Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754524Ab0KHLUI (ORCPT ); Mon, 8 Nov 2010 06:20:08 -0500 Received: from one.firstfloor.org ([213.235.205.2]:54202 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753289Ab0KHLUH (ORCPT ); Mon, 8 Nov 2010 06:20:07 -0500 From: Andi Kleen To: Richard Guenther Cc: Andreas Schwab , Jim , Linux Kernel Mailing List , gcc@gcc.gnu.org Subject: Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? References: <4CD538CA.8010901@xs4all.nl> <87wroostw3.fsf@basil.nowhere.org> <87k4kospnd.fsf@basil.nowhere.org> Date: Mon, 08 Nov 2010 12:20:02 +0100 In-Reply-To: (Richard Guenther's message of "Mon, 8 Nov 2010 11:49:13 +0100") Message-ID: <877hgorrj1.fsf@basil.nowhere.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 897 Lines: 28 Richard Guenther writes: > 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. That's a separate problem. > Btw, I can't see a testcase anywhere so I just assume Andreas got > it right as usual. An asm with live inputs and outputs should never be optimized way. If 4.5.1 started doing that it's seriously broken. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/