From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20263 invoked by alias); 12 Apr 2011 14:54:55 -0000 Received: (qmail 20255 invoked by uid 22791); 12 Apr 2011 14:54:54 -0000 X-SWARE-Spam-Status: No, hits=-2.3 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW X-Spam-Check-By: sourceware.org Received: from mail-wy0-f175.google.com (HELO mail-wy0-f175.google.com) (74.125.82.175) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 12 Apr 2011 14:54:45 +0000 Received: by wye20 with SMTP id 20so6817313wye.20 for ; Tue, 12 Apr 2011 07:54:43 -0700 (PDT) MIME-Version: 1.0 Received: by 10.227.37.197 with SMTP id y5mr6764782wbd.4.1302620083765; Tue, 12 Apr 2011 07:54:43 -0700 (PDT) Received: by 10.227.0.140 with HTTP; Tue, 12 Apr 2011 07:54:43 -0700 (PDT) In-Reply-To: <20110412145143.GH23480@codesourcery.com> References: <20110412141626.GF23480@codesourcery.com> <20110412143205.GG23480@codesourcery.com> <20110412145143.GH23480@codesourcery.com> Date: Tue, 12 Apr 2011 14:54:00 -0000 Message-ID: Subject: Re: [PATCH] add statistics counting to postreload, copy-rename, and math-opts From: Richard Guenther To: Nathan Froyd Cc: gcc-patches@gcc.gnu.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org X-SW-Source: 2011-04/txt/msg00896.txt.bz2 On Tue, Apr 12, 2011 at 4:51 PM, Nathan Froyd wr= ote: > On Tue, Apr 12, 2011 at 04:37:42PM +0200, Richard Guenther wrote: >> On Tue, Apr 12, 2011 at 4:32 PM, Nathan Froyd = wrote: >> > Thanks. =A0I may go twiddle that patch to do something similar to mine= and >> > submit that. =A0Do you use your patch for checking that the same set of >> > optimizations get performed, then? =A0I'm interested in using the >> > statistics for identifying passes that don't buy us much across a wide >> > variety of codebases. =A0(Suggestions for suitable ones welcome!) >> >> Yes, I used it exactly for that. =A0And also to verify that passes don't >> do anything if replicated (well, for those that shouldn't at least). >> >> Don't expect any low-hanging fruit though ;) =A0I catched all of it alre= ady. >> >> Candidates are obviously SPEC and GCC itself. =A0I also use tramp3d >> of course. =A0That said, even if a pass does nearly nothing we often >> have testcases that need it ... > > True, but maybe those testcases should be adjusted--per-pass flags, > rather than blindly assuming -O2 includes them. =A0And it's not clear to It's easier to add things to GCC than to argue removing things ... > me that the statistics_counter_event infrastructure really helps > catching do-nothing passes, since it doesn't record stats that increment > by zero... Well, if the overall count is zero then nothing was done. Richard. > -Nathan >