From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 24 May 2002 12:45:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 24 May 2002 12:45:42 -0400 Received: from ns.caldera.de ([212.34.180.1]:57820 "EHLO ns.caldera.de") by vger.kernel.org with ESMTP id ; Fri, 24 May 2002 12:45:42 -0400 Date: Fri, 24 May 2002 18:45:37 +0200 Message-Id: <200205241645.g4OGjbE30934@ns.caldera.de> From: Marcus Meissner To: linux-kernel@vger.kernel.org Subject: Re: Compiling 2.2.19 with -O3 flag In-Reply-To: <1022253543.962.236.camel@sinai> User-Agent: tin/1.4.4-20000803 ("Vet for the Insane") (UNIX) (Linux/2.4.13 (i686)) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In article <1022253543.962.236.camel@sinai> you wrote: > On Fri, 2002-05-24 at 07:42, Alan Cox wrote: >> Bench it and see. From my own experience -O3 made the kernel a lot larger >> and reduced overall performance - in part because the kernel already >> explicitly figures out what it wants inlined. >> >> Interestingly enough -Os outperformed -O2 > Heh, now that is interesting. Not really, -Os implies -O2, cf gcc/toplev.c: if ((p[0] == 's') && (p[1] == 0)) { optimize_size = 1; /* Optimizing for size forces optimize to be 2. */ optimize = 2; } CIao, Marcus