From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30049 invoked by alias); 15 Jun 2007 21:23:53 -0000 Received: (qmail 29821 invoked by uid 48); 15 Jun 2007 21:23:43 -0000 Date: Fri, 15 Jun 2007 21:23:00 -0000 Message-ID: <20070615212343.29820.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug target/32180] Paranoia UCB GSL TestFloat libm tests fail - accuracy of recent gcc math poor In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "rob1weld at aol dot com" 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: 2007-06/txt/msg01237.txt.bz2 ------- Comment #20 from rob1weld at aol dot com 2007-06-15 21:23 ------- Created an attachment (id=13709) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13709&action=view) Specific example where libm, libcrlibm, and mpfr differ Here is a specific example of three different math libraries providing three different answers to the same question. The number does not use very many decimal places and thus __could__ come up in common use. It is not really how likely the number would be used that is important but what the result of using the answer would be. If your life is important don't be it on this number. This is just one number. How many more could there be, how will you prove you are correct and deduce the actual correct answer in those instances. This is what you must answer. This is why we need a fast, simple, library that is accurate and comes with "proof". -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32180