Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756051AbXIOUB2 (ORCPT ); Sat, 15 Sep 2007 16:01:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753389AbXIOUBV (ORCPT ); Sat, 15 Sep 2007 16:01:21 -0400 Received: from one.firstfloor.org ([213.235.205.2]:52787 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753251AbXIOUBU (ORCPT ); Sat, 15 Sep 2007 16:01:20 -0400 Date: Sat, 15 Sep 2007 22:01:17 +0200 From: Andi Kleen To: Serge Belyshev Cc: Andi Kleen , patches@x86-64.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH]: x86_64: Remove unnecessary cast in prefetch() Message-ID: <20070915200117.GC14501@one.firstfloor.org> References: <87tzq7cwnt.fsf@depni.sinp.msu.ru> <200709070818.03995.ak@suse.de> <878x78ig85.fsf@depni.sinp.msu.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <878x78ig85.fsf@depni.sinp.msu.ru> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1000 Lines: 29 On Sat, Sep 15, 2007 at 10:40:26AM +0400, Serge Belyshev wrote: > Andi Kleen writes: > > >> This can be fixed better by using gcc's __builtin_prefetch(). > > > > I changed it to just use that. Thanks. > > > > It seems like gcc 3.1/3.2 already supported it and that's the earliest gcc > > still supported so it can be used unconditionally. > > > > Hi! > > Will you submit this patch for inclusion into 2.6.23? It is important Didn't plan it currently. > to make kernel work with GCC 4.3 and above. (Also note that gcc 4.2 already > smart enough to break that code, but kernel is just lucky currently). How would it break the code exactly? It more sounded like an optimization to me. Would it generate incorrect code without it? -Andi - 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/