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: Emacs Lisp JIT Compiler Date: Wed, 15 Aug 2018 10:16:55 -0700 Organization: UCLA Computer Science Department Message-ID: References: <87va8ej4o1.fsf@tromey.com> <87mutpiyz6.fsf@tromey.com> <701cd05f423e0c46595a3010f45414d0.squirrel@dancol.org> <520f536b5a603831c9a57a5f6f0978a2.squirrel@dancol.org> <83va8binu8.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 1534354510 26010 195.159.176.226 (15 Aug 2018 17:35:10 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 15 Aug 2018 17:35:10 +0000 (UTC) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 Cc: dancol@dancol.org, tom@tromey.com, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Aug 15 19:35:05 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 1fpzhI-0006cz-IT for ged-emacs-devel@m.gmane.org; Wed, 15 Aug 2018 19:35:04 +0200 Original-Received: from localhost ([::1]:50692 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fpzjP-0004rT-2c for ged-emacs-devel@m.gmane.org; Wed, 15 Aug 2018 13:37:15 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:56999) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fpzim-0004rN-Ky for emacs-devel@gnu.org; Wed, 15 Aug 2018 13:36:37 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fpzil-0001Cu-KQ for emacs-devel@gnu.org; Wed, 15 Aug 2018 13:36:36 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:50694) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fpzif-00019r-T0; Wed, 15 Aug 2018 13:36:30 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 0FD001600CC; Wed, 15 Aug 2018 10:16:57 -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 WZV3AnC2E2-x; Wed, 15 Aug 2018 10:16:56 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 4F452160192; Wed, 15 Aug 2018 10:16:56 -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 k8mSiwPssiOp; Wed, 15 Aug 2018 10:16:56 -0700 (PDT) Original-Received: from [192.168.1.9] (unknown [47.154.30.119]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id E49F41600CC; Wed, 15 Aug 2018 10:16:55 -0700 (PDT) In-Reply-To: <83va8binu8.fsf@gnu.org> Content-Language: en-US X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x 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:228565 Archived-At: Eli Zaretskii wrote: > we should choose our JIT library so that it doesn't > suffer from such issues Yes, of course that would be preferable. However, performance variation is just one factor, and other factors in JIT libraries are just as important, if not more so. We shouldn't have this one factor overriding everything else. Besides, none of the JIT approaches we're talking about are free from the issues Daniel raised: they all have significant performance differences on different platforms. If we're going to reject a JIT approach merely because a 3x performance improvement on one platform isn't equally shared by other platforms, we might as well just be up front about it and say we're going to reject all JIT approaches. (If performance variation is really a problem, we could have Emacs default to running slowly on all platforms, and speed up only when the user asks it to. :-)