From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1132 invoked by alias); 2 May 2014 15:58:02 -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 Received: (qmail 485 invoked by uid 48); 2 May 2014 15:57:58 -0000 From: "law at redhat dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/59429] Missed optimization opportunity in qsort-style comparison functions Date: Fri, 02 May 2014 15:58:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Version: 4.8.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: minor X-Bugzilla-Who: law at redhat dot com X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2014-05/txt/msg00076.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59429 Jeffrey A. Law changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |law at redhat dot com --- Comment #5 from Jeffrey A. Law --- For expression: (a_3(D) > b_4(D) ? 1 : -((int) (a_3(D) != b_4(D)))) we should transform it instead to: (a_3(D) < b_4(D) ? -1 : (int) (a_3(D) != b_4(D))) Ugh. That seems fairly complex for the existing transformations. Though I guess we could match on cond1 ? -1 : -(int) cond2 Where the conditions aren't necessarily related. We'd turn that into cond1'