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=-12.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 79784C4338F for ; Wed, 25 Aug 2021 12:57:19 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 EA60B61052 for ; Wed, 25 Aug 2021 12:57:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org EA60B61052 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ilande.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:56288 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mIsSz-0000HQ-Nb for qemu-devel@archiver.kernel.org; Wed, 25 Aug 2021 08:57:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49032) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mIsRy-000737-Mj; Wed, 25 Aug 2021 08:56:14 -0400 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:46650 helo=mail.default.ilande.bv.iomart.io) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mIsRw-0007yU-Vb; Wed, 25 Aug 2021 08:56:14 -0400 Received: from host86-179-186-93.range86-179.btcentralplus.com ([86.179.186.93] helo=[192.168.50.176]) by mail.default.ilande.bv.iomart.io with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1mIsRP-0009bN-5x; Wed, 25 Aug 2021 13:55:44 +0100 To: matheus.ferst@eldorado.org.br, qemu-devel@nongnu.org, qemu-ppc@nongnu.org References: <20210824201105.2303789-1-matheus.ferst@eldorado.org.br> From: Mark Cave-Ayland Message-ID: <1f5fe437-4839-c225-0859-91ccfa7532af@ilande.co.uk> Date: Wed, 25 Aug 2021 13:55:56 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20210824201105.2303789-1-matheus.ferst@eldorado.org.br> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 86.179.186.93 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: Re: [PATCH 0/2] target/ppc: Fix vextu[bhw][lr]x on big endian hosts X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.default.ilande.bv.iomart.io) Received-SPF: pass client-ip=2001:41c9:1:41f::167; envelope-from=mark.cave-ayland@ilande.co.uk; helo=mail.default.ilande.bv.iomart.io X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-2.24, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, groug@kaod.org, david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 24/08/2021 21:11, matheus.ferst@eldorado.org.br wrote: > From: Matheus Ferst > > The definition of struct Int128 is currently independent of the host > endianness, causing different results when using the member s128 of > union ppc_vsr_t in big-endian builds with CONFIG_INT128 or > !CONFIG_INT128. > > The only PPC instructions that seem to be affected by this issue are the > "Vector Extract Unsigned Byte/Halfword/Word to GPR using GPR-specified > Left/Right-Index." Even on builds with Int128 support, however, their > helpers give the wrong result on big-endian hosts. > > The first patch in this series changes the definition of struct Int128 > to allow its use in the ppc_vsr_t union. The second patch fixes the > helper definition. > > Matheus Ferst (2): > include/qemu/int128.h: define struct Int128 according to the host > endianness > target/ppc: fix vextu[bhw][lr]x helpers > > include/qemu/int128.h | 19 ++++++++++++------- > target/ppc/int_helper.c | 38 ++++++++++---------------------------- > 2 files changed, 22 insertions(+), 35 deletions(-) Hi Matheus, Slightly unrelated to this patchset, however I see you've managed to make some good efforts in consolidating the functionality between big-endian and little-endian host systems. When I first worked on adding host vector support for PPC I noticed there were some further places in target/ppc/int_helper.c that could be improved from accessing ppc_avr_t fields such as u64 directly and instead using the relevant Vsr*() macros. If you feel suitably motivated, it would be amazing to see more patches to help this further along: basically look in target/ppc/int_helper.c for individual elements such as u64 (and also the VECTOR_FOR_INORDER_I macro) and determine which ones are better replaced by the relevant Vsr*() macro. ATB, Mark.