Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755486AbZJZKIc (ORCPT ); Mon, 26 Oct 2009 06:08:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755477AbZJZKIb (ORCPT ); Mon, 26 Oct 2009 06:08:31 -0400 Received: from fg-out-1718.google.com ([72.14.220.157]:37532 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755473AbZJZKIa convert rfc822-to-8bit (ORCPT ); Mon, 26 Oct 2009 06:08:30 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=DGgZaziyV4Ld75lUu0jTWsCk9a7vHrSzzbKdotyzUiWB3Rf5+HEam1ClYQ7LIbJaSK toSLNJxuqDaBPIi/QFlGIeaNu/yyMm2WhDvFb1otS4Ps+D2AzFkM0biIhKEMVibZUH/H NAc7bDNPFqO/f1BRha+hbR/MMvyuz/ET7w0Kg= MIME-Version: 1.0 In-Reply-To: <20091026094729.GB13517@linux-sh.org> References: <20091026054000.GA13517@linux-sh.org> <20091026062520.GA29580@elte.hu> <20091026094729.GB13517@linux-sh.org> Date: Mon, 26 Oct 2009 12:08:34 +0200 X-Google-Sender-Auth: a9be069eae1e7d85 Message-ID: <84144f020910260308r106574e3vdd72e8697571bdc2@mail.gmail.com> Subject: Re: [PATCH] perf tools: Kill off -Wcast-align From: Pekka Enberg To: Paul Mundt Cc: Ingo Molnar , linux-kernel@vger.kernel.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: 1910 Lines: 39 * Paul Mundt wrote: >> > The present use of -Wcast-align causes the build to blow up on SH due to >> > generating a "cast increases required alignment of target type" error on >> > each invocation of list_for_each_entry(). >> > >> > It seems that this was previously reported and killed off in the ia64 >> > support patch, but nothing seems to have happened with that. Presumably >> > the same problem still remains there, too. >> > >> > Signed-off-by: Paul Mundt On Mon, Oct 26, 2009 at 07:25:20AM +0100, Ingo Molnar wrote: >> Is this a GCC bug producing false positive warnings? The GCC manpage >> says: >> >> ? ? ? ?-Wcast-align >> ? ? ? ? ? ?Warn whenever a pointer is cast such that the required alignment of the >> ? ? ? ? ? ?target is increased. ?For example, warn if a "char *" is cast to an >> ? ? ? ? ? ?"int *" on machines where integers can only be accessed at two- or >> ? ? ? ? ? ?four-byte boundaries. >> >> Which looks moderately useful - if it works. On Mon, Oct 26, 2009 at 11:47 AM, Paul Mundt wrote: > Well, both ia64 and sh have hit this in the current compilers, and it > doesn't seem to pose any code generation issues. In the areas where it is > generated it seems to relate to 64-bit data types in the data structures, > which in itself doesn't seem inherently problematic. > > I'll submit a bug report to the GCC folks, but for the time being given > that multiple architectures are hitting this and it doesn't seem to be > causing any issues, it would be better to have this flag dropped. Can we disable the flag for affected architectures but keep it enabled for x86? -- 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/