From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26615 invoked by alias); 4 Mar 2011 08:32:01 -0000 Received: (qmail 28730 invoked by uid 22791); 3 Mar 2011 18:12:14 -0000 X-SWARE-Spam-Status: No, hits=-0.8 required=5.0 tests=BAYES_40,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: sourceware.org MIME-Version: 1.0 Date: Fri, 04 Mar 2011 08:32:00 -0000 Message-ID: Subject: Floating-point exceptions in the GSL From: Thanh Vo To: gsl-discuss@sourceware.org, bug-gsl@gnu.org Cc: "Earl T. Barr" , Zhendong Su , Brian Gough Content-Type: text/plain; charset=UTF-8 Mailing-List: contact gsl-discuss-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gsl-discuss-owner@sourceware.org X-SW-Source: 2011-q1/txt/msg00007.txt.bz2 Hi, My name's Thanh Vo. My research group is developing a tool to detect floating point exceptions in numerical code. On Aug 11th 2010, we contacted the list to report exception triggering inputs we had found in the GSL. Brian Gough confirmed the exceptions were valid warnings. We have continued our work since then. In this email, we report more, potentially problematic exception-triggering inputs. For each exception, we describe the name of function, the type of exception thrown, the inputs that trigger the exception, and the source line that throws the exception. 1. gsl_sf_bessel_Inu_scaled_asymp_unif_e Invalid: nu = 0.000000e+00 and x = 0.000000e+00 Location: line 359 at bessel.c 2. fg_asymp Divide ByZero: x = 0.000000e+00 Location: line 228 at sinint.c 3. gsl_sf_legendre_P3 Overflow: x = -5.996154e+153 Location: line 95 at legendre_poly.c 4. gsl_sf_gammastar Underflow: x = 8.988466e+307 Location: line 1342 at gamma.c You can see the full list of potential bugs at barr.softwareprocess.es If anyone could confirm whether any of these exceptions are useful warnings or actual bugs, we would appreciate it. We are finishing the tool and will release it as open source after publishing the results. Looking forward to hearing from you, Best regards, Thanh Vo.