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=-2.3 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 E923EC31E40 for ; Tue, 6 Aug 2019 08:31:38 +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 BD466206A2 for ; Tue, 6 Aug 2019 08:31:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Nh5seEsf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD466206A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+infradead-linux-riscv=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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=E6bNOOVvO/TTakhKF4bd0lQb+hBYShC6UygAQDVfc5Q=; b=Nh5seEsfn8w9hC F2dr483X5BdC3/2D3Sz3xnUOn7v+oOrX7SdegVbx80+4gfBK33ZPI3jAzXCMerTZwjrcLMxEUS5tT jYaxCnETnsdKYiATnlvvxa56EOZ67gajjZbuDdj4wfsou525s0QOZNgotBq5l6vuxPSkzAk4UdBfI fO7miaT7ijfUWjpFS3flpN0o8pE9OjVy2EdCab4pYAAl3Xr/lclPdMqoFOmlULXT6VvZOvNAbctoh 26jsar/P2n3qrEgtyEKIqx3I7VYYIbbSBAXi0nysQNK2mcZJOinjIs2tKOYDyraXVKHTc7R7qUHop /o4FECSw/zsoqL/oKK4Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1huusb-0004Ua-Qg; Tue, 06 Aug 2019 08:31:37 +0000 Received: from hch by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1huusZ-0004UQ-TB; Tue, 06 Aug 2019 08:31:35 +0000 Date: Tue, 6 Aug 2019 01:31:35 -0700 From: Christoph Hellwig To: Jim Wilson Subject: Re: About __udivdi3 Message-ID: <20190806083135.GA12410@infradead.org> References: <20190805055844.GE4292@andestech.com> <20190806013723.GA5417@andestech.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.4 (2019-03-13) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eric Lin , dslin1010@gmail.com, alankao@andestech.com, Palmer Dabbelt , rick@andestech.com, kclin@andestech.com, Paul Walmsley , linux-riscv@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+infradead-linux-riscv=archiver.kernel.org@lists.infradead.org On Mon, Aug 05, 2019 at 08:01:27PM -0700, Jim Wilson wrote: > On Mon, Aug 5, 2019 at 7:13 PM Paul Walmsley wrote: > > > > It seems __udivdi3 only supports 64-bit platform. > > > > Do you have any comments? Thanks. > > > > It sounds like you're describing a potential issue with gcc, rather than > > the kernel. If that's so, then the gcc mailing list(s) would be a better > > place to discuss this: https://gcc.gnu.org/lists.html > > The kernel doesn't link with libgcc.a. It has its own copy of udivdi3 > when needed. Linus still maintains his stance to not support 64 by 64-bit divisions on 32-bit platforms, and thus Linux does not support it. You can do 64 by 32-bit divisions using the awkward do_div macros, but that's it. This is supposed to apply to all 32-bit platforms, not just RISC-V. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv