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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 34F5BCA0FE1 for ; Fri, 1 Sep 2023 11:51:38 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qc2gM-0000yQ-Qe; Fri, 01 Sep 2023 07:51:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qc2gL-0000cn-3Q; Fri, 01 Sep 2023 07:51:21 -0400 Received: from gandalf.ozlabs.org ([150.107.74.76]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qc2gI-0008Ed-JO; Fri, 01 Sep 2023 07:51:20 -0400 Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4Rcbw05XPwz4wb5; Fri, 1 Sep 2023 21:51:12 +1000 (AEST) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4Rcbvx0mv5z4wZw; Fri, 1 Sep 2023 21:51:08 +1000 (AEST) Message-ID: Date: Fri, 1 Sep 2023 13:51:05 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH v2 05/19] host-utils: Add muldiv64_round_up Content-Language: en-US To: Nicholas Piggin , Daniel Henrique Barboza Cc: David Gibson , Greg Kurz , Harsh Prateek Bora , Pavel Dovgalyuk , Paolo Bonzini , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Peter Maydell , =?UTF-8?Q?Daniel_P=2e_Berrang=c3=a9?= References: <20230808042001.411094-1-npiggin@gmail.com> <20230808042001.411094-6-npiggin@gmail.com> From: =?UTF-8?Q?C=c3=a9dric_Le_Goater?= In-Reply-To: <20230808042001.411094-6-npiggin@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=150.107.74.76; envelope-from=SRS0=SnXb=ER=kaod.org=clg@ozlabs.org; helo=gandalf.ozlabs.org X-Spam_score_int: -50 X-Spam_score: -5.1 X-Spam_bar: ----- X-Spam_report: (-5.1 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, NICE_REPLY_A=-3.478, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Adding more reviewers since this patch is modifying a common service. Thanks, C. On 8/8/23 06:19, Nicholas Piggin wrote: > This will be used for converting time intervals in different base units > to host units, for the purpose of scheduling timers to emulate target > timers. Timers typically must not fire before their requested expiry > time but may fire some time afterward, so rounding up is the right way > to implement these. > > Signed-off-by: Nicholas Piggin > --- > include/qemu/host-utils.h | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > > diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h > index 011618373e..e2a50a567f 100644 > --- a/include/qemu/host-utils.h > +++ b/include/qemu/host-utils.h > @@ -56,6 +56,11 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) > return (__int128_t)a * b / c; > } > > +static inline uint64_t muldiv64_round_up(uint64_t a, uint32_t b, uint32_t c) > +{ > + return ((__int128_t)a * b + c - 1) / c; > +} > + > static inline uint64_t divu128(uint64_t *plow, uint64_t *phigh, > uint64_t divisor) > { > @@ -83,7 +88,8 @@ void mulu64(uint64_t *plow, uint64_t *phigh, uint64_t a, uint64_t b); > uint64_t divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor); > int64_t divs128(uint64_t *plow, int64_t *phigh, int64_t divisor); > > -static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) > +static inline uint64_t __muldiv64(uint64_t a, uint32_t b, uint32_t c, > + bool round_up) > { > union { > uint64_t ll; > @@ -99,12 +105,25 @@ static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) > > u.ll = a; > rl = (uint64_t)u.l.low * (uint64_t)b; > + if (round_up) { > + rl += c - 1; > + } > rh = (uint64_t)u.l.high * (uint64_t)b; > rh += (rl >> 32); > res.l.high = rh / c; > res.l.low = (((rh % c) << 32) + (rl & 0xffffffff)) / c; > return res.ll; > } > + > +static inline uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c) > +{ > + return __muldiv64(a, b, c, false); > +} > + > +static inline uint64_t muldiv64_round_up(uint64_t a, uint32_t b, uint32_t c) > +{ > + return __muldiv64(a, b, c, true); > +} > #endif > > /**