From nobody Wed Nov 5 02:32:13 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=linux.ibm.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1532971744712500.4886526806532; Mon, 30 Jul 2018 10:29:04 -0700 (PDT) Received: from localhost ([::1]:54030 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fkByh-0005kz-HM for importer@patchew.org; Mon, 30 Jul 2018 13:29:03 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49449) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fkBfk-0006KL-62 for qemu-devel@nongnu.org; Mon, 30 Jul 2018 13:09:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fkBfh-0003SV-Ar for qemu-devel@nongnu.org; Mon, 30 Jul 2018 13:09:28 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:51660) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fkBfh-0003Rl-0z for qemu-devel@nongnu.org; Mon, 30 Jul 2018 13:09:25 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w6UH8lPP021025 for ; Mon, 30 Jul 2018 13:09:22 -0400 Received: from e35.co.us.ibm.com (e35.co.us.ibm.com [32.97.110.153]) by mx0a-001b2d01.pphosted.com with ESMTP id 2kj5sv300e-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 30 Jul 2018 13:09:22 -0400 Received: from localhost by e35.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 30 Jul 2018 11:09:19 -0600 Received: from b03ledav002.gho.boulder.ibm.com (b03ledav002.gho.boulder.ibm.com [9.17.130.233]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w6UH9I467733756 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 30 Jul 2018 10:09:18 -0700 Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8D428136060; Mon, 30 Jul 2018 11:09:18 -0600 (MDT) Received: from b03ledav002.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3D407136055; Mon, 30 Jul 2018 11:09:18 -0600 (MDT) Received: from yasmins-centos-7-ppc64le.aus.stglabs.ibm.com (unknown [9.40.192.146]) by b03ledav002.gho.boulder.ibm.com (Postfix) with ESMTP; Mon, 30 Jul 2018 11:09:18 -0600 (MDT) From: Yasmin Beatriz To: qemu-ppc@nongnu.org Date: Mon, 30 Jul 2018 17:09:17 +0000 X-Mailer: git-send-email 1.8.3.1 X-TM-AS-GCONF: 00 x-cbid: 18073017-0012-0000-0000-000016939E11 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009458; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01068146; UDB=6.00549071; IPR=6.00846249; MB=3.00022408; MTD=3.00000008; XFM=3.00000015; UTC=2018-07-30 17:09:21 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18073017-0013-0000-0000-000053DB2CF8 Message-Id: <1532970557-22894-1-git-send-email-yasmins@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-07-30_08:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=874 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807300186 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH v2] target/ppc: simplify bcdadd/sub functions X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: rth@twiddle.net, qemu-devel@nongnu.org, david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" After solving a corner case in bcdsub, this patch simplifies the logic of both bcdadd/sub instructions by removing some unnecessary local flags. This commit also rearranges some if-else conditions in bcdadd to make it easier to read. Signed-off-by: Yasmin Beatriz --- target/ppc/int_helper.c | 49 ++++++++++++++++++---------------------------= ---- 1 file changed, 18 insertions(+), 31 deletions(-) diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c index