From patchwork Wed Jun 24 10:50:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 279574 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=DKIM_INVALID,DKIM_SIGNED, 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 7137DC433E0 for ; Wed, 24 Jun 2020 11:07:07 +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 3D6942082F for ; Wed, 24 Jun 2020 11:07:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gI4KIqXD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3D6942082F 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]:59072 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jo3FC-0006cA-Fn for qemu-devel@archiver.kernel.org; Wed, 24 Jun 2020 07:07:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56690) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jo2zr-0001Js-ME for qemu-devel@nongnu.org; Wed, 24 Jun 2020 06:51:15 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:46527 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 1jo2zo-0001M7-II for qemu-devel@nongnu.org; Wed, 24 Jun 2020 06:51:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592995871; 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=p+e44PK7Fg88toihiGf2bKkm4Ptn4UtPgBDIsEqYnl0=; b=gI4KIqXDxqM6EhPdKeGCGuTpFfupg9HP64n2KXYWO984vnj+j0Mu7bS3mmkD7itajnvbky G53c/bohF0VIazp/t0NVvdYEnv+FcyRQRoHapUIYSlhzUnMR2Shb9IvNFHBCFCGyrwlBWH SKX8GtMpTfR6IENgBz2ANW3qe9g6Y+Q= 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-181-WhIw6673MHytzpkXEGEeLg-1; Wed, 24 Jun 2020 06:51:09 -0400 X-MC-Unique: WhIw6673MHytzpkXEGEeLg-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 7C142107ACCA; Wed, 24 Jun 2020 10:51:08 +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 0E7DD5D9C5; Wed, 24 Jun 2020 10:51:07 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 19/31] softfloat: return low bits of quotient from floatx80_modrem Date: Wed, 24 Jun 2020 06:50:36 -0400 Message-Id: <20200624105048.375353-19-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=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 = 2020/06/24 02:33:25 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Joseph Myers 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 Reviewed-by: Richard Henderson Message-Id: Signed-off-by: Paolo Bonzini --- 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 1ee3342715..79be4f5840 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -5699,10 +5699,11 @@ 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; @@ -5710,6 +5711,7 @@ 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); @@ -5768,7 +5770,7 @@ 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 ) { @@ -5778,6 +5780,8 @@ 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 ) { @@ -5791,6 +5795,12 @@ 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; @@ -5805,6 +5815,7 @@ floatx80 floatx80_modrem(floatx80 a, floatx80 b, bool mod, aSig0 = alternateASig0; aSig1 = alternateASig1; zSign = ! zSign; + ++*quotient; } } return @@ -5821,7 +5832,8 @@ 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); } /*---------------------------------------------------------------------------- @@ -5832,7 +5844,8 @@ 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);