From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0445C43603 for ; Sun, 8 Dec 2019 08:48:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA89120637 for ; Sun, 8 Dec 2019 08:48:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726236AbfLHIsN (ORCPT ); Sun, 8 Dec 2019 03:48:13 -0500 Received: from mx2.suse.de ([195.135.220.15]:32932 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725832AbfLHIsN (ORCPT ); Sun, 8 Dec 2019 03:48:13 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id AAB74ABC4; Sun, 8 Dec 2019 08:48:11 +0000 (UTC) Date: Sun, 08 Dec 2019 09:48:11 +0100 Message-ID: From: Takashi Iwai To: Olof Johansson Cc: Jaroslav Kysela , Takashi Iwai , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ALSA: echoaudio: simplify get_audio_levels In-Reply-To: <20191207224953.25944-1-olof@lixom.net> References: <20191207224953.25944-1-olof@lixom.net> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 07 Dec 2019 23:49:53 +0100, Olof Johansson wrote: > > The loop optimizer seems to go astray here, and produces some warnings > that don't seem valid. > > Still, the code can be simplified -- just clear the whole array at the > beginning, and fill in whatever values are valid on the platform. > > Warnings before this change (GCC 8.2.0 ARM allmodconfig): > > In file included from ../sound/pci/echoaudio/gina24.c:115: > ../sound/pci/echoaudio/echoaudio.c: In function 'snd_echo_vumeters_get': > ../sound/pci/echoaudio/echoaudio_dsp.c:647:9: warning: iteration 1073741824 invokes undefined behavior [-Waggressive-loop-optimizations] > In file included from ../sound/pci/echoaudio/layla24.c:112: > ../sound/pci/echoaudio/echoaudio.c: In function 'snd_echo_vumeters_get': > ../sound/pci/echoaudio/echoaudio_dsp.c:658:9: warning: iteration 1073741824 invokes undefined behavior [-Waggressive-loop-optimizations] > ../sound/pci/echoaudio/echoaudio_dsp.c:647:9: warning: iteration 1073741824 invokes undefined behavior [-Waggressive-loop-optimizations] > > Signed-off-by: Olof Johansson Applied now, thanks. Takashi