From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Lisp reader syntax and bootstrap Date: Sat, 15 Jul 2023 08:22:20 -0700 Organization: UCLA Computer Science Department Message-ID: References: <83cz16k2kx.fsf@gnu.org> <833522jwvr.fsf@gnu.org> <87wmzdjk6l.fsf@yahoo.com> <219844d2-ca07-30f4-4e2c-1b1df76d0fa5@cs.ucla.edu> <83fs60hnj2.fsf@gnu.org> <83cz14guz3.fsf@gnu.org> <83pm52dbzh.fsf@gnu.org> <87y1jqwhhs.fsf@epfl.ch> <835y6uct1j.fsf@gnu.org> <878rbpe7a3.fsf@yahoo.com> <87y1jka126.fsf@yahoo.com> <5a110245-9b1c-be43-ca6e-2d37d3cac077@cs.ucla.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="36097"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Cc: luangruo@yahoo.com, ulm@gentoo.org, eliz@gnu.org, contovob@tcd.ie, emacs-devel@gnu.org To: rms@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Jul 15 17:23:38 2023 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qKh7R-0009AJ-RK for ged-emacs-devel@m.gmane-mx.org; Sat, 15 Jul 2023 17:23:38 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qKh6M-0007Vu-Ha; Sat, 15 Jul 2023 11:22:30 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qKh6J-0007UR-JQ for emacs-devel@gnu.org; Sat, 15 Jul 2023 11:22:27 -0400 Original-Received: from mail.cs.ucla.edu ([131.179.128.66]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qKh6H-0006n6-AY; Sat, 15 Jul 2023 11:22:27 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by mail.cs.ucla.edu (Postfix) with ESMTP id 8C4283C011BD4; Sat, 15 Jul 2023 08:22:22 -0700 (PDT) Original-Received: from mail.cs.ucla.edu ([127.0.0.1]) by localhost (mail.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id P2x_2XwZu1OC; Sat, 15 Jul 2023 08:22:22 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by mail.cs.ucla.edu (Postfix) with ESMTP id 343B13C011BD9; Sat, 15 Jul 2023 08:22:22 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.cs.ucla.edu 343B13C011BD9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cs.ucla.edu; s=9D0B346E-2AEB-11ED-9476-E14B719DCE6C; t=1689434542; bh=5iaVTzdOifihUV5G9FvtEOllLbwHpWOQ+lOfSrJzNv4=; h=Message-ID:Date:MIME-Version:To:From; b=K9QveQfps3L2xWraJBB0t6MnpDq9IuoTwa0o+fsFl5xBUbl0nGU92hQYKMB8mr6dE eU0HrtkcszJMGpyGOgEFXZhzrj1J/XSWZ5l6go9VW9LQaF3LXfYuzDrnWNeXwlhdza k74DSjtikI7Mrx15avB+qmq00kHegF8huhIW91J3Aw1P1+xbiuF5Ulk9+pKZTrpoW3 H18oXP2P6P30BmVJvxCpUwKkyv5p8XKEAkm3s3QdDRunBEh26FRF+/TEwZjnaJ2A9S JrqI/6I+Fw78/k9NRSCdz4GMBaXxMZbkBlnyLnngiT8nOoSa50Yk7rJh/ohWuhOUrU +CgtUdtR03lgw== X-Virus-Scanned: amavisd-new at mail.cs.ucla.edu Original-Received: from mail.cs.ucla.edu ([127.0.0.1]) by localhost (mail.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 3keCEcE-QTC8; Sat, 15 Jul 2023 08:22:22 -0700 (PDT) Original-Received: from [192.168.1.9] (cpe-172-91-119-151.socal.res.rr.com [172.91.119.151]) by mail.cs.ucla.edu (Postfix) with ESMTPSA id 003AF3C011BD4; Sat, 15 Jul 2023 08:22:21 -0700 (PDT) Content-Language: en-US In-Reply-To: Received-SPF: pass client-ip=131.179.128.66; envelope-from=eggert@cs.ucla.edu; helo=mail.cs.ucla.edu X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, NICE_REPLY_A=-0.091, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:307889 Archived-At: On 2023-07-14 19:10, Richard Stallman wrote: > That's a bit of a kludge -- using those values might be wrong for > some purposes... Yes, though there are similar problems even for finite numbers, since they also behave differently on the VAX, sometimes significantly. E.g., VAX subtraction can underflow to zero via catastrophic cancellation, whereas IEEE subtraction cannot. Though my change is indeed a hack, it is an improvement in that Emacs can now start up and load 'calculator' whereas formerly it could not. I "tested" this by manually setting IEEE_FLOATING_POINT to zero on x86-64, and compiling and running the result. Of course this is not the same as a real VAX. > > This patch shouldn't change behavior (or even the executable code) on > > today's platforms. It's purely for computer museums. > > If that's true, maybe your solution is fine. I surveyed the net and it appears to be true. The only Emacs platform that still insists on non-IEEE floating point is NetBSD/vax, and nowadays that platform seems to be run only for computer-museum-like purposes. These uses are rare even by computer-museum standards, as most hobbyist historians that simulate VAXes seem to prefer VMS to NetBSD, I expect partly because VMS "feels" older (it differs more from GNU :-). And VMS-using hobbyists can't run current Emacs, as Emacs 23 dropped VMS support. PS. Are you aware of the licensing dispute over the emulator that hobbyists typically use to run VAX code? This emulator, SIMH, is based on software that dates back to the 1960s, so in some sense it's even older than Emacs. The dispute involves a license clause introduced a year ago that I've not seen before, and it's not clear to me that SIMH is free software any more. However, this change has been disputed and SIMH has forked off a new project Open SIMH that does not have the controversial clause. For details, please see: https://groups.io/g/simh/topic/91528716#1659 The disputed licensing clause is at the end of this change: https://github.com/simh/simh/commit/ce2adce632e1a22e6d76d4bf726d6b863373c550