From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14898 invoked by alias); 21 Dec 2012 14:09:08 -0000 Received: (qmail 14410 invoked by uid 48); 21 Dec 2012 14:08:28 -0000 From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/55334] [4.8 Regression] mgrid regression (ipa-cp disables vectorization) Date: Fri, 21 Dec 2012 14:09:00 -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: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenth 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: 4.8.0 X-Bugzilla-Changed-Fields: 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: 2012-12/txt/msg02127.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55334 --- Comment #19 from Richard Biener 2012-12-21 14:08:24 UTC --- Btw, one thing to improve would be the excessive number of aliasing runtime checks the vectorizer currently generates. That would also help himeno. What is missing here is conservative merging of tests (thus making them slightly less precise for the sake of reducing their number). We create different tests for, say, R vs. U(I1, I2, I3) and R vs. U(I1-1,I2, I3). It's of course not that trivial, otherwise somebody would have done it already (see vect_prune_runtime_alias_test_list - we only merge equal range tests and do not try to use a convex hull to cover multiple tests with one).