From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by sourceware.org (Postfix) with ESMTP id CBB98385DC00; Sun, 31 May 2020 20:42:41 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org CBB98385DC00 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=segher@kernel.crashing.org Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 04VKg7G6016005; Sun, 31 May 2020 15:42:07 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 04VKg5KW016002; Sun, 31 May 2020 15:42:05 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Sun, 31 May 2020 15:42:05 -0500 From: Segher Boessenkool To: Will Springer Cc: linuxppc-dev@lists.ozlabs.org, libc-alpha@sourceware.org, eery@paperfox.es, daniel@octaforge.org, musl@lists.openwall.com, binutils@sourceware.org, libc-dev@lists.llvm.org Subject: Re: ppc64le and 32-bit LE userland compatibility Message-ID: <20200531204205.GI31009@gate.crashing.org> References: <2047231.C4sosBPzcN@sheen> <20200530192212.GG31009@gate.crashing.org> <2956705.fEcJ0Lxnt5@sheen> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2956705.fEcJ0Lxnt5@sheen> User-Agent: Mutt/1.4.2.3i X-Spam-Status: No, score=-12.6 required=5.0 tests=BAYES_00, JMQ_SPF_NEUTRAL, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, TXREP, T_SPF_HELO_PERMERROR, T_SPF_PERMERROR autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: binutils@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Binutils mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 31 May 2020 20:42:43 -0000 On Sun, May 31, 2020 at 12:57:12AM +0000, Will Springer wrote: > On Saturday, May 30, 2020 12:22:12 PM PDT Segher Boessenkool wrote: > > The original sysv PowerPC supplement > > http://refspecs.linux-foundation.org/elf/elfspec_ppc.pdf > > supports LE as well, and most powerpcle ports use that. But, the > > big-endian Linux ABI differs in quite a few places, and it of course > > makes a lot better sense if powerpcle-linux follows that. > > Right, I should have clarified I was talking about Linux ABIs > specifically. That was the link you deleted. > > What patches did you need? I regularly build >30 cross compilers (on > > both BE and LE hosts; I haven't used 32-bit hosts for a long time, but > > in the past those worked fine as well). I also cross-built > > powerpcle-linux-gcc quite a few times (from powerpc64le, from powerpc64, > > from various x86). > > There was just an assumption that LE == powerpc64le in libgo, spotted by > q66 (daniel@ on the CC). I just pushed the patch to [1]. Please send GCC patches to gcc-patches@ ? > > Almost no project that used 32-bit PowerPC in LE mode has sent patches > > to the upstreams. > > Right, but I have heard concerns from at least one person familiar with > the ppc kernel about breaking existing users of this arch-endianness > combo, if any. It seems likely that none of those use upstream, though ^^; So we don't care, because we *cannot* care. > > A huge factor in having good GCC support for powerpcle-linux (or > > anything else) is someone needs to regularly test it, and share test > > results with us (via gcc-testresults@). Hint hint hint :-) > > > > That way we know it is in good shape, know when we are regressing it, > > know there is interest in it. > > Once I have more of a bootstrapped userland than a barely-functional > cross chroot, I'll get back to you on that :) Cool! Looking forward to it. Thanks, Segher