fa18e6e..1906f22 100644 --- a/target/ppc/int_helper.c +++ b/target/ppc/int_helper.c @@ -2671,16 +2671,14 @@ static int bcd_cmp_mag(ppc_avr_t *a, ppc_avr_t *b) return 0; } =20 -static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *inva= lid, +static void bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *inv= alid, int *overflow) { int carry =3D 0; int i; - int is_zero =3D 1; for (i =3D 1; i <=3D 31; i++) { uint8_t digit =3D bcd_get_digit(a, i, invalid) + bcd_get_digit(b, i, invalid) + carry; - is_zero &=3D (digit =3D=3D 0); if (digit > 9) { carry =3D 1; digit -=3D 10; @@ -2689,26 +2687,20 @@ static int bcd_add_mag(ppc_avr_t *t, ppc_avr_t *a, = ppc_avr_t *b, int *invalid, } =20 bcd_put_digit(t, digit, i); - - if (unlikely(*invalid)) { - return -1; - } } =20 *overflow =3D carry; - return is_zero; } =20 -static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *inva= lid, +static void bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, ppc_avr_t *b, int *inv= alid, int *overflow) { int carry =3D 0; int i; - int is_zero =3D 1; + for (i =3D 1; i <=3D 31; i++) { uint8_t digit =3D bcd_get_digit(a, i, invalid) - bcd_get_digit(b, i, invalid) + carry; - is_zero &=3D (digit =3D=3D 0); if (digit & 0x80) { carry =3D -1; digit +=3D 10; @@ -2717,14 +2709,9 @@ static int bcd_sub_mag(ppc_avr_t *t, ppc_avr_t *a, p= pc_avr_t *b, int *invalid, } =20 bcd_put_digit(t, digit, i); - - if (unlikely(*invalid)) { - return -1; - } } =20 *overflow =3D carry; - return is_zero; } =20 uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, ppc_avr_t *b, uint32_t= ps) @@ -2734,26 +2721,28 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a,= ppc_avr_t *b, uint32_t ps) int sgnb =3D bcd_get_sgn(b); int invalid =3D (sgna =3D=3D 0) || (sgnb =3D=3D 0); int overflow =3D 0; - int zero =3D 0; uint32_t cr =3D 0; ppc_avr_t result =3D { .u64 =3D { 0, 0 } }; =20 if (!invalid) { if (sgna =3D=3D sgnb) { result.u8[BCD_DIG_BYTE(0)] =3D bcd_preferred_sgn(sgna, ps); - zero =3D bcd_add_mag(&result, a, b, &invalid, &overflow); - cr =3D (sgna > 0) ? CRF_GT : CRF_LT; - } else if (bcd_cmp_mag(a, b) > 0) { - result.u8[BCD_DIG_BYTE(0)] =3D bcd_preferred_sgn(sgna, ps); - zero =3D bcd_sub_mag(&result, a, b, &invalid, &overflow); - cr =3D (sgna > 0) ? CRF_GT : CRF_LT; - } else if (bcd_cmp_mag(a, b) =3D=3D 0) { - result.u8[BCD_DIG_BYTE(0)] =3D bcd_preferred_sgn(0, ps); - zero =3D bcd_sub_mag(&result, b, a, &invalid, &overflow); + bcd_add_mag(&result, a, b, &invalid, &overflow); + cr =3D bcd_cmp_zero(&result); } else { - result.u8[BCD_DIG_BYTE(0)] =3D bcd_preferred_sgn(sgnb, ps); - zero =3D bcd_sub_mag(&result, b, a, &invalid, &overflow); - cr =3D (sgnb > 0) ? CRF_GT : CRF_LT; + int magnitude =3D bcd_cmp_mag(a, b); + if (magnitude > 0) { + result.u8[BCD_DIG_BYTE(0)] =3D bcd_preferred_sgn(sgna, ps); + bcd_sub_mag(&result, a, b, &invalid, &overflow); + cr =3D (sgna > 0) ? CRF_GT : CRF_LT; + } else if (magnitude < 0) { + result.u8[BCD_DIG_BYTE(0)] =3D bcd_preferred_sgn(sgnb, ps); + bcd_sub_mag(&result, b, a, &invalid, &overflow); + cr =3D (sgnb > 0) ? CRF_GT : CRF_LT; + } else { + result.u8[BCD_DIG_BYTE(0)] =3D bcd_preferred_sgn(0, ps); + cr =3D CRF_EQ; + } } } =20 @@ -2762,8 +2751,6 @@ uint32_t helper_bcdadd(ppc_avr_t *r, ppc_avr_t *a, p= pc_avr_t *b, uint32_t ps) cr =3D CRF_SO; } else if (overflow) { cr |=3D CRF_SO; - } else if (zero) { - cr =3D CRF_EQ; } =20 *r =3D result; --=20 1.8.3.1