From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by sourceware.org (Postfix) with ESMTPS id 04565385E027 for ; Mon, 23 Mar 2020 10:28:02 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 04565385E027 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mliska@suse.cz X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id E78B8ADF1; Mon, 23 Mar 2020 10:28:00 +0000 (UTC) Subject: Re: [PATCH] Check endianess detection. To: Jakub Jelinek Cc: gcc-patches@gcc.gnu.org References: <82f5cda2-97f4-039e-5094-c528b220eb78@suse.cz> <20200323094308.GD2156@tucnak> <20200323101025.GE2156@tucnak> From: =?UTF-8?Q?Martin_Li=c5=a1ka?= Message-ID: <7a5da5ef-1f97-c273-ca22-7621c419f1c3@suse.cz> Date: Mon, 23 Mar 2020 11:28:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200323101025.GE2156@tucnak> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-23.2 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Mar 2020 10:28:04 -0000 On 3/23/20 11:10 AM, Jakub Jelinek wrote: > On Mon, Mar 23, 2020 at 11:00:21AM +0100, Martin Liška wrote: >> On 3/23/20 10:43 AM, Jakub Jelinek wrote: >>> On Mon, Mar 23, 2020 at 10:25:32AM +0100, Martin Liška wrote: >>>> Hi. >>>> >>>> As seen in the PR, sparc64 LTO test-suite fails due to missing >>>> definition of __BIG_ENDIAN__ macro. That said, I updated the >>>> endianess detection to use __BYTE_ORDER__. >>>> >>>> I tested the detection on x86_64-linux-gnu, ppc64-linux-gnu and >>>> lto.exp testsuite survives on a sparc64-linux machine. >>> >>> Those are GCC specific macros, are you sure plugin-api.h will be always >>> compiled just with GCC and no other compiler? >> >> And Clang supports that. The header file is used for GCC LTO plug-in >> (which is like a run-time library) and then it's consumed by binutils. >> So I don't how much portable it should be? > > GCC only supports that since GCC 4.6 and Clang copied that from that. > If it is only used in the LTO plugin and nothing else, I guess you can rely > in it being compiled by GCC only, but if it is e.g. used by binutils itself > too, then no. All right... > >>> You can use them but should be prepared for some fallback (e.g. endian.h, >>> whatever else). >>> And there is also PDP endian... >> >> Huh, are we talking about something so complex like: >> https://github.com/llvm-mirror/compiler-rt/blob/master/lib/builtins/int_endianness.h > > I'd say even that is very simplified. E.g. on glibc there is > with its macros, etc. > >> Btw. do we force our run-time libraries to be built with GCC? > > Some of our run-time libraries rely on being built by GCC, sure. > But I thought include/ is shared with binutils and there we don't really say > which compiler must be used to compile it. ... and can we then rely on configure detection of the endianess done by bfd and gold: gold/config.h:#define GOLD_DEFAULT_BIG_ENDIAN false bfd/PORTING: TARGET_IS_BIG_ENDIAN_P Should be defined if is big-endian. ? Martin > > Jakub >