From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24890 invoked by alias); 26 Apr 2013 15:07:08 -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 24810 invoked by uid 55); 26 Apr 2013 15:07:04 -0000 From: "joseph at codesourcery dot com" To: glibc-bugs@sourceware.org Subject: [Bug math/14412] Removal of sysdeps/x86_64/fpu/s_sincos.S causes regressions Date: Fri, 26 Apr 2013 15:07:00 -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: joseph at codesourcery dot com 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" MIME-Version: 1.0 X-SW-Source: 2013-04/txt/msg00178.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=14412 --- Comment #23 from joseph at codesourcery dot com 2013-04-26 15:07:02 UTC --- It's only a limited subset of transcendental functions for which glibc is trying to be correctly rounding, and only for double for those functions; for most functions the aim is generally errors within "a few" ulps (and ISO C doesn't specify particular accuracy requirements), though correctly rounding would be some sort of ideal. Implementing the proposed TS 18661 bindings to IEEE 754-2008 would be a huge amount of work (and require compiler work as well), but if anyone gets the time for that work then I believe part 4 of the draft TS will reserve names such as crsin for correctly rounding functions (and crsinf128 for correctly rounding sine for _Float128, etc.), without requiring those functions, so it might make sense eventually to provide those names for correctly-rounding functions where available without making them the default versions. So far I'm still working on going through the accumulated libm bugs that don't require such huge amounts of work as DTS 18661 or ISO 24747 implementation - where one reported bug often shows up lots of related bugs not previously in Bugzilla, that also need to be fixed - rather than trying to find time for larger libm projects (and I'm also mostly leaving aside libm bugs in areas where others have shown interest in fixing them, such as performance or errno handling). (The present functions, producing correctly-rounded results only for round-to-nearest, would not of course meet the requirements for functions such as crsin, although it's probably possible to adapt them by just doing a little bit of final arithmetic in the original rounding mode, having done the intermediate computations to produce a higher-precision result in round-to-nearest.) -- 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.