From patchwork Thu Jun 11 19:43:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 280709 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 7C320C433E0 for ; Thu, 11 Jun 2020 20:16:22 +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 4712B206C3 for ; Thu, 11 Jun 2020 20:16:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TObTXdof" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4712B206C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34358 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jjTcb-0005sd-ES for qemu-devel@archiver.kernel.org; Thu, 11 Jun 2020 16:16:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54882) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jjT8v-0007uV-3x for qemu-devel@nongnu.org; Thu, 11 Jun 2020 15:45:41 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:36463 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jjT8s-00011r-1L for qemu-devel@nongnu.org; Thu, 11 Jun 2020 15:45:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591904737; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9MiZTuB1jn4OQN9DsLVSeuNz7XUvR6qH6PEUWfjPKZw=; b=TObTXdofZ5MKpmiRkQO9PkP3xszFjYMhP6HDIb4f9OVYz6JT1ntj3PmOxdLK7m55+JxIJR OVQxXv/g9wwXmENZNVr3pJO3jlWhKaRO5gDGHScAzidT6dmi8V+sSuayKedvDh3evLoR9S GJv4+B16HO+JUcXDq5D+MyvUpLWTh70= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-329-YsuNxs3hM4e08-P8UdY26g-1; Thu, 11 Jun 2020 15:45:34 -0400 X-MC-Unique: YsuNxs3hM4e08-P8UdY26g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E0153A0C00; Thu, 11 Jun 2020 19:45:33 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 231B8707C6; Thu, 11 Jun 2020 19:45:33 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 052/115] target/i386: fix fscale handling of signaling NaN Date: Thu, 11 Jun 2020 15:43:46 -0400 Message-Id: <20200611194449.31468-53-pbonzini@redhat.com> In-Reply-To: <20200611194449.31468-1-pbonzini@redhat.com> References: <20200611194449.31468-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.120; envelope-from=pbonzini@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/11 08:37:10 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-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: Joseph Myers Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Joseph Myers The implementation of the fscale instruction returns a NaN exponent unchanged. Fix it to return a quiet NaN when the provided exponent is a signaling NaN. Signed-off-by: Joseph Myers Message-Id: Signed-off-by: Paolo Bonzini --- target/i386/fpu_helper.c | 4 ++++ tests/tcg/i386/test-i386-fscale.c | 37 +++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) create mode 100644 tests/tcg/i386/test-i386-fscale.c diff --git a/target/i386/fpu_helper.c b/target/i386/fpu_helper.c index 568bd3b359..0671de6952 100644 --- a/target/i386/fpu_helper.c +++ b/target/i386/fpu_helper.c @@ -970,6 +970,10 @@ void helper_fscale(CPUX86State *env) { if (floatx80_is_any_nan(ST1)) { ST0 = ST1; + if (floatx80_is_signaling_nan(ST0, &env->fp_status)) { + float_raise(float_flag_invalid, &env->fp_status); + ST0 = floatx80_silence_nan(ST0, &env->fp_status); + } } else { int n = floatx80_to_int32_round_to_zero(ST1, &env->fp_status); ST0 = floatx80_scalbn(ST0, n, &env->fp_status); diff --git a/tests/tcg/i386/test-i386-fscale.c b/tests/tcg/i386/test-i386-fscale.c new file mode 100644 index 0000000000..aecac5125f --- /dev/null +++ b/tests/tcg/i386/test-i386-fscale.c @@ -0,0 +1,37 @@ +/* Test fscale instruction. */ + +#include +#include + +union u { + struct { uint64_t sig; uint16_t sign_exp; } s; + long double ld; +}; + +volatile long double ld_res; + +int isnan_ld(long double x) +{ + union u tmp = { .ld = x }; + return ((tmp.s.sign_exp & 0x7fff) == 0x7fff && + (tmp.s.sig >> 63) != 0 && + (tmp.s.sig << 1) != 0); +} + +int issignaling_ld(long double x) +{ + union u tmp = { .ld = x }; + return isnan_ld(x) && (tmp.s.sig & UINT64_C(0x4000000000000000)) == 0; +} + +int main(void) +{ + int ret = 0; + __asm__ volatile ("fscale" : "=t" (ld_res) : + "0" (2.5L), "u" (__builtin_nansl(""))); + if (!isnan_ld(ld_res) || issignaling_ld(ld_res)) { + printf("FAIL: fscale snan\n"); + ret = 1; + } + return ret; +}