From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15971 invoked by alias); 1 Mar 2012 21:26:20 -0000 Received: (qmail 15948 invoked by uid 22791); 1 Mar 2012 21:26:19 -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 sourceware.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 01 Mar 2012 21:26:07 +0000 From: "rsa at us dot ibm.com" To: glibc-bugs@sources.redhat.com Subject: [Bug math/887] Math library function "logb" and "nextafter" inconsistent Date: Thu, 01 Mar 2012 21:26:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: math X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: rsa at us dot ibm.com X-Bugzilla-Status: ASSIGNED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: rsa at us dot ibm.com X-Bugzilla-Target-Milestone: 2.16 X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact glibc-bugs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: glibc-bugs-owner@sourceware.org X-SW-Source: 2012-03/txt/msg00027.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=887 --- Comment #18 from Ryan S. Arnold 2012-03-01 21:26:05 UTC --- A bit more investigation reveals the issue: Building logb with -mcpu=power4 or -mcpu=ppc970 results in a negative signed zero. This is due to the power4 and ppc970 versions using fsub. The fcfid insn was introduced after power4 and logb uses that when built for power5 and power6. A negative signed zero is not encountered in these cases. So technically YES, this is still an issue, but it originates in GCC due to insn selection. -- Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.