From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261636AbVGSUMF (ORCPT ); Tue, 19 Jul 2005 16:12:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261687AbVGSUME (ORCPT ); Tue, 19 Jul 2005 16:12:04 -0400 Received: from mail-in-02.arcor-online.net ([151.189.21.42]:37030 "EHLO mail-in-02.arcor-online.net") by vger.kernel.org with ESMTP id S261636AbVGSULc (ORCPT ); Tue, 19 Jul 2005 16:11:32 -0400 From: Bodo Eggert Subject: Re: Noob question. Why is the for-pentium4 kernel built with -march=i686 ? To: ivan@yosifov.net, Jan Engelhardt , linux-kernel@vger.kernel.org Reply-To: 7eggert@gmx.de Date: Tue, 19 Jul 2005 22:12:24 +0200 References: <4s3M3-ph-15@gated-at.bofh.it> <4s4y2-Rt-17@gated-at.bofh.it> <4s5aD-1sw-3@gated-at.bofh.it> User-Agent: KNode/0.7.2 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8Bit Message-Id: X-be10.7eggert.dyndns.org-MailScanner-Information: See www.mailscanner.info for information X-be10.7eggert.dyndns.org-MailScanner: Found to be clean X-be10.7eggert.dyndns.org-MailScanner-From: harvested.in.lkml@posting.7eggert.dyndns.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ivan Yosifov wrote: > -march implies -mtune and also implies thing like -msse2 for the > instruction set where applicable. > I think -march=pentium4 is equivalent to -mmmx -msse -msse2 > -mtune=pentium4 ( if I have not fogotten anything ). > Pentium4 supports things like sse2 and mmx which AFAIK plain i686 does > not. AFAIK it's not possible to use SSE and MME in kernel mode, since these registers aren't preserved (it would be expensive). -- Ich danke GMX dafür, die Verwendung meiner Adressen mittels per SPF verbreiteten Lügen zu sabotieren.