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: Making 'eq' == 'eql' in bignum branch Date: Tue, 31 Jul 2018 15:44:24 -0700 Organization: UCLA Computer Science Department Message-ID: <77d5f8b0-2277-b28e-8565-d3e00c411795@cs.ucla.edu> References: <29f933ac-a6bf-8742-66a7-0a9d6d3e5a88@disroot.org> <49d8ba62-c9a5-9203-d882-8e900b441ff3@cs.ucla.edu> <8e0320d9-e0d0-2b57-57cc-2df4399f133c@cs.ucla.edu> <87lgaio7xd.fsf@tromey.com> <877em1cb0i.fsf@tromey.com> <765767b2-d2e5-a9a6-f724-d58ecf4847bb@cs.ucla.edu> <76081b5d-8c10-0a37-2c97-d4864c0faa80@cs.ucla.edu> <09153aed-361d-4f82-d9ac-b502314769ae@cs.ucla.edu> <83600yt8ih.fsf@gnu.org> <83h8kgpnir.fsf@gnu.org> <7dd71d44-69bc-3adf-576b-8b9e31184a24@cs.ucla.edu> <83d0v4p1si.fsf@gnu.org> <827beb76-3adf-f2f9-33b1-1baee55680cd@cs.ucla.edu> <83wotbo04h.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: 7bit X-Trace: blaine.gmane.org 1533076958 13055 195.159.176.226 (31 Jul 2018 22:42:38 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Tue, 31 Jul 2018 22:42:38 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Aug 01 00:42:34 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 1fkdLd-0003Gg-8R for ged-emacs-devel@m.gmane.org; Wed, 01 Aug 2018 00:42:33 +0200 Original-Received: from localhost ([::1]:60888 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fkdNi-0006oC-BA for ged-emacs-devel@m.gmane.org; Tue, 31 Jul 2018 18:44:42 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:45907) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fkdNZ-0006o7-74 for emacs-devel@gnu.org; Tue, 31 Jul 2018 18:44:34 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fkdNY-0003cK-Av for emacs-devel@gnu.org; Tue, 31 Jul 2018 18:44:33 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:39986) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fkdNT-0003bf-Ly; Tue, 31 Jul 2018 18:44:27 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 6D330160654; Tue, 31 Jul 2018 15:44:25 -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 83kNunQcywPn; Tue, 31 Jul 2018 15:44:24 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 981B2161105; Tue, 31 Jul 2018 15:44:24 -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 TIebmTa6672R; Tue, 31 Jul 2018 15:44:24 -0700 (PDT) Original-Received: from Penguin.CS.UCLA.EDU (Penguin.CS.UCLA.EDU [131.179.64.200]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 7C921160654; Tue, 31 Jul 2018 15:44:24 -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: <83wotbo04h.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:228067 Archived-At: On 07/31/2018 09:12 AM, Eli Zaretskii wrote: > I take it we agree that if someone writes a Lisp program which does FP > calculations, their chance of having a lot of such values would be > quite low, yes? So we should put such use cases aside. Nobody should want to write such a program since Emacs is not intended for and does not perform well with heavy-duty FP calculations. So I agree that we shouldn't worry about such programs; we should focus on "real-world Emacs", so to speak. > One way of estimating what happens in the majority of uses is to find > Emacs APIs other than numerical calculations that can return floats, > and try to analyze what kind of floats will be the result. Like > file-system-info and file-attributes, for example. These should be fine on a 64-bit platform. file-system-info invariably yields floating-point numbers with the bottom three bits zero, due to how modern file systems are built (their sizes are multiples of powers of two). file-attributes returns an exact value unless your file is larger than 2**61 bytes (2 EiB), and once we get to the rare files larger than that we should be using bignums anyway. (The same could be said for file-system-info, of course.) > How faster, in absolute numbers and in percents, will your build > finish with the proposed changes? I won't know unless I take the time to code it up.