From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263468AbUJ3Dgu (ORCPT ); Fri, 29 Oct 2004 23:36:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263470AbUJ3Dgu (ORCPT ); Fri, 29 Oct 2004 23:36:50 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:23258 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S263466AbUJ3Dfl (ORCPT ); Fri, 29 Oct 2004 23:35:41 -0400 Message-ID: <41830BFD.9030003@pobox.com> Date: Fri, 29 Oct 2004 23:35:25 -0400 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.3) Gecko/20040922 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Linus Torvalds CC: linux-os@analogic.com, Richard Henderson , Kernel Mailing List , Andi Kleen , Andrew Morton , Jan Hubicka Subject: Re: Semaphore assembly-code bug References: <417550FB.8020404@drdos.com> <1098218286.8675.82.camel@mentorng.gurulabs.com> <41757478.4090402@drdos.com> <20041020034524.GD10638@michonline.com> <1098245904.23628.84.camel@krustophenia.net> <1098247307.23628.91.camel@krustophenia.net> <20041029175527.GB25764@redhat.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > Anyway, it's quite likely that for several CPU's the fastest sequence ends > up actually being > > movl 4(%esp),%ecx > movl 8(%esp),%edx > movl 12(%esp),%eax > addl $16,%esp > > which is also one of the biggest alternatives. That's how I'm coding the sparse "compiler backend"... the mov's and add's tend to be tiny instructions (i-cache friendly), and you can often issue a bunch of them through multiple pipes/ports. Jeff