From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4148 invoked by alias); 28 Jan 2013 07:30:26 -0000 Received: (qmail 3978 invoked by uid 48); 28 Jan 2013 07:30:06 -0000 From: "glisse at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/56125] [4.7/4.8 Regression] -O2 -ffast-math generates bad code when dividing a double by the square of another double. Date: Mon, 28 Jan 2013 07:30:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: glisse at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Summary Message-ID: 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 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: 2013-01/txt/msg02534.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56125 Marc Glisse changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|-O2 -ffast-math generates |[4.7/4.8 Regression] -O2 |bad code when dividing a |-ffast-math generates bad |double by the square of |code when dividing a double |another double. |by the square of another | |double. --- Comment #2 from Marc Glisse 2013-01-28 07:30:05 UTC --- 4.6 generated a very suboptimal call to the libm pow function, but it didn't have the completely wrong result.