From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19078 invoked by alias); 5 Jul 2013 14:14:40 -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 19009 invoked by uid 48); 5 Jul 2013 14:14:32 -0000 From: "ysrumyan at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/57796] AVX2 gather vectorization: code bloat and reduction of performance Date: Fri, 05 Jul 2013 14:14:00 -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: 4.9.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ysrumyan at gmail dot com X-Bugzilla-Status: UNCONFIRMED 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: 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: 2013-07/txt/msg00323.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57796 --- Comment #4 from Yuri Rumyantsev --- (In reply to Jakub Jelinek from comment #3) > By tuning I've meant the vectorizer cost model. If the desirability of > gathers vs. no vectorization at all doesn't depend only on the insns in the > loop, but also on how many iterations the loop has, then perhaps we'd need > to runtime version it or something. Jakub, We have runtime versioning but for original bench vectorized version of loop is selected to execute, but if we change lower bound to 0 (as I did) scalar version of loop is run.