From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 120356 invoked by alias); 14 Sep 2015 11:20:14 -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 120314 invoked by uid 48); 14 Sep 2015 11:20:09 -0000 From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/67510] x86: Faster code is possible for integer absolute value Date: Mon, 14 Sep 2015 11:20:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 5.2.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: minor X-Bugzilla-Who: rguenth at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: 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: keywords bug_status cf_reconfirmed_on everconfirmed 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: 2015-09/txt/msg01140.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67510 Richard Biener changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |missed-optimization Status|UNCONFIRMED |NEW Last reconfirmed| |2015-09-14 Ever confirmed|0 |1 --- Comment #1 from Richard Biener --- Confirmed. x86 doesn't have integer abs patterns it seems and we end up using expand_abs_nojump()s /* If this machine has expensive jumps, we can do integer absolute value of X as (((signed) x >> (W-1)) ^ x) - ((signed) x >> (W-1)), where W is the width of MODE. */