From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#5754: Bytecomp Arithmetic test failed Date: Sun, 04 Apr 2010 09:25:10 +0300 Message-ID: <83zl1jzqd5.fsf@gnu.org> References: <87ocifjx74.fsf@mail.jurta.org> <87iq88ma6c.fsf@stupidchicken.com> NNTP-Posting-Host: lo.gmane.org X-Trace: dough.gmane.org 1270364172 4252 80.91.229.12 (4 Apr 2010 06:56:12 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sun, 4 Apr 2010 06:56:12 +0000 (UTC) Cc: 5754@debbugs.gnu.org To: Chong Yidong Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sun Apr 04 08:56:07 2010 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1NyJkb-0004fR-W5 for geb-bug-gnu-emacs@m.gmane.org; Sun, 04 Apr 2010 08:56:06 +0200 Original-Received: from localhost ([127.0.0.1]:49136 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NyJkb-0007yg-FX for geb-bug-gnu-emacs@m.gmane.org; Sun, 04 Apr 2010 02:56:05 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NyJkW-0007yR-Ce for bug-gnu-emacs@gnu.org; Sun, 04 Apr 2010 02:56:00 -0400 Original-Received: from [140.186.70.92] (port=43412 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NyJkS-0007wk-Fp for bug-gnu-emacs@gnu.org; Sun, 04 Apr 2010 02:55:59 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1NyJkQ-00056E-T1 for bug-gnu-emacs@gnu.org; Sun, 04 Apr 2010 02:55:56 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:53030) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1NyJkQ-000563-OR for bug-gnu-emacs@gnu.org; Sun, 04 Apr 2010 02:55:54 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.69) (envelope-from ) id 1NyJIU-0003s0-1P; Sun, 04 Apr 2010 02:27:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 04 Apr 2010 06:27:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 5754 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 5754-submit@debbugs.gnu.org id=B5754.127036237514866 (code B ref 5754); Sun, 04 Apr 2010 06:27:02 +0000 Original-Received: (at 5754) by debbugs.gnu.org; 4 Apr 2010 06:26:15 +0000 Original-Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1NyJHi-0003rj-Sy for submit@debbugs.gnu.org; Sun, 04 Apr 2010 02:26:15 -0400 Original-Received: from mtaout22.012.net.il ([80.179.55.172]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1NyJHg-0003re-Sy for 5754@debbugs.gnu.org; Sun, 04 Apr 2010 02:26:13 -0400 Original-Received: from conversion-daemon.a-mtaout22.012.net.il by a-mtaout22.012.net.il (HyperSendmail v2007.08) id <0L0C001009M2FA00@a-mtaout22.012.net.il> for 5754@debbugs.gnu.org; Sun, 04 Apr 2010 09:25:16 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([77.124.92.42]) by a-mtaout22.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0L0C00LMI9TU5SB0@a-mtaout22.012.net.il>; Sun, 04 Apr 2010 09:25:15 +0300 (IDT) In-reply-to: <87iq88ma6c.fsf@stupidchicken.com> X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Sun, 04 Apr 2010 02:27:02 -0400 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:35916 Archived-At: > From: Chong Yidong > Date: Sat, 03 Apr 2010 18:40:59 -0400 > Cc: 5754@debbugs.gnu.org > > The key is that if I compile Emacs with CFLAGS="-g", then > > (funcall > (byte-compile > (list 'lambda nil > (quote (let ((a (expt 2 -1074)) (b 0.125)) (* a 8 b)))))) > > returns 0.0. If I compile Emacs with CFLAGS="-g -O2", then it returns > 5e-324. > > It looks like this may be a compiler bug. I doubt it. I see this in GCC 3.4.x; the chances that two very different versions have the same bug are less than slim, I think. I'd suspect some bug in our code, before considering a GCC bug.