From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1247 invoked by alias); 21 Oct 2010 19:26:24 -0000 Received: (qmail 1236 invoked by uid 22791); 21 Oct 2010 19:26:23 -0000 X-SWARE-Spam-Status: No, hits=-2.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,MISSING_MID 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; Thu, 21 Oct 2010 19:26:19 +0000 From: "zimmerma+gcc at loria dot fr" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/46080] [4.4/4.5/4.6 Regression] incorrect precision of sqrtf builtin for x87 arithmetic (-mfpmath=387) X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: zimmerma+gcc at loria dot fr X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.4.6 X-Bugzilla-Changed-Fields: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Date: Thu, 21 Oct 2010 19:26:00 -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: 2010-10/txt/msg01826.txt.bz2 Message-ID: <20101021192600.YgBE0wjDIPhIyGMliFUkVVJyXq8k0aRkGi3qRKonP_E@z> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46080 --- Comment #9 from Paul Zimmermann 2010-10-21 19:26:11 UTC --- (In reply to comment #8) > You really should use hex float to see the diferences. I bet it is just the > final digit of the hex float that is different and only by one. This is > actually ok IIRC. see comment 5. (Moreover the sqrt function must return correct rounding according to IEEE 754, thus even a difference of 1 ulp is *not* ok.) Paul Zimmermann