From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32410 invoked by alias); 9 Jan 2009 20:55:29 -0000 Received: (qmail 32365 invoked by uid 48); 9 Jan 2009 20:55:18 -0000 Date: Fri, 09 Jan 2009 20:55:00 -0000 Message-ID: <20090109205518.32364.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/38785] huge performance regression on EEMBC bitmnp01 In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "steven at gcc dot gnu dot org" 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: 2009-01/txt/msg01026.txt.bz2 ------- Comment #5 from steven at gcc dot gnu dot org 2009-01-09 20:55 ------- Joern, re. comment #4, Richi refers to my patch to enable PRE at -Os, see [1]. An extension to this patch that we tested on x86 machines, is to disable PRE for scalar integer registers, via SMALL_REGISTER_CLASSES. I changed SMALL_REGISTER_CLASSES into a target hook for this purpose, see [2]. You could play with this, see if you can use this to cure your problem... [1] http://gcc.gnu.org/ml/gcc-patches/2008-12/msg00199.html [2] http://gcc.gnu.org/ml/gcc-patches/2008-12/msg00590.html -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38785