From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15494 invoked by alias); 4 Aug 2011 13:32:32 -0000 Received: (qmail 15473 invoked by uid 22791); 4 Aug 2011 13:32:31 -0000 X-SWARE-Spam-Status: No, hits=-2.2 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from nikam.ms.mff.cuni.cz (HELO nikam.ms.mff.cuni.cz) (195.113.20.16) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 04 Aug 2011 13:32:16 +0000 Received: by nikam.ms.mff.cuni.cz (Postfix, from userid 16202) id B6CCE9AC828; Thu, 4 Aug 2011 15:32:14 +0200 (CEST) Date: Thu, 04 Aug 2011 13:32:00 -0000 From: Jan Hubicka To: Xinliang David Li Cc: Jan Hubicka , Paolo Bonzini , Richard Henderson , "gcc@gcc.gnu.org" Subject: Re: [RFC] Remove -freorder-blocks-and-partition Message-ID: <20110804133214.GB12248@kam.mff.cuni.cz> References: <4E25F810.6050904@redhat.com> <4E2D4425.9040104@gnu.org> <20110803210614.GE22893@atrey.karlin.mff.cuni.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2011-08/txt/msg00093.txt.bz2 > On Wed, Aug 3, 2011 at 2:06 PM, Jan Hubicka wrote: > >> In xalancbmk, with the partition option, most of object files have > >> nonzero size cold sections generated. The text size of the binary is > >> increased to 3572728 bytes from 3466790 bytes.  Profiling the program > >> using the training input shows the following differences. With > >> partitioning, number of executed branch instructions slightly > >> increases, but itlb misses and icache load misses are significantly > >> lower compared with the binary without partitioning. > >> > >> > >> David > >> > >> With partition: > >> ----------------- > >>    53654937239  branches > >>       306751458  L1-icache-load-misses > >>         8146112  iTLB-load-misses > > > > Note that I was also planning for some time to introduce notion of provably cold > > stuff into our branch prediction heurstics. I.e. code leading to aborts, eh etc > > no-return attribute is looked at by static profile estimation pass. Is > the attribute (definitely not returning) properly propagated to the > callers (wrappers of exit, etc)? It is, at local pure const and IPA pure const. Catch with IPA pure const is that profile is computed at tha time and it is not updated afterwards, so when discovered late it does not affect static profile estimates (yet), only gets cfg/codegen better. Honza > > David > > > that can be then offlined even w/o profile feedback and could perhaps help > > to large apps. > > (also the whole pass should be more effective with larger testcases, SPEC2k6 is slowly > > becoming a small one) > > > > Honza > >