From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32143 invoked by alias); 1 May 2013 22:25:18 -0000 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 Received: (qmail 32081 invoked by uid 48); 1 May 2013 22:25:15 -0000 From: "bugdal at aerifal dot cx" To: glibc-bugs@sourceware.org Subject: [Bug math/14412] Removal of sysdeps/x86_64/fpu/s_sincos.S causes regressions Date: Wed, 01 May 2013 22:25:00 -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: enhancement X-Bugzilla-Who: bugdal at aerifal dot cx X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: 2.18 X-Bugzilla-Changed-Fields: 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 X-SW-Source: 2013-05/txt/msg00006.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=3D14412 --- Comment #47 from Rich Felker 2013-05-01 22:2= 5:14 UTC --- Another citation, from the C99 Rationale (http://www.open-std.org/jtc1/sc22/wg14/www/C99RationaleV5.10.pdf), support= ing the option to give wrong results for trig functions: Page 27, lines 9-13: "Some math functions such as those that do argument reduction modulo an approximation of =CF=80 have good accuracy for small arguments, but poor ac= curacy for large arguments. It is not unusual for an implementation of the trigonometric functions to have zero bits correct in the computed result for large arguments. For cases like this, an implementation might break the dom= ain of the function into disjoint regions and specify the accuracy in each regi= on." Note that an implementation should still document the accuracy, and in the = case of wrong argument reduction, the error could theoretically be as large as 2**1074 ULPs for some inputs of sin/cos (if the correct result were denormal but the function returned 1.0 or -1.0) and much worse (even possibly infini= te) for tan. --=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. >>From glibc-bugs-return-18560-listarch-glibc-bugs=sources.redhat.com@sourceware.org Wed May 01 22:26:33 2013 Return-Path: Delivered-To: listarch-glibc-bugs@sources.redhat.com Received: (qmail 327 invoked by alias); 1 May 2013 22:26:33 -0000 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 Delivered-To: mailing list glibc-bugs@sourceware.org Received: (qmail 32762 invoked by uid 48); 1 May 2013 22:26:30 -0000 From: "jsm28 at gcc dot gnu.org" To: glibc-bugs@sourceware.org Subject: [Bug math/15427] New: Spurious underflow from lgammaf Date: Wed, 01 May 2013 22:26:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new 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: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 X-SW-Source: 2013-05/txt/msg00007.txt.bz2 Content-length: 639 http://sourceware.org/bugzilla/show_bug.cgi?id=15427 Bug #: 15427 Summary: Spurious underflow from lgammaf Product: glibc Version: 2.17 Status: NEW Severity: normal Priority: P2 Component: math AssignedTo: unassigned@sourceware.org ReportedBy: jsm28@gcc.gnu.org Classification: Unclassified On x86_64, lgammaf (-0x1p-64) raises a spurious underflow exception. -- 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.