Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263542AbTENSmN (ORCPT ); Wed, 14 May 2003 14:42:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263567AbTENSmN (ORCPT ); Wed, 14 May 2003 14:42:13 -0400 Received: from deviant.impure.org.uk ([195.82.120.238]:47835 "EHLO deviant.impure.org.uk") by vger.kernel.org with ESMTP id S263542AbTENSmK (ORCPT ); Wed, 14 May 2003 14:42:10 -0400 Date: Wed, 14 May 2003 19:55:39 +0100 From: Dave Jones To: Thomas Horsten Cc: LKML , "H . Peter Anvin" , Michael Elizabeth Chastain Subject: Re: [PATCH] 2.5.69 Changes to Kconfig and i386 Makefile to include support for various K7 optimizations Message-ID: <20030514185539.GA25542@suse.de> Mail-Followup-To: Dave Jones , Thomas Horsten , LKML , "H . Peter Anvin" , Michael Elizabeth Chastain References: <200305071834.26789.thomas@horsten.com> <20030514160449.B28115@suse.de> <200305141940.10999.thomas@horsten.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200305141940.10999.thomas@horsten.com> User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1186 Lines: 26 On Wed, May 14, 2003 at 07:40:10PM +0100, Thomas Horsten wrote: > I think when GCC supports the different cores, it should be supported by the > kernel scripts, the differences between the cores are real enough to have > potential optimizations at least in theory (as far as I could see the only > difference in GCC 3.2 is whether to use SSE, but that could change in the > future). To use SSE in kernel space, we need to wrap it in kernel_fpu_begin() / kernel_fpu_end() pairs anyway. gcc doesn't (and can't) know this. > I think it's a fairly simple patch that doesn't break anything it's non-obvious that it'll break things when people use broken compilers. read what I wrote before, several gcc versions got this horribly wrong. "athlon4" was even tuned for 64bit at one point. Take away the SSE, take away the broken compiler versions, and you'd be left with something that would hardly show a blip on a benchmark. Dave - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/