Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933800Ab0KOWHT (ORCPT ); Mon, 15 Nov 2010 17:07:19 -0500 Received: from mail-gx0-f174.google.com ([209.85.161.174]:57998 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758614Ab0KOWHR convert rfc822-to-8bit (ORCPT ); Mon, 15 Nov 2010 17:07:17 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=b1NpbWLlFmHYieg+HWwPzHCa5SIxYfqum/h4p04s5NtvgDhIC8VUAgbiz4qSXlj5Jw D+5m6yLnV+1b9yTx4gc2q59CLEj8v25GzuaYH3l4MePh/TmnmduBLhn9yHmG4cLuAk1+ QZaF85nefgSyPJkChl0BNHjnGvBvKmvtJxVaw= MIME-Version: 1.0 In-Reply-To: <4CE17FB6.7000800@redhat.com> References: <4CD538CA.8010901@xs4all.nl> <87wroostw3.fsf@basil.nowhere.org> <87k4kospnd.fsf@basil.nowhere.org> <4CE17FB6.7000800@redhat.com> Date: Mon, 15 Nov 2010 23:07:15 +0100 Message-ID: Subject: Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? From: Richard Guenther To: Jeff Law Cc: Andi Kleen , Andreas Schwab , Jim , Linux Kernel Mailing List , gcc@gcc.gnu.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1165 Lines: 33 On Mon, Nov 15, 2010 at 7:45 PM, Jeff Law wrote: > On 11/08/10 03:49, Richard Guenther wrote: >> >> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen ?wrote: >>> >>> Andreas Schwab ?writes: >>>> >>>> The asm fails to mention that it modifies *regs. >>> >>> It has a memory clobber, that should be enough, no? >> >> No. ?A memory clobber does not cover automatic storage. > > A memory clobber should clobber anything in memory, including autos in > memory; if it doesn't, then that seems like a major problem. ?I'd like to > see the rationale behind not clobbering autos in memory. Non-address taken automatic storage. (note that we don't excercise this in optimization yet) It's difficult to model thins kind of non-aliased memory with this kind of aliasing mechanism (apart from taking all asms as clobbering everything as we currently do). Richard. > Jeff > -- 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/