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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 73568C433DF for ; Tue, 19 May 2020 18:32:49 +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 511DC2075F for ; Tue, 19 May 2020 18:32:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 511DC2075F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47382 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jb72m-0005YH-8Y for qemu-devel@archiver.kernel.org; Tue, 19 May 2020 14:32:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42486) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jb6yk-0001XR-4a for qemu-devel@nongnu.org; Tue, 19 May 2020 14:28:38 -0400 Received: from esa4.mentor.iphmx.com ([68.232.137.252]:5934) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jb6yi-0000vl-0d for qemu-devel@nongnu.org; Tue, 19 May 2020 14:28:37 -0400 IronPort-SDR: 1MBPt1kyS3eb1+fN2HAKKaCbG+BNUX1yd73SI20Pp/49KIMxKDNHoIFtRGZWExWkseP5qhIQ7z XWOcCJY8W6a9yOv2Ppytre9S9+Gqgizu4hwd39P7D9Lag7NBuREg6D/9HIaIubxsKM3nr8DFsf c/u03QcVfyHLAjLoI+6LGPSCaiM9NGIniIdHgPsSxzoz15BNTti2c8TVFpnhJZIDAWovmO0/S0 xyTTgt4uXP6X9pAMdNie/+Xb0c4k6+hIGEtE9d3v1AQ2BWUmDhUykaanE/C+R8u3F42ub3mETz nZM= X-IronPort-AV: E=Sophos;i="5.73,410,1583222400"; d="scan'208";a="49058277" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa4.mentor.iphmx.com with ESMTP; 19 May 2020 10:28:33 -0800 IronPort-SDR: 0+uHDvnzbK8sRSXuXv/CkTfFkNfEXSPcXum0pbYsVvpfDu4HvQzLTD+5gF/Brp9SjO/BzvY/X0 UnoRS6Fo6uCCrXg29zDQiaU9pQvdyZaFuqQjybCEhKxwCQvrS7kjsIon8C/d4eUG9DRozPQUsN KhdGDR2/j5YwaldxvOaREi6Unke95cFxl8VInjeo07ZDlh/vUoBNdLbxSU5DvAJG7CDBwVRjis 0Msc1I8b+qa9eVpOlH7j41UMRk3mb2uQrA1xX3oI5hZTuigJuCXSMcZ/FGGnDtJn7MWNDRIq3o Xp8= Date: Tue, 19 May 2020 18:28:27 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Richard Henderson Subject: Re: [PATCH 2/2] target/i386: fix IEEE x87 floating-point exception raising In-Reply-To: <76d7fa28-5dd9-3af4-f663-d251bbdbf4f4@linaro.org> Message-ID: References: <5dd2d81c-cedd-7835-6b3c-7e089254dc95@linaro.org> <76d7fa28-5dd9-3af4-f663-d251bbdbf4f4@linaro.org> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: SVR-IES-MBX-07.mgc.mentorg.com (139.181.222.7) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) Received-SPF: pass client-ip=68.232.137.252; envelope-from=joseph_myers@mentor.com; helo=esa4.mentor.iphmx.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/19 14:28:33 X-ACL-Warn: Detected OS = FreeBSD 9.x or newer [fuzzy] X-Spam_score_int: -39 X-Spam_score: -4.0 X-Spam_bar: ---- X-Spam_report: (-4.0 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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: pbonzini@redhat.com, qemu-devel@nongnu.org, ehabkost@redhat.com, rth@twiddle.net Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 19 May 2020, Richard Henderson wrote: > > Note that another bug in the x87 emulation is the lack of setting C1 for > > most instructions with inexact results based on the direction of rounding > > (which will require a new feature to be added to the softfloat code to > > record that information so the x87 emulation can use it). > > Wow, I don't believe I ever knew about that detail. musl libc uses it to get correctly rounded double-precision sqrt with x87 arithmetic. (glibc instead temporarily sets the rounding precision to achieve the same goal.) -- Joseph S. Myers joseph@codesourcery.com