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 3FBB9C4332F for ; Fri, 16 Dec 2022 19:45:45 +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-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:Cc:To:From :Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=pL2vudLiDn4zVI49tAAmxbnFurSaeoFH+0rC0FvZ3Lc=; b=FpT+yzbym9Yriz6yIEsItAkxPk v32fBjKbBq3o1GGcsKdoePXnEel8bbvVHL0kwZdOr0i1RYwnTbo+kp06zgnK3dR6gcMSFE70eHqv+ vVXYQRz03O5hv5ex5cdlchXnEsHw6HG9dRYBH2rqW9mTDTax1nIPwqswCno8GusTgTyiOUtFkMUmk nOgenQ54w3OOZsC0RFmd5A7G2e24anU+/6J6TNXu7YVN1L5s3aJ33ydRG0X6AsCyby0deFy671bLu qZiZL2WUgdGpNdR8wTnwgGhMkyE/v6fUQKIP/vj0hwlhJV8iOWDsbjjyeIY7ZP/TNRc0pY5w/iG/t 3ZqHTK6A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p6GeF-000K56-8O; Fri, 16 Dec 2022 19:45:35 +0000 Received: from imap5.colo.codethink.co.uk ([78.40.148.171]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p6GeD-000K1Q-0D for linux-riscv@lists.infradead.org; Fri, 16 Dec 2022 19:45:34 +0000 Received: from [78.40.148.178] (helo=webmail.codethink.co.uk) by imap5.colo.codethink.co.uk with esmtpsa (Exim 4.94.2 #2 (Debian)) id 1p6Ge1-00BQ4s-8w; Fri, 16 Dec 2022 19:45:21 +0000 MIME-Version: 1.0 Date: Fri, 16 Dec 2022 19:45:21 +0000 From: Ben Dooks To: Saleem Abdulrasool Cc: Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] riscv: avoid enabling vectorized code generation In-Reply-To: <20221216185012.2342675-1-abdulras@google.com> References: <20221216185012.2342675-1-abdulras@google.com> Message-ID: <39636675da60fc6c54cc8bbab64ddbac@codethink.co.uk> X-Sender: ben.dooks@codethink.co.uk X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221216_114533_072577_494077A3 X-CRM114-Status: UNSURE ( 7.77 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On 2022-12-16 18:50, Saleem Abdulrasool wrote: > The compiler is free to generate vectorized operations for zero'ing > memory. The kernel does not use the vector unit on RISCV, similar to > architectures such as x86 where we use `-mno-mmx` et al to prevent the > implicit vectorization. Perform a similar check for > `-mno-implicit-float` to avoid this on RISC-V targets. I'm not sure if we should be emitting either of the vector or floating point instrucitons in the kernel without explicitly marking the section of code which is using them such as specific accelerator blocks. -- Ben _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB953C4332F for ; Fri, 16 Dec 2022 19:45:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232022AbiLPTpe (ORCPT ); Fri, 16 Dec 2022 14:45:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229583AbiLPTpb (ORCPT ); Fri, 16 Dec 2022 14:45:31 -0500 Received: from imap5.colo.codethink.co.uk (imap5.colo.codethink.co.uk [78.40.148.171]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C423F02D for ; Fri, 16 Dec 2022 11:45:29 -0800 (PST) Received: from [78.40.148.178] (helo=webmail.codethink.co.uk) by imap5.colo.codethink.co.uk with esmtpsa (Exim 4.94.2 #2 (Debian)) id 1p6Ge1-00BQ4s-8w; Fri, 16 Dec 2022 19:45:21 +0000 MIME-Version: 1.0 Date: Fri, 16 Dec 2022 19:45:21 +0000 From: Ben Dooks To: Saleem Abdulrasool Cc: Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] riscv: avoid enabling vectorized code generation In-Reply-To: <20221216185012.2342675-1-abdulras@google.com> References: <20221216185012.2342675-1-abdulras@google.com> Message-ID: <39636675da60fc6c54cc8bbab64ddbac@codethink.co.uk> X-Sender: ben.dooks@codethink.co.uk Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-12-16 18:50, Saleem Abdulrasool wrote: > The compiler is free to generate vectorized operations for zero'ing > memory. The kernel does not use the vector unit on RISCV, similar to > architectures such as x86 where we use `-mno-mmx` et al to prevent the > implicit vectorization. Perform a similar check for > `-mno-implicit-float` to avoid this on RISC-V targets. I'm not sure if we should be emitting either of the vector or floating point instrucitons in the kernel without explicitly marking the section of code which is using them such as specific accelerator blocks. -- Ben