From patchwork Thu May 12 19:42:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?V=C3=ADctor_Colombo?= X-Patchwork-Id: 12848073 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 08268C433FE for ; Thu, 12 May 2022 19:54:44 +0000 (UTC) Received: from localhost ([::1]:51556 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1npEtX-0007d4-Vc for qemu-devel@archiver.kernel.org; Thu, 12 May 2022 15:54:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40348) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1npEiU-0007w1-DW; Thu, 12 May 2022 15:43:19 -0400 Received: from [187.72.171.209] (port=25741 helo=outlook.eldorado.org.br) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1npEiQ-0003R0-4Z; Thu, 12 May 2022 15:43:16 -0400 Received: from p9ibm ([10.10.71.235]) by outlook.eldorado.org.br over TLS secured channel with Microsoft SMTPSVC(8.5.9600.16384); Thu, 12 May 2022 16:43:04 -0300 Received: from eldorado.org.br (unknown [10.10.70.45]) by p9ibm (Postfix) with ESMTP id 2979B800177; Thu, 12 May 2022 16:43:04 -0300 (-03) From: =?utf-8?q?V=C3=ADctor_Colombo?= To: qemu-devel@nongnu.org, qemu-ppc@nongnu.org Cc: clg@kaod.org, danielhb413@gmail.com, david@gibson.dropbear.id.au, groug@kaod.org, richard.henderson@linaro.org, victor.colombo@eldorado.org.br Subject: [RFC PATCH 0/2] target/ppc: Propose rework in fp exception handling Date: Thu, 12 May 2022 16:42:48 -0300 Message-Id: <20220512194250.138244-1-victor.colombo@eldorado.org.br> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-OriginalArrivalTime: 12 May 2022 19:43:04.0523 (UTC) FILETIME=[7F2C21B0:01D86638] X-Host-Lookup-Failed: Reverse DNS lookup failed for 187.72.171.209 (failed) Received-SPF: pass client-ip=187.72.171.209; envelope-from=victor.colombo@eldorado.org.br; helo=outlook.eldorado.org.br X-Spam_score_int: -4 X-Spam_score: -0.5 X-Spam_bar: / X-Spam_report: (-0.5 / 5.0 requ) BAYES_00=-1.9, PDS_HP_HELO_NORDNS=0.659, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hello everyone! I would like to propose a rework on the fpscr exceptions in fpu_helper.c. Today, we have: do_float_check_status() dealing with Overflow, Underflow, and Inexact; and other helpers for the invalid exceptions (like float_invalid_op_vximz(), float_invalid_op_vxisi()), including some special cases like float_invalid_op_madd(). So, there is a lot of helpers that may need to be used in the insn helpers code. My idea is try to find a way to concentrate them in a single place. This RFC moves imz, isi, and snan excp helpers to do_float_check_status as a hub for dealing with the commitment of exception flags from env->fp_status to env->fpscr. Then, show how an instruction could benefit of this change by adapting VSX_MADD helper to leverage the changes. The main objectives with this patch set are: 1. Try to simplify the excp handling code. 2. Allow for MMA instruction XVFGER to be easily implemented (see [1]) This RFC is just a subset of what I think should be done. There are more exceptions to be moved to do_float_check_status, and many more instructions to refactor to use it. Thanks! Based-on the FI bit fix [2]. [1] https://lists.gnu.org/archive/html/qemu-ppc/2022-05/msg00176.html [2] <20220510204610.100867-1-victor.colombo@eldorado.org.br> https://lists.nongnu.org/archive/html/qemu-ppc/2022-05/msg00246.html https://patchew.org/QEMU/20220510204610.100867-1-victor.colombo@eldorado.org.br/ Víctor Colombo (2): target/ppc: Add invalid imz, isi and snan to do_float_check_status() target/ppc: Rely on do_float_check_status for VSX_MADD invalid excepts target/ppc/fpu_helper.c | 148 ++++++++++++++++++++++++++-------------- 1 file changed, 97 insertions(+), 51 deletions(-)