From: Theodore Tso Subject: Re: [PATCH,RFC] ext3: Add support for non-native signed/unsigned htree hash algorithms Date: Wed, 22 Oct 2008 22:56:47 -0400 Message-ID: <20081023025646.GD10369@mit.edu> References: <1224560624-9691-1-git-send-email-tytso@mit.edu> <1224560624-9691-2-git-send-email-tytso@mit.edu> <20081022172221.c1a8c5b5.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org To: Andrew Morton Return-path: Received: from www.church-of-our-saviour.ORG ([69.25.196.31]:49978 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751008AbYJWC4x (ORCPT ); Wed, 22 Oct 2008 22:56:53 -0400 Content-Disposition: inline In-Reply-To: <20081022172221.c1a8c5b5.akpm@linux-foundation.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, Oct 22, 2008 at 05:22:21PM -0700, Andrew Morton wrote: > > + if (((int) c) == -1) { > > arm says > > fs/ext3/super.c: In function `ext3_fill_super': > fs/ext3/super.c:1750: warning: comparison is always false due to limited range of data type > > Also, is there any way in which this new code can be, umm, cleaned up? Hmm..... is it considered safe to depend on the userspace limits.h header file? I guess if we trust that header file to be correct we could check the value of CHAR_MIN and/or CHAR_MAX as defined by limits.h. Alternatively we could do an #ifdef __CHAR_UNSIGNED__, which is defined by gcc. The manual for gcc tells us not to depend on it, but to depend on limits.h instead. Any thoughts, or comments? Does anyone know if the Intel compiler will DTRT with either of these approaches? - Ted