From nobody Wed Nov 5 14:32:19 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; dkim=fail; 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 Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1534826585631317.73087505096987; Mon, 20 Aug 2018 21:43:05 -0700 (PDT) Received: from localhost ([::1]:50685 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fryVP-0003mL-UJ for importer@patchew.org; Tue, 21 Aug 2018 00:43:00 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56505) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fryMt-0004Bj-P0 for qemu-devel@nongnu.org; Tue, 21 Aug 2018 00:34:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fryMo-0000Mg-WD for qemu-devel@nongnu.org; Tue, 21 Aug 2018 00:34:09 -0400 Received: from ozlabs.org ([2401:3900:2:1::2]:39495) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fryMk-0000EZ-NT; Tue, 21 Aug 2018 00:34:05 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 41vd9D3FRcz9s8T; Tue, 21 Aug 2018 14:33:51 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1534826032; bh=G3e+S+2w+W6fKwuLScOLzB6nQqulR8QVBOydqj85YAw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m0r4mfkA800pRp4hzDPou9UjSvvZIODawSQ61bnEUI+UTJJrNV4h0LRZnMLB+/NGr UTm4sIlkMouLX9M8CyNf0Y8ajx0Zqbyf42ttRML/7x6WRe6yd+ltafrZWapyeGQPe4 GQFaX0H1FrrRIOsEkQ4bYr9zLA2F9WbaxwgUGtGY= From: David Gibson To: peter.maydell@linaro.org Date: Tue, 21 Aug 2018 14:33:30 +1000 Message-Id: <20180821043343.7514-14-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180821043343.7514-1-david@gibson.dropbear.id.au> References: <20180821043343.7514-1-david@gibson.dropbear.id.au> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2401:3900:2:1::2 Subject: [Qemu-devel] [PULL 13/26] 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: lvivier@redhat.com, aik@ozlabs.ru, groug@kaod.org, qemu-devel@nongnu.org, Yasmin Beatriz , qemu-ppc@nongnu.org, clg@kaod.org, David Gibson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZohoMail: RDKM_2 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Yasmin Beatriz 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 Signed-off-by: David Gibson --- 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 ac7f92d7ae..fcac90a4a9 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 2.17.1