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Violators will be prosecuted; Thu, 28 Jul 2016 16:49:56 +1000 X-IBM-Helo: d23dlp02.au.ibm.com X-IBM-MailFrom: nikunj@linux.vnet.ibm.com X-IBM-RcptTo: qemu-devel@nongnu.org;qemu-ppc@nongnu.org Received: from d23relay06.au.ibm.com (d23relay06.au.ibm.com [9.185.63.219]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 0AC272BB0045; Thu, 28 Jul 2016 16:49:56 +1000 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay06.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u6S6nuTN31195144; Thu, 28 Jul 2016 16:49:56 +1000 Received: from d23av04.au.ibm.com (localhost [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u6S6ntvM009090; Thu, 28 Jul 2016 16:49:55 +1000 Received: from abhimanyu.in.ibm.com (abhimanyu.in.ibm.com [9.124.35.55]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u6S6npOW008811; Thu, 28 Jul 2016 16:49:53 +1000 From: Nikunj A Dadhania To: qemu-ppc@nongnu.org, david@gibson.dropbear.id.au, rth@twiddle.net Date: Thu, 28 Jul 2016 12:19:34 +0530 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1469688581-30853-1-git-send-email-nikunj@linux.vnet.ibm.com> References: <1469688581-30853-1-git-send-email-nikunj@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16072806-0008-0000-0000-000000AA2120 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16072806-0009-0000-0000-000007BCA037 Message-Id: <1469688581-30853-2-git-send-email-nikunj@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-07-28_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1607280071 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.158.5 Subject: [Qemu-devel] [PATCH v1 1/8] target-ppc: implement branch-less divw[o][.] 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: aneesh.kumar@linux.vnet.ibm.com, qemu-devel@nongnu.org, nikunj@linux.vnet.ibm.com, bharata@linux.vnet.ibm.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP While implementing modulo instructions figured out that the implementation uses many branches. Change the logic to achieve the branch-less code. Undefined value is set to dividend in case of invalid input. Signed-off-by: Nikunj A Dadhania Reviewed-by: Richard Henderson --- target-ppc/translate.c | 48 +++++++++++++++++++++++------------------------- 1 file changed, 23 insertions(+), 25 deletions(-) diff --git a/target-ppc/translate.c b/target-ppc/translate.c index 3dd9a48..2a5ce3f 100644 --- a/target-ppc/translate.c +++ b/target-ppc/translate.c @@ -1096,41 +1096,39 @@ static void gen_addpcis(DisasContext *ctx) static inline void gen_op_arith_divw(DisasContext *ctx, TCGv ret, TCGv arg1, TCGv arg2, int sign, int compute_ov) { - TCGLabel *l1 = gen_new_label(); - TCGLabel *l2 = gen_new_label(); - TCGv_i32 t0 = tcg_temp_local_new_i32(); - TCGv_i32 t1 = tcg_temp_local_new_i32(); + TCGv_i32 t0 = tcg_temp_new_i32(); + TCGv_i32 t1 = tcg_temp_new_i32(); + TCGv_i32 t2 = tcg_temp_new_i32(); + TCGv_i32 t3 = tcg_temp_new_i32(); tcg_gen_trunc_tl_i32(t0, arg1); tcg_gen_trunc_tl_i32(t1, arg2); - tcg_gen_brcondi_i32(TCG_COND_EQ, t1, 0, l1); - if (sign) { - TCGLabel *l3 = gen_new_label(); - tcg_gen_brcondi_i32(TCG_COND_NE, t1, -1, l3); - tcg_gen_brcondi_i32(TCG_COND_EQ, t0, INT32_MIN, l1); - gen_set_label(l3); - tcg_gen_div_i32(t0, t0, t1); - } else { - tcg_gen_divu_i32(t0, t0, t1); - } - if (compute_ov) { - tcg_gen_movi_tl(cpu_ov, 0); - } - tcg_gen_br(l2); - gen_set_label(l1); if (sign) { - tcg_gen_sari_i32(t0, t0, 31); + tcg_gen_setcondi_i32(TCG_COND_EQ, t2, t0, INT_MIN); + tcg_gen_setcondi_i32(TCG_COND_EQ, t3, t1, -1); + tcg_gen_and_i32(t2, t2, t3); + tcg_gen_setcondi_i32(TCG_COND_EQ, t3, t1, 0); + tcg_gen_or_i32(t2, t2, t3); + tcg_gen_movi_i32(t3, 0); + tcg_gen_movcond_i32(TCG_COND_NE, t1, t2, t3, t2, t1); + tcg_gen_div_i32(t3, t0, t1); + tcg_gen_extu_i32_tl(ret, t3); } else { - tcg_gen_movi_i32(t0, 0); + tcg_gen_setcondi_i32(TCG_COND_EQ, t2, t1, 0); + tcg_gen_movi_i32(t3, 0); + tcg_gen_movcond_i32(TCG_COND_NE, t1, t2, t3, t2, t1); + tcg_gen_divu_i32(t3, t0, t1); + tcg_gen_extu_i32_tl(ret, t3); } if (compute_ov) { - tcg_gen_movi_tl(cpu_ov, 1); - tcg_gen_movi_tl(cpu_so, 1); + tcg_gen_extu_i32_tl(cpu_ov, t2); + tcg_gen_or_tl(cpu_so, cpu_so, cpu_ov); } - gen_set_label(l2); - tcg_gen_extu_i32_tl(ret, t0); tcg_temp_free_i32(t0); tcg_temp_free_i32(t1); + tcg_temp_free_i32(t2); + tcg_temp_free_i32(t3); + if (unlikely(Rc(ctx->opcode) != 0)) gen_set_Rc0(ctx, ret); }