From patchwork Wed Jun 24 10:50:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 1316095 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=g8Hmfn43; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 49sKsh2G1Lz9sRR for ; Wed, 24 Jun 2020 20:59:36 +1000 (AEST) Received: from localhost ([::1]:56964 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jo37u-0000fv-2F for incoming@patchwork.ozlabs.org; Wed, 24 Jun 2020 06:59:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56626) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jo2zo-0001Dd-K1 for qemu-devel@nongnu.org; Wed, 24 Jun 2020 06:51:12 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:31582 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 1jo2zm-0001Kf-J6 for qemu-devel@nongnu.org; Wed, 24 Jun 2020 06:51:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592995869; 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=b/f+g1sL79bkK2ZcWOndgrRFIJ4GVzXBxsrToUJIrww=; b=g8Hmfn43bLAarDbAHKT+kk48fj7Up9VeL8rrcnCRWNdFfjH9xPvTqli+hamdknmJKVcuw3 76VuqvFkNdCTY029Jy6kaqZ4ocquz8x8oU9UgjOGk1N2/1Ny4DxLT78u9W4m5+MGWUMGF8 dHh4qk7OXb9Y1IA7/+j3qxMwrwe+UtQ= 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-366-xbfjNjHyNnm3LLxNatbclw-1; Wed, 24 Jun 2020 06:51:07 -0400 X-MC-Unique: xbfjNjHyNnm3LLxNatbclw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A789A18A8222; Wed, 24 Jun 2020 10:51:06 +0000 (UTC) Received: from virtlab511.virt.lab.eng.bos.redhat.com (virtlab511.virt.lab.eng.bos.redhat.com [10.19.152.198]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3A4CD5D9C5; Wed, 24 Jun 2020 10:51:06 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 16/31] softfloat: fix floatx80 remainder pseudo-denormal check for zero Date: Wed, 24 Jun 2020 06:50:33 -0400 Message-Id: <20200624105048.375353-16-pbonzini@redhat.com> In-Reply-To: <20200624104917.375143-1-pbonzini@redhat.com> References: <20200624104917.375143-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.120; envelope-from=pbonzini@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/24 03:27:53 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: Richard Henderson , Joseph Myers Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Joseph Myers The floatx80 remainder implementation ignores the high bit of the significand when checking whether an operand (numerator) with zero exponent is zero. This means it mishandles a pseudo-denormal representation of 0x1p-16382L by treating it as zero. Fix this by checking the whole significand instead. Signed-off-by: Joseph Myers Reviewed-by: Richard Henderson Message-Id: Signed-off-by: Paolo Bonzini --- fpu/softfloat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index b7dcf4d6c3..f164b5c0ad 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -5741,7 +5741,7 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, normalizeFloatx80Subnormal( bSig, &bExp, &bSig ); } if ( aExp == 0 ) { - if ( (uint64_t) ( aSig0<<1 ) == 0 ) return a; + if ( aSig0 == 0 ) return a; normalizeFloatx80Subnormal( aSig0, &aExp, &aSig0 ); } bSig |= UINT64_C(0x8000000000000000);