From patchwork Thu Dec 24 02:45:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Siddhesh Poyarekar X-Patchwork-Id: 41544 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id AB93A38930D5; Thu, 24 Dec 2020 02:46:17 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org AB93A38930D5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1608777977; bh=EWrSlev9oXO0ZFrIJh9bzgX3WyTOgz8qrpdGnE8L+wM=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=CWOkcq43EQ0J8bnB/RGeYd3cmxegv/ZvdLps8l/Y2Z85u4aUmPI+mcaYGvipPYl5s MVlVWhDOgiqFOVFNfkzOUDf6EOWrB6ISIA5xYkrKzD8x1WhpwbwI63PapkjJ0PmjB7 6PgjvCnHaM0WCQZEDDxSfA8nGSzAw64Q3mIhtb/c= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from duck.ash.relay.mailchannels.net (duck.ash.relay.mailchannels.net [23.83.222.52]) by sourceware.org (Postfix) with ESMTPS id A792B38930D5 for ; Thu, 24 Dec 2020 02:46:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A792B38930D5 X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 0FD81700D2C; Thu, 24 Dec 2020 02:46:11 +0000 (UTC) Received: from pdx1-sub0-mail-a69.g.dreamhost.com (100-96-27-97.trex.outbound.svc.cluster.local [100.96.27.97]) (Authenticated sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id 93579700E63; Thu, 24 Dec 2020 02:46:10 +0000 (UTC) X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from pdx1-sub0-mail-a69.g.dreamhost.com (pop.dreamhost.com [64.90.62.162]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384) by 0.0.0.0:2500 (trex/5.18.11); Thu, 24 Dec 2020 02:46:11 +0000 X-MC-Relay: Neutral X-MailChannels-SenderId: dreamhost|x-authsender|siddhesh@gotplt.org X-MailChannels-Auth-Id: dreamhost X-Vacuous-Quick: 39df4a697850332d_1608777970922_1256338346 X-MC-Loop-Signature: 1608777970922:3128437610 X-MC-Ingress-Time: 1608777970922 Received: from pdx1-sub0-mail-a69.g.dreamhost.com (localhost [127.0.0.1]) by pdx1-sub0-mail-a69.g.dreamhost.com (Postfix) with ESMTP id 1EB5788576; Wed, 23 Dec 2020 18:46:09 -0800 (PST) Received: from rhbox.intra.reserved-bit.com (unknown [1.186.101.110]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: siddhesh@gotplt.org) by pdx1-sub0-mail-a69.g.dreamhost.com (Postfix) with ESMTPSA id 9CADB88573; Wed, 23 Dec 2020 18:46:06 -0800 (PST) X-DH-BACKEND: pdx1-sub0-mail-a69 To: libc-alpha@sourceware.org Subject: [PATCH v3 1/2] x86 long double: Consider pseudo numbers as signaling Date: Thu, 24 Dec 2020 08:15:53 +0530 Message-Id: <20201224024554.3579622-2-siddhesh@sourceware.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201224024554.3579622-1-siddhesh@sourceware.org> References: <20201224024554.3579622-1-siddhesh@sourceware.org> MIME-Version: 1.0 X-Spam-Status: No, score=-9.0 required=5.0 tests=BAYES_00, GIT_PATCH_0, JMQ_SPF_NEUTRAL, KAM_DMARC_NONE, KAM_DMARC_STATUS, KAM_SHORT, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_NEUTRAL, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Siddhesh Poyarekar via Libc-alpha From: Siddhesh Poyarekar Reply-To: Siddhesh Poyarekar Cc: fweimer@redhat.com, joseph@codesourcery.com Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" Add support to treat pseudo-numbers specially and implement x86 version to consider all of them as signaling. Reviewed-by: Adhemerval Zanella --- sysdeps/generic/nan-pseudo-number.h | 32 ++++++++++++++++++++++++ sysdeps/ieee754/ldbl-96/s_issignalingl.c | 11 +++++--- sysdeps/x86/fpu/nan-pseudo-number.h | 30 ++++++++++++++++++++++ 3 files changed, 70 insertions(+), 3 deletions(-) create mode 100644 sysdeps/generic/nan-pseudo-number.h create mode 100644 sysdeps/x86/fpu/nan-pseudo-number.h diff --git a/sysdeps/generic/nan-pseudo-number.h b/sysdeps/generic/nan-pseudo-number.h new file mode 100644 index 0000000000..1562e06e4b --- /dev/null +++ b/sysdeps/generic/nan-pseudo-number.h @@ -0,0 +1,32 @@ +/* Pseudo-normal number handling. Generic version. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef NAN_PSEUDO_NUMBER_H +#define NAN_PSEUDO_NUMBER_H 1 + +/* Set this macro and override the definition of IS_PSEUDO_SIGNALING if pseudo + numbers need special handling. */ +#define HANDLE_PSEUDO_NUMBERS 0 +static inline int +is_pseudo_signaling (uint32_t exi __attribute__ ((unused)), + uint32_t hxi __attribute__ ((unused))) +{ + return 0; +} + +#endif /* nan-pseudo-number.h */ diff --git a/sysdeps/ieee754/ldbl-96/s_issignalingl.c b/sysdeps/ieee754/ldbl-96/s_issignalingl.c index ec542ad468..37e05aa259 100644 --- a/sysdeps/ieee754/ldbl-96/s_issignalingl.c +++ b/sysdeps/ieee754/ldbl-96/s_issignalingl.c @@ -19,12 +19,19 @@ #include #include #include +#include int __issignalingl (long double x) { uint32_t exi, hxi, lxi; GET_LDOUBLE_WORDS (exi, hxi, lxi, x); + + /* By default we do not recognize a pseudo NaN as sNaN. However on 80387 and + later all pseudo numbers including pseudo NaNs result in a signal and are + hence recognized as signaling. */ + int ret = is_pseudo_signaling (exi, hxi); + #if HIGH_ORDER_BIT_IS_SET_FOR_SNAN # error not implemented #else @@ -34,11 +41,9 @@ __issignalingl (long double x) hxi ^= 0x40000000; /* If lxi != 0, then set any suitable bit of the significand in hxi. */ hxi |= (lxi | -lxi) >> 31; - /* We do not recognize a pseudo NaN as sNaN; they're invalid on 80387 and - later. */ /* We have to compare for greater (instead of greater or equal), because x's significand being all-zero designates infinity not NaN. */ - return ((exi & 0x7fff) == 0x7fff) && (hxi > 0xc0000000); + return ret || (((exi & 0x7fff) == 0x7fff) && (hxi > 0xc0000000)); #endif } libm_hidden_def (__issignalingl) diff --git a/sysdeps/x86/fpu/nan-pseudo-number.h b/sysdeps/x86/fpu/nan-pseudo-number.h new file mode 100644 index 0000000000..ea43b175a1 --- /dev/null +++ b/sysdeps/x86/fpu/nan-pseudo-number.h @@ -0,0 +1,30 @@ +/* Pseudo-normal number handling. x86 version. + Copyright (C) 2020 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef NAN_PSEUDO_NUMBER_H +#define NAN_PSEUDO_NUMBER_H 1 + +#define HANDLE_PSEUDO_NUMBERS 1 +/* Pseudo numbers on x86 are always signaling. */ +static inline int +is_pseudo_signaling (uint32_t exi, uint32_t hxi) +{ + return ((exi & 0x7fff) && ((hxi & 0x80000000) == 0)); +} + +#endif /* nan-pseudo-number.h */