From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29591 invoked by alias); 29 Feb 2012 12:34:00 -0000 Received: (qmail 29577 invoked by uid 22791); 29 Feb 2012 12:33:59 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 29 Feb 2012 12:33:46 +0000 From: "marc.glisse at normalesup dot org" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/22200] numeric_limits::is_modulo is inconsistent with gcc Date: Wed, 29 Feb 2012 12:41:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: marc.glisse at normalesup dot org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: CC Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2012-02/txt/msg02791.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22200 Marc Glisse changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |marc.glisse at normalesup | |dot org --- Comment #40 from Marc Glisse 2012-02-29 12:32:10 UTC --- I haven't seen it mentioned in the discussion here, but in C++11, the definition of is_modulo was clarified as: "True if the type is modulo. A type is modulo if, for any operation involving +, -, or * on values of that type whose result would fall outside the range [min(),max()], the value returned differs from the true value by an integer multiple of max() - min() + 1." Do people have objections to switching numeric_limits::is_modulo to false (setting it to true when -fwrapv is used can still be discussed afterwards)?