From mboxrd@z Thu Jan 1 00:00:00 1970 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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no 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 55279C43331 for ; Sat, 28 Mar 2020 15:18:53 +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 256AA20716 for ; Sat, 28 Mar 2020 15:18:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 256AA20716 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-sky.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53944 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jIDEa-00059c-CE for qemu-devel@archiver.kernel.org; Sat, 28 Mar 2020 11:18:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38853) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jIDDL-0004YA-Jg for qemu-devel@nongnu.org; Sat, 28 Mar 2020 11:17:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jIDDK-00043F-A0 for qemu-devel@nongnu.org; Sat, 28 Mar 2020 11:17:35 -0400 Received: from smtp2200-217.mail.aliyun.com ([121.197.200.217]:52750) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jIDDJ-0003ga-Ox; Sat, 28 Mar 2020 11:17:34 -0400 X-Alimail-AntiSpam: AC=CONTINUE; BC=0.1948451|-1; CH=green; DM=|CONTINUE|false|; DS=CONTINUE|ham_regular_dialog|0.249244-0.000384504-0.750372; FP=0|0|0|0|0|-1|-1|-1; HT=e01a16370; MF=zhiwei_liu@c-sky.com; NM=1; PH=DS; RN=9; RT=9; SR=0; TI=SMTPD_---.H6itAyb_1585408632; Received: from 192.168.3.18(mailfrom:zhiwei_liu@c-sky.com fp:SMTPD_---.H6itAyb_1585408632) by smtp.aliyun-inc.com(10.147.41.178); Sat, 28 Mar 2020 23:17:14 +0800 Subject: Re: [PATCH v6 18/61] target/riscv: vector single-width integer multiply instructions To: Richard Henderson , alistair23@gmail.com, chihmin.chao@sifive.com, palmer@dabbelt.com References: <20200317150653.9008-1-zhiwei_liu@c-sky.com> <20200317150653.9008-19-zhiwei_liu@c-sky.com> <1a5900d9-dc26-04f2-74b2-0bada246a0e7@linaro.org> From: LIU Zhiwei Message-ID: <8be612c0-4345-c1f2-3b82-73a9a1ea4133@c-sky.com> Date: Sat, 28 Mar 2020 23:17:11 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <1a5900d9-dc26-04f2-74b2-0bada246a0e7@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 121.197.200.217 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: guoren@linux.alibaba.com, wenmeng_zhang@c-sky.com, qemu-riscv@nongnu.org, qemu-devel@nongnu.org, wxy194768@alibaba-inc.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2020/3/28 8:06, Richard Henderson wrote: > On 3/17/20 8:06 AM, LIU Zhiwei wrote: >> +static int64_t do_mulhsu_d(int64_t s2, uint64_t s1) >> +{ >> + uint64_t hi_64, lo_64, abs_s2 = s2; >> + >> + if (s2 < 0) { >> + abs_s2 = -s2; >> + } >> + mulu64(&lo_64, &hi_64, abs_s2, s1); >> + if (s2 < 0) { >> + lo_64 = ~lo_64; >> + hi_64 = ~hi_64; >> + if (lo_64 == UINT64_MAX) { >> + lo_64 = 0; >> + hi_64 += 1; >> + } else { >> + lo_64 += 1; >> + } >> + } >> + >> + return hi_64; >> +} > Missed the improvement here. See tcg_gen_mulsu2_i64. Though I have not gotten the principle, the code in tcg_gen_mulsu2_i64 is much tidier. Thanks for pointing that. Zhiwei > Otherwise, > Reviewed-by: Richard Henderson > > > r~