From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26972 invoked by alias); 2 May 2008 12:33:10 -0000 Received: (qmail 26686 invoked by alias); 2 May 2008 12:32:22 -0000 Date: Fri, 02 May 2008 12:33:00 -0000 Message-ID: <20080502123222.26685.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/32921] [4.3/4.4 Regression] Revision 126326 causes 12% slowdown In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "dnovillo at google dot com" 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: 2008-05/txt/msg00091.txt.bz2 ------- Comment #50 from dnovillo at google dot com 2008-05-02 12:32 ------- Subject: Re: [4.3/4.4 Regression] Revision 126326 causes 12% slowdown On 05/02/08 08:16, rguenth at gcc dot gnu dot org wrote: > and dropping the final dom pass in favor of another FRE one (DOM has > weaker memory optimization but in addition does some jump threading and > cond expr combining, both of which don't happen a lot after loop > optimizations). Along these lines, I think we would really benefit from doing a thorough study of pass reordering using the techniques in GCC-ICI (GCC Summit 2008) and COLE (CGO 2008). Both have found significant improvements with different optimization pipelines. > Note that teaching DOM about the alias-oracle is very difficult and > unlikely to happen - I'd rather get rid of DOM completely. Agreed. Diego. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32921