From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 2710DB708E for ; Tue, 30 Jun 2009 07:39:00 +1000 (EST) Received: from smtp-out.google.com (smtp-out.google.com [216.239.33.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 4BB08DDD04 for ; Tue, 30 Jun 2009 07:38:58 +1000 (EST) Received: from spaceape7.eur.corp.google.com (spaceape7.eur.corp.google.com [172.28.16.141]) by smtp-out.google.com with ESMTP id n5TLRsIX019187 for ; Mon, 29 Jun 2009 22:27:54 +0100 Received: from pzk16 (pzk16.prod.google.com [10.243.19.144]) by spaceape7.eur.corp.google.com with ESMTP id n5TLRokP032031 for ; Mon, 29 Jun 2009 14:27:51 -0700 Received: by pzk16 with SMTP id 16so420727pzk.0 for ; Mon, 29 Jun 2009 14:27:50 -0700 (PDT) To: David Howells Subject: Re: Inline Assembly queries References: <30098.1246291036@redhat.com> From: Ian Lance Taylor Date: Mon, 29 Jun 2009 14:27:48 -0700 In-Reply-To: <30098.1246291036@redhat.com> (David Howells's message of "Mon\, 29 Jun 2009 16\:57\:16 +0100") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: gcc-help@gcc.gnu.org, linuxppc-dev@ozlabs.org, kernel mailz List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , David Howells writes: > kernel mailz wrote: > >> asm("sync"); > > Isn't gcc free to discard this as it has no dependencies, no indicated side > effects, and isn't required to be kept? I think this should probably be: > > asm volatile("sync"); An asm with no outputs is considered to be volatile. Ian