From patchwork Fri Jun 5 19:01:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joseph Myers X-Patchwork-Id: 281239 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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_SANE_1 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 715B7C433E0 for ; Fri, 5 Jun 2020 19:04:33 +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 09D682077D for ; Fri, 5 Jun 2020 19:04:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 09D682077D 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]:54758 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jhHdo-0004Lz-22 for qemu-devel@archiver.kernel.org; Fri, 05 Jun 2020 15:04:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58458) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jhHbH-00019D-E8 for qemu-devel@nongnu.org; Fri, 05 Jun 2020 15:01:55 -0400 Received: from esa2.mentor.iphmx.com ([68.232.141.98]:23580) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jhHbG-00076X-63 for qemu-devel@nongnu.org; Fri, 05 Jun 2020 15:01:54 -0400 IronPort-SDR: GESuwUlyosFx7RetCaBg7rzrfteYNguZE7SsASwaltADL/OLqJ8DyzdtgdqzMLBJ1Jnx50e+uf fYPMOrDWKfPZAbBBYWlSoomB3Y3ZJleHWXAMwEtC2/oBsBw0+tQTIfY/LvUnwstYXtW5JgblOH sSYwmPCu1yZKHgNWjkdid5wLit7nMMxk3NVYUztIOvyF/7A68rnJ0E1MTBQHIewxFsrqnuBetW /LHTvqcYVPfQXvUGIGw9HK+ByfGSeXPRNX3hdJvydHfpL6gU3Hx4ZNN2fHeHGZzbIJo1vRUhcU Hws= X-IronPort-AV: E=Sophos;i="5.73,477,1583222400"; d="scan'208";a="49520928" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa2.mentor.iphmx.com with ESMTP; 05 Jun 2020 11:01:52 -0800 IronPort-SDR: 0MqKEzmhVaRvFZrDZgkWBBV3SjyS1fZKaR7r85cI6dXFqt6lo92ZKt90CA7Qtsl96Br6VOGtFH X942gZLfkhce5SfNdlV/60t4tgu60xCD8P/CzHRssfy1bnouNkuvYjJza8e6Pwf0GjY7fcaR+Q SmiUwgOaQqcIjbjjV5U7NNxyhuEsI5R+dLDhBVshB0aC27X0k81PNi9i+Y0YR8wI9bnYy0wolz rEXbeK2lg2oidusI/tdKmWH+xYJVLIE3BwM4EGO4NKfgHVe7O5aPBx5t6Ao3G2pADPfgRmIV8g woM= Date: Fri, 5 Jun 2020 19:01:46 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: , , , , , , , Subject: [PATCH 5/7] softfloat: return low bits of quotient from floatx80_modrem In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: svr-ies-mbx-02.mgc.mentorg.com (139.181.222.2) To svr-ies-mbx-02.mgc.mentorg.com (139.181.222.2) Received-SPF: pass client-ip=68.232.141.98; envelope-from=joseph_myers@mentor.com; helo=esa2.mentor.iphmx.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/05 14:58:48 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_HELO_PASS=-0.001, 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Both x87 and m68k need the low parts of the quotient for their remainder operations. Arrange for floatx80_modrem to track those bits and return them via a pointer. The architectures using float32_rem and float64_rem do not appear to need this information, so the *_rem interface is left unchanged and the information returned only from floatx80_modrem. The logic used to determine the low 7 bits of the quotient for m68k (target/m68k/fpu_helper.c:make_quotient) appears completely bogus (it looks at the result of converting the remainder to integer, the quotient having been discarded by that point); this patch does not change that, but the m68k maintainers may wish to do so. Signed-off-by: Joseph Myers --- fpu/softfloat.c | 23 ++++++++++++++++++----- include/fpu/softfloat.h | 3 ++- 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 423a815196..c3c3f382af 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -5684,10 +5684,11 @@ floatx80 floatx80_div(floatx80 a, floatx80 b, float_status *status) | `a' with respect to the corresponding value `b'. The operation is performed | according to the IEC/IEEE Standard for Binary Floating-Point Arithmetic, | if 'mod' is false; if 'mod' is true, return the remainder based on truncating -| the quotient toward zero instead. +| the quotient toward zero instead. '*quotient' is set to the low 64 bits of +| the absolute value of the integer quotient. *----------------------------------------------------------------------------*/ -floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, +floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, uint64_t *quotient, float_status *status) { bool aSign, zSign; @@ -5695,6 +5696,7 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, uint64_t aSig0, aSig1, bSig; uint64_t q, term0, term1, alternateASig0, alternateASig1; + *quotient = 0; if (floatx80_invalid_encoding(a) || floatx80_invalid_encoding(b)) { float_raise(float_flag_invalid, status); return floatx80_default_nan(status); @@ -5749,7 +5751,7 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, shift128Right( aSig0, 0, 1, &aSig0, &aSig1 ); expDiff = 0; } - q = ( bSig <= aSig0 ); + *quotient = q = ( bSig <= aSig0 ); if ( q ) aSig0 -= bSig; expDiff -= 64; while ( 0 < expDiff ) { @@ -5759,6 +5761,8 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, sub128( aSig0, aSig1, term0, term1, &aSig0, &aSig1 ); shortShift128Left( aSig0, aSig1, 62, &aSig0, &aSig1 ); expDiff -= 62; + *quotient <<= 62; + *quotient += q; } expDiff += 64; if ( 0 < expDiff ) { @@ -5772,6 +5776,12 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, ++q; sub128( aSig0, aSig1, term0, term1, &aSig0, &aSig1 ); } + if (expDiff < 64) { + *quotient <<= expDiff; + } else { + *quotient = 0; + } + *quotient += q; } else { term1 = 0; @@ -5786,6 +5796,7 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, aSig0 = alternateASig0; aSig1 = alternateASig1; zSign = ! zSign; + ++*quotient; } } return @@ -5802,7 +5813,8 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) { - return floatx80_modrem(a, b, false, status); + uint64_t quotient; + return floatx80_modrem(a, b, false, "ient, status); } /*---------------------------------------------------------------------------- @@ -5813,7 +5825,8 @@ floatx80 floatx80_rem(floatx80 a, floatx80 b, float_status *status) floatx80 floatx80_mod(floatx80 a, floatx80 b, float_status *status) { - return floatx80_modrem(a, b, true, status); + uint64_t quotient; + return floatx80_modrem(a, b, true, "ient, status); } /*---------------------------------------------------------------------------- diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index bff6934d09..ff4e2605b1 100644 --- a/include/fpu/softfloat.h +++ b/include/fpu/softfloat.h @@ -687,7 +687,8 @@ floatx80 floatx80_add(floatx80, floatx80, float_status *status); floatx80 floatx80_sub(floatx80, floatx80, float_status *status); floatx80 floatx80_mul(floatx80, floatx80, float_status *status); floatx80 floatx80_div(floatx80, floatx80, float_status *status); -floatx80 floatx80_modrem(floatx80, floatx80, bool, float_status *status); +floatx80 floatx80_modrem(floatx80, floatx80, bool, uint64_t *, + float_status *status); floatx80 floatx80_mod(floatx80, floatx80, float_status *status); floatx80 floatx80_rem(floatx80, floatx80, float_status *status); floatx80 floatx80_sqrt(floatx80, float_status *status);