From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6FD5189B97 for ; Tue, 17 Mar 2020 06:34:19 +0000 (UTC) Date: Tue, 17 Mar 2020 08:34:15 +0200 From: Petri Latvala Message-ID: <20200317063415.GF9497@platvala-desk.ger.corp.intel.com> References: <20200316161132.29833-1-lyude@redhat.com> <20200316161132.29833-5-lyude@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200316161132.29833-5-lyude@redhat.com> Subject: Re: [igt-dev] [PATCH i-g-t 4/4] meson: Add -fcommon to cc_flags List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" To: Lyude Cc: igt-dev@lists.freedesktop.org List-ID: On Mon, Mar 16, 2020 at 12:11:32PM -0400, Lyude wrote: > From: Lyude Paul > > Now that we've fixed a bunch of build breakages on systems where > -fcommon is the default (gcc 10+), let's start building with -fcommon by > default so we can make sure things don't break with this in the future. > Supposedly it's supposed to be able to generate better code anyway! The documentation claims otherwise, "on many targets implies a speed and code size penalty on global variable references". In fact the documentation even claims you get the multiple definition errors for variables with -fno-common and -fcommon helps avoiding them in legacy code! It's completely backwards to what happens. Oh well. With that said, the code was clearly wrong, thanks for the series. > > Signed-off-by: Lyude Paul Acked-by: Petri Latvala What this series proves is that no one is able to understand how tentative definitions and tentative declarations work in C. -- Petri Latvala _______________________________________________ igt-dev mailing list igt-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/igt-dev