From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24980 invoked by alias); 11 Feb 2011 00:27:05 -0000 Received: (qmail 24972 invoked by uid 22791); 11 Feb 2011 00:27:04 -0000 X-SWARE-Spam-Status: No, hits=-2.7 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 11 Feb 2011 00:27:00 +0000 From: "jrt at worldlinc dot net" To: gcc-bugs@gcc.gnu.org Subject: [Bug fortran/47692] New: Numeric inaccuracy reported in testing lapack-3.3.0 BLAS module X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: fortran X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: jrt at worldlinc dot net X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Date: Fri, 11 Feb 2011 00:28:00 -0000 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: 2011-02/txt/msg01379.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47692 Summary: Numeric inaccuracy reported in testing lapack-3.3.0 BLAS module Product: gcc Version: 4.6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned@gcc.gnu.org ReportedBy: jrt@worldlinc.net A number of BLAS testing results were not clean. Some results were reported to be suspect and others were reported to be fatal errors. Here's a paste of one such result: ******* FATAL ERROR - COMPUTED RESULT IS LESS THAN HALF ACCURATE ******* EXPECTED RESULT COMPUTED RESULT 1 ( 0.551243 , -0.533049E-01) ( 0.551243 , -0.533049E-01) 2 ( -0.816325E-01, 0.389502 ) ( -0.816325E-01, 0.389502 ) ******* CGEMV FAILED ON CALL NUMBER: 10: CGEMV ('N', 2, 1,( 0.7,-0.9), A, 3, X, 1,( 0.0, 0.0), Y, 1) . I don't know why BLAS routines didn't test cleanly, but it appears that most severe results were in Complex Level I BLAS. There are some REAL and DOUBLE problems too. This is a well-established numeric library that as I recall tested cleanly with gfortran 4.4.5. The results from testing BLAS and Lapack are in two text files that I can make available, though independent verification is of course needed for this.