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: bignum branch Date: Tue, 17 Jul 2018 15:39:02 -0700 Organization: UCLA Computer Science Department Message-ID: <4bc2a6ba-bc73-c4a9-f7a6-20303955bc7f@cs.ucla.edu> References: <87o9fbbw1t.fsf@tromey.com> <86in5jdj49.fsf@gmail.com> <83wotxaiwi.fsf@gnu.org> <86k1pxmvmx.fsf@gmail.com> <83efg4a6ie.fsf@gnu.org> <41221ccf-0c1a-c7e6-2204-e3f9056f7eb5@cs.ucla.edu> <838t6c9wx5.fsf@gnu.org> <53ba128d-7888-e15a-c4a2-1d7a65f51345@cs.ucla.edu> <83wotu7fcj.fsf@gnu.org> <83k1pt7q1e.fsf@gnu.org> <83h8kx7oeu.fsf@gnu.org> <83fu0h7nr6.fsf@gnu.org> <83d0vl7kg2.fsf@gnu.org> 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 1531867035 22663 195.159.176.226 (17 Jul 2018 22:37:15 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 17 Jul 2018 22:37:15 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 Cc: andrewjmoreton@gmail.com, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Jul 18 00:37:11 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 1ffYak-0005n7-Nv for ged-emacs-devel@m.gmane.org; Wed, 18 Jul 2018 00:37:10 +0200 Original-Received: from localhost ([::1]:33706 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ffYcr-0002dE-DL for ged-emacs-devel@m.gmane.org; Tue, 17 Jul 2018 18:39:21 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:47274) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ffYch-0002d7-UD for emacs-devel@gnu.org; Tue, 17 Jul 2018 18:39:12 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ffYch-00044U-27 for emacs-devel@gnu.org; Tue, 17 Jul 2018 18:39:11 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:42800) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ffYcb-00040O-Hi; Tue, 17 Jul 2018 18:39:05 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 426AF16081E; Tue, 17 Jul 2018 15:39:04 -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 Cfq7GAvi1ITY; Tue, 17 Jul 2018 15:39:03 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 5FA9C160825; Tue, 17 Jul 2018 15:39:03 -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 vnZ_c4zJo8b6; Tue, 17 Jul 2018 15:39:03 -0700 (PDT) Original-Received: from [192.168.1.9] (unknown [47.154.30.119]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 0FCF916060E; Tue, 17 Jul 2018 15:39:03 -0700 (PDT) Openpgp: preference=signencrypt Autocrypt: addr=eggert@cs.ucla.edu; prefer-encrypt=mutual; keydata= xsFNBEyAcmQBEADAAyH2xoTu7ppG5D3a8FMZEon74dCvc4+q1XA2J2tBy2pwaTqfhpxxdGA9 Jj50UJ3PD4bSUEgN8tLZ0san47l5XTAFLi2456ciSl5m8sKaHlGdt9XmAAtmXqeZVIYX/UFS 96fDzf4xhEmm/y7LbYEPQdUdxu47xA5KhTYp5bltF3WYDz1Ygd7gx07Auwp7iw7eNvnoDTAl KAl8KYDZzbDNCQGEbpY3efZIvPdeI+FWQN4W+kghy+P6au6PrIIhYraeua7XDdb2LS1en3Ss mE3QjqfRqI/A2ue8JMwsvXe/WK38Ezs6x74iTaqI3AFH6ilAhDqpMnd/msSESNFt76DiO1ZK QMr9amVPknjfPmJISqdhgB1DlEdw34sROf6V8mZw0xfqT6PKE46LcFefzs0kbg4GORf8vjG2 Sf1tk5eU8MBiyN/bZ03bKNjNYMpODDQQwuP84kYLkX2wBxxMAhBxwbDVZudzxDZJ1C2VXujC OJVxq2kljBM9ETYuUGqd75AW2LXrLw6+MuIsHFAYAgRr7+KcwDgBAfwhPBYX34nSSiHlmLC+ KaHLeCLF5ZI2vKm3HEeCTtlOg7xZEONgwzL+fdKo+D6SoC8RRxJKs8a3sVfI4t6CnrQzvJbB n6gxdgCu5i29J1QCYrCYvql2UyFPAK+do99/1jOXT4m2836j1wARAQABzSBQYXVsIEVnZ2Vy dCA8ZWdnZXJ0QGNzLnVjbGEuZWR1PsLBfgQTAQIAKAUCTIByZAIbAwUJEswDAAYLCQgHAwIG FQgCCQoLBBYCAwECH In-Reply-To: <83d0vl7kg2.fsf@gnu.org> 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:227523 Archived-At: Eli Zaretskii wrote: > But that problem will affect all platforms, wouldn't it? Because GMP > can only work with 'long', and I guess we don't want to rely on stuff > like 'prtdiff_t' and 'intmax_t' being no wider than 'long'? We'd need > to convert the other types explicitly. Yes, of course. However, the more of these types are wider than a GMP lim= b, the=20 more problems we'll have. There's another thing about debugging. This stuff is still uncertain. Tha= t is,=20 there are no doubt bugs in the bignum branch in this area, and we don't k= now yet=20 how significant these correctness problems will be. With that in mind, it= would=20 be useful to have avoid-libgmp options with our own GMP replacement that = uses=20 uintmax_t limbs (or 'unsigned int' limbs, for that matter) for debugging=20 purposes, to help us debug the inevitable glitches that will arise due to= =20 libgmp's limbs being wrong for some types. I looked into libgmp, and it appears that all we would need is a 2-line c= hange=20 to mini-gmp.h. This should not be hard to maintain ourselves, with the id= ea of=20 propagating it upstream when we can.