From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18537 invoked by alias); 18 Dec 2012 17:25:59 -0000 Received: (qmail 18408 invoked by uid 55); 18 Dec 2012 17:25:38 -0000 From: "hubicka at ucw dot cz" To: gcc-bugs@gcc.gnu.org Subject: [Bug gcov-profile/55674] [4.8 Regression] >20% size increase of lto/pgo binaries since r193747 Date: Tue, 18 Dec 2012 17:25:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: gcov-profile X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: hubicka at ucw dot cz X-Bugzilla-Status: RESOLVED 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/msg01797.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55674 --- Comment #17 from Jan Hubicka 2012-12-18 17:25:37 UTC --- > I did some measurements with tramp3d and in this case > the default (999) gives the best performance: > > par. size time > -------------------- > 999 955859 3.71752 > 990 933390 3.73969 > 980 904718 3.84547 > ... " " > 750 904718 3.84769 > 740 837654 7.67177 > 600 836024 8.80879 Yep, tramp3d is unforutnately quite special case: we measure the number of instructions prior late optimization, while in tramp3d over 90% of code disappear as a result of inlining and further simplification, so we get GIGO problem... I am not sure how to handle these things in any resonable way.... I will test couple of values on spec2k this week and lets see how things scale elsewhere. Honza