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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 54EB1C4338F for ; Tue, 24 Aug 2021 14:40:42 +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 C35766135F for ; Tue, 24 Aug 2021 14:40:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C35766135F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=eldorado.org.br Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:41070 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mIXbU-00039M-UR for qemu-devel@archiver.kernel.org; Tue, 24 Aug 2021 10:40:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54694) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mIXPi-0007Vc-81; Tue, 24 Aug 2021 10:28:30 -0400 Received: from [201.28.113.2] (port=1602 helo=outlook.eldorado.org.br) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mIXPg-0007tk-RP; Tue, 24 Aug 2021 10:28:30 -0400 Received: from power9a ([10.10.71.235]) by outlook.eldorado.org.br with Microsoft SMTPSVC(8.5.9600.16384); Tue, 24 Aug 2021 11:28:09 -0300 Received: from eldorado.org.br (unknown [10.10.70.45]) by power9a (Postfix) with ESMTP id 1329B8010FC; Tue, 24 Aug 2021 11:28:09 -0300 (-03) From: Luis Pires To: qemu-devel@nongnu.org, qemu-ppc@nongnu.org Subject: [PATCH 10/19] host-utils: Introduce mulu128 Date: Tue, 24 Aug 2021 11:27:21 -0300 Message-Id: <20210824142730.102421-11-luis.pires@eldorado.org.br> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210824142730.102421-1-luis.pires@eldorado.org.br> References: <20210824142730.102421-1-luis.pires@eldorado.org.br> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-OriginalArrivalTime: 24 Aug 2021 14:28:09.0277 (UTC) FILETIME=[42E9A6D0:01D798F4] X-Host-Lookup-Failed: Reverse DNS lookup failed for 201.28.113.2 (failed) Received-SPF: pass client-ip=201.28.113.2; envelope-from=luis.pires@eldorado.org.br; helo=outlook.eldorado.org.br X-Spam_score_int: -10 X-Spam_score: -1.1 X-Spam_bar: - X-Spam_report: (-1.1 / 5.0 requ) BAYES_00=-1.9, PDS_HP_HELO_NORDNS=0.001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action 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: Luis Pires , richard.henderson@linaro.org, groug@kaod.org, david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: Luis Pires --- include/qemu/host-utils.h | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h index 8e8cab9a3e..2e3b5ad989 100644 --- a/include/qemu/host-utils.h +++ b/include/qemu/host-utils.h @@ -588,6 +588,44 @@ static inline bool umul64_overflow(uint64_t x, uint64_t y, uint64_t *ret) #endif } +/* + * Unsigned 128x64 multiplication. + * Returns true if the result got truncated to 128 bits. + * Otherwise, returns false and the multiplication result via plow and phigh. + */ +static inline bool mulu128(uint64_t *plow, uint64_t *phigh, uint64_t factor) +{ +#if defined(CONFIG_INT128) && \ + (__has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5) + bool res; + __uint128_t r; + __uint128_t f = ((__uint128_t)*phigh << 64) | *plow; + res = __builtin_mul_overflow(f, factor, &r); + + *plow = r; + *phigh = r >> 64; + + return res; +#else + uint64_t dhi = *phigh; + uint64_t dlo = *plow; + uint64_t ahi; + uint64_t blo, bhi; + + if (dhi == 0) { + mulu64(plow, phigh, dlo, factor); + return false; + } + + mulu64(plow, &ahi, dlo, factor); + mulu64(&blo, &bhi, dhi, factor); + + *phigh = ahi + blo; + + return (bhi > 0) || (*phigh < ahi); +#endif +} + /** * uadd64_carry - addition with carry-in and carry-out * @x, @y: addends -- 2.25.1