From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19656 invoked by alias); 22 Feb 2012 22:22:42 -0000 Received: (qmail 19648 invoked by uid 22791); 22 Feb 2012 22:22:41 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,TW_JS X-Spam-Check-By: sourceware.org Received: from localhost (HELO sourceware.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 22 Feb 2012 22:22:29 +0000 From: "jsm28 at gcc dot gnu.org" To: glibc-bugs@sources.redhat.com Subject: [Bug math/2154] accuracy of cacoshl is bad. Date: Wed, 22 Feb 2012 22:22:00 -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: jsm28 at gcc dot gnu.org X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: drepper.fsp at gmail dot com X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Status Resolution 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: 2012-02/txt/msg00385.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=2154 Joseph Myers changed: What |Removed |Added ---------------------------------------------------------------------------- Status|SUSPENDED |RESOLVED Resolution| |INVALID --- Comment #2 from Joseph Myers 2012-02-22 22:22:26 UTC --- The tests given in this bug take the double constants 0.3 and 0.4 and convert them to long double. The results of cacoshl appear to be within a few ULPs of what is expected for those particular long double values, whereas the expectations given in this testcase are the results for infinite-precision constants 0.3 and 0.4 (as opposed to those for values rounded to 53 bits then extended to 64 bits, or rounded directly to 64 bits) - and when your inputs differ by 11 bits from what they were intended to be, 770 ULPs is hardly an unexpected error. So this is not a correct test and there is no sign of undue inaccuracy here (I don't think it's yet expected for complex functions to be last-bit-accurate correctly rounded). -- 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.