-000511-Ij for emacs-devel@gnu.org; Sun, 22 Apr 2018 13:47:12 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id AF10A1616C5; Sun, 22 Apr 2018 10:47:11 -0700 (PDT) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id tbc7h-d8jcDM; Sun, 22 Apr 2018 10:47:11 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 07D821616D5; Sun, 22 Apr 2018 10:47:11 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id CsKfmHmxJ-s3; Sun, 22 Apr 2018 10:47:10 -0700 (PDT) Original-Received: from [192.168.1.9] (unknown [47.154.30.119]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id DC9D21616C5; Sun, 22 Apr 2018 10:47:10 -0700 (PDT) In-Reply-To: Content-Language: en-US X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 131.179.128.68 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:224789 Archived-At: Helmut Eller wrote: > (format "%x" -1) =3D> "3fffffffffffffff". Any program that assumes that behavior is already unportable, since the=20 expression returns "3fffffff" on 32-bit platforms. The usual approach for this is to format negative numbers with a leading = minus=20 sign, so that (format "%x" -1) returns "-1". This is what Emac Lisp shoul= d have=20 been doing anyway as it is more intuitive and more portable. Obviously th= ere=20 will be compatibility concerns here, and we'll need to address them.