From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12086 invoked by alias); 9 Jan 2012 20:03:28 -0000 Received: (qmail 12076 invoked by uid 22791); 9 Jan 2012 20:03:27 -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; Mon, 09 Jan 2012 20:03:15 +0000 From: "martyn.j.corden at intel dot com" To: glibc-bugs@sources.redhat.com Subject: [Bug math/13381] rounding problem wih sincosl Date: Mon, 09 Jan 2012 20:03:00 -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: martyn.j.corden at intel dot com X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: aj at suse dot de X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: CC Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 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: 2012-01/txt/msg00071.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=3D13381 martyn.j.corden at intel dot com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |martyn.j.corden at intel | |dot com --- Comment #13 from martyn.j.corden at intel dot com 2012-01-09 20:02:37 U= TC --- Yes, this is likely an issue of slightly different algorithms in the math library. The main purpose of a sincos function is to give results more quickly/efficiently that two separate calls to sin and cos, and that might = be better achieved with a different algorithm. The same issue arose in the math library provided with the Intel compiler, libimf. Following a customer report, a change was made for version 12.1 of the Intel compiler, (in Intel Composer XE 2011 SP1), so that sincosl would return the same results as calls to sinl and cosl. Presumably, similar changes could be made to the GNU libm if this is felt to be an important is= sue, otherwise the sincos documentation should be updated to warn of the potenti= al difference. If you have access to Intel=E2=80=99s libimf, it is also possi= ble to link to it when compiling with gcc, to work around this issue. Martyn Corden (Intel Developer Support) --=20 Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=3Demail ------- You are receiving this mail because: ------- You are on the CC list for the bug.