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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 283B5C38142 for ; Tue, 31 Jan 2023 16:20:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=t83FaYRIBkguZSkTuTenE7E0LzbaqPZxCdPVfxOvDJY=; b=WUFH0DN8fvy8ro QQ7uBpQhnBk/anvlhLkC/jmVqgUAIkPKo5/UHZwMqOpHQWlhz7UHfcR6W8oKhydxQNx1eM9D90Y4j BSNuAJFptpdnhjQp91tezspmTWO1lza/kNyZREx48XgK76v3qxpIFa2MjjndP+aTI7l1pVFlzEuzO gfEqdNkdx4poLGpw4SPuN2NzgjQq/qq/8m1epYMXMxs3h0VYln8bO5ztr3wnCqZyh0Xtt5ve+a1cU OTdpeA3zvj0iDD49anXtsix9yWmJ933lopDb3dLqBal9VDmjBqcPclSWsY1JmEFoZ1Uc21aOdP84w axKklok71WfDqYMFgkQA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMtLp-008fBx-Ez; Tue, 31 Jan 2023 16:19:17 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMtLm-008fBH-J0 for linux-arm-kernel@lists.infradead.org; Tue, 31 Jan 2023 16:19:15 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id CE923B80FED; Tue, 31 Jan 2023 16:19:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29B7EC433EF; Tue, 31 Jan 2023 16:19:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675181951; bh=5Ro9I1IdyUJ8Up/SzCY9kO7TLB9c+8pxMOs81oWI4TQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pYTzmZ32/IGB5vXXrmCqiDqakKbPs6Zqb8O+srgi0faTbWM1ZO1W0Oi00P6Chtmxl Y///LeZMU5ilSui3tsSBYB+zFaGj4ySpCE8/pXC1yNJk92ZhmygMagi9akRuL6SU/h Rp0hoD1guzpluqISlbyCJJcyAmG5iBWLYFC0rxum6rs0nSIT+W4kNgbe+2iKdQrQfj NmUM+VGnoMTILc/BrHcTEr5x5JxEvvNLO5aaoIyrwW9GQowFJAxX5+XaZkywM6Vscx BGvpipZA80Vu5zGGSQyuADtkMNDIGnxEDX3qrPV1hnRS/WYmTYTZbCfMvTyUuwD+bD Cy6Z+W2/vp76g== Date: Tue, 31 Jan 2023 16:19:06 +0000 From: Will Deacon To: Miguel Ojeda Cc: Jamie Cunliffe , linux-arm-kernel@lists.infradead.org, rust-for-linux@vger.kernel.org, Miguel Ojeda , Catalin Marinas , steve.capper@arm.com Subject: Re: [PATCH 1/3] arm64: rust: Enable Rust support for AArch64 Message-ID: <20230131161905.GC2646@willie-the-truck> References: <20230125163739.3798252-1-Jamie.Cunliffe@arm.com> <20230125163739.3798252-2-Jamie.Cunliffe@arm.com> <20230126163552.GD29438@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230131_081914_794329_F25F1297 X-CRM114-Status: GOOD ( 20.44 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jan 26, 2023 at 06:56:01PM +0100, Miguel Ojeda wrote: > On Thu, Jan 26, 2023 at 5:35 PM Will Deacon wrote: > > > > Why do we need to specify this stuff here? LLVM already knows about AArch64 > > and can compute the data-layout string in computeDataLayout(). Can we have > > the tools figure this out for us instead, please? > > I agree -- the reason we have this for the moment is to provide full > control of the target spec, in particular for cases where `rustc` may > not provide enough flags to customize exiting builtin target specs > and/or may emit warnings for unknown target features etc. > > If it is already enough for arm64 to use e.g. the > `aarch64-unknown-none` target spec plus flags on top, then we should > go for that, because that is the end goal: these target spec files are > unstable in the Rust compiler (and not intended to become stable). Please confirm that this is the case, but I really think we should be aiming for that rather than starting off my specifying this stuff manually. > For context, upstream Rust so far has been willing to merge support > for flags and target features that we needed, which is great. One thing I ran into while playing around is that 128-bit types aren't supported with ffi unless '-A improper-ctypes' is passed. Given that we use '__uint128_t' to represent the fpsimd state, I think this is probably something which will crop up as an issue. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel