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=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 661B5C43331 for ; Thu, 26 Mar 2020 19:10:42 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 34D76206E6 for ; Thu, 26 Mar 2020 19:10:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="MWJQzQvY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 34D76206E6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=csclub.uwaterloo.ca Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-snps-arc-bounces+linux-snps-arc=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:From:In-Reply-To:MIME-Version: References:Message-ID:Subject:To:Date:Reply-To:Cc:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=KeftoTGTABu0bC+lCUm1F2jNyGyb6n01aJvLCNhbdCM=; b=MWJQzQvYmPondVOEsarU4XFll2 FrwbACRP8z1wuleXU9+K2HeihAOJfPIwVHhKmquf45LONOuSPT0n3yczpssLNWGZWzOyZxrUIfRaf CfOGIhbHAne7FGsW7t4AgcOZcbFu28ssaYv2jxseTczPvbfRYOd6gVpbNHbtNWmpOqgmaEBzowNel KKuRFNcsIe6p4/+dUb6Eh5VboijoxlpjxKwyKi5S/BnDsXURdstOtkx73G5BM1OmMPJ8/4SdzY/NG ytmOTEHiEFLprwP9WI/6Iu2tvV9FKkzvrURqvzFkPG7DVLvtPlpv3ITwo63EJuR0Q0nf0WVga0zf2 Di2k90rA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jHXtp-0007P1-Hc; Thu, 26 Mar 2020 19:10:41 +0000 Received: from caffeine.csclub.uwaterloo.ca ([129.97.134.17]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jHXtn-0007OS-IX for linux-snps-arc@lists.infradead.org; Thu, 26 Mar 2020 19:10:40 +0000 Received: by caffeine.csclub.uwaterloo.ca (Postfix, from userid 20367) id 0387B46166D; Thu, 26 Mar 2020 15:04:28 -0400 (EDT) Date: Thu, 26 Mar 2020 15:04:28 -0400 To: Helmut Grohne , Alexey Brodkin , "debian-arm@lists.debian.org" , arcml , GNU C Library , Vineet Gupta , Claudiu Zissulescu , Vineet Gupta Subject: Re: ARC rebootstrap prereq (was Re: switching ARC to 64-bit time_t ) Message-ID: <20200326190428.dxgq6vetirgq5ixy@csclub.uwaterloo.ca> References: <8a9784b3-fc52-adc3-4595-33142b059388@synopsys.com> <20200220001136.2f14236e@jawa> <20200220162735.GA26634@alf.mars> <2c3d76a7-fa94-d16e-2803-a98a4761e427@gmail.com> <20200326055408.GA31088@alf.mars> <20200326122401.GA5669@alf.mars> <20200326142836.GA24503@alf.mars> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200326142836.GA24503@alf.mars> User-Agent: NeoMutt/20170113 (1.7.2) From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200326_121039_680825_90D42C23 X-CRM114-Status: GOOD ( 10.37 ) X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+linux-snps-arc=archiver.kernel.org@lists.infradead.org On Thu, Mar 26, 2020 at 03:28:36PM +0100, Helmut Grohne wrote: > One part of the question here is "why do we need libatomic-ops?". The > answer to that is, because libgc uses it and libgc is used by e.g. gcc, > gnutls, guile, and make. Possibly, some of these could be built without > libgc, but this is how they are packaged for Debian at present. Package > dependencies currently say that we need libatomic-ops. > > The other part is "what is missing in libatomic-ops"? If you look at a > more recent implementation, such as riscv, you see that it basically > says "trust gcc". So I guess all you need here is an arc-specific > implementation that says "gcc knows what it is doing, use its > primitives". > > Given sufficient work, I guess libatomic-ops could be removed in favour > of using the gcc built-ins directly. Not sure whether that'd fly with > libgc upstream though. > > So no, this is not a stupid question. Thank you for asking. The way I read the details on libatomic is that it provides functions to implement the things a given architecture can't do with intrinsics in gcc directly. So on some architectures it does nothing and on others it implements missing bits for atomic operations. -- Len Sorensen _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc