From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by dpdk.org (Postfix) with ESMTP id A6F926904 for ; Tue, 11 Dec 2018 18:57:32 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Dec 2018 09:57:31 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,343,1539673200"; d="scan'208";a="282756745" Received: from irvmail001.ir.intel.com ([163.33.26.43]) by orsmga005.jf.intel.com with ESMTP; 11 Dec 2018 09:57:30 -0800 Received: from sivswdev05.ir.intel.com (sivswdev05.ir.intel.com [10.243.17.64]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id wBBHvTYX014324; Tue, 11 Dec 2018 17:57:29 GMT Received: from sivswdev05.ir.intel.com (localhost [127.0.0.1]) by sivswdev05.ir.intel.com with ESMTP id wBBHvTga024655; Tue, 11 Dec 2018 17:57:29 GMT Received: (from aburakov@localhost) by sivswdev05.ir.intel.com with LOCAL id wBBHvTmO024651; Tue, 11 Dec 2018 17:57:29 GMT From: Anatoly Burakov To: dev@dpdk.org Cc: thomas@monjalon.net, jasvinder.singh@intel.com, cristian.dumitrescu@intel.com, jerin.jacob@caviumnetworks.com Date: Tue, 11 Dec 2018 17:57:11 +0000 Message-Id: X-Mailer: git-send-email 1.7.0.7 In-Reply-To: <1cf22c82b6ca7561966be674afb8a02add0913b9.1544550999.git.anatoly.burakov@intel.com> References: <1cf22c82b6ca7561966be674afb8a02add0913b9.1544550999.git.anatoly.burakov@intel.com> In-Reply-To: <1cf22c82b6ca7561966be674afb8a02add0913b9.1544550999.git.anatoly.burakov@intel.com> References: <1cf22c82b6ca7561966be674afb8a02add0913b9.1544550999.git.anatoly.burakov@intel.com> Subject: [dpdk-dev] [PATCH 3/6] common: add missing implementations X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Dec 2018 17:57:33 -0000 Implement missing functions for 32-bit safe bsf, as well as 64-bit fls and log2. Signed-off-by: Anatoly Burakov --- Notes: v4: - Fixed to use proper rte_bsf64 v3: - Added clarification that pos is not checked lib/librte_eal/common/include/rte_common.h | 62 +++++++++++++++++++++- 1 file changed, 61 insertions(+), 1 deletion(-) diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h index 2735dcca7..4bbfef7a0 100644 --- a/lib/librte_eal/common/include/rte_common.h +++ b/lib/librte_eal/common/include/rte_common.h @@ -447,6 +447,30 @@ rte_bsf32(uint32_t v) return (uint32_t)__builtin_ctz(v); } +/** + * Searches the input parameter for the least significant set bit + * (starting from zero). Safe version (checks for input parameter being zero). + * + * @warning ``pos`` must be a valid pointer. It is not checked! + * + * @param v + * The input parameter. + * @param pos + * If ``v`` was not 0, this value will contain position of least significant + * bit within the input parameter. + * @return + * Returns 0 if ``v`` was 0, otherwise returns 1. + */ +static inline int +rte_bsf32_safe(uint64_t v, uint32_t *pos) +{ + if (v == 0) + return 0; + + *pos = rte_bsf32(v); + return 1; +} + /** * Return the rounded-up log2 of a integer. * @@ -464,7 +488,6 @@ rte_log2_u32(uint32_t v) return rte_bsf32(v); } - /** * Return the last (most-significant) bit set. * @@ -523,6 +546,43 @@ rte_bsf64_safe(uint64_t v, uint32_t *pos) return 1; } +/** + * Return the last (most-significant) bit set. + * + * @note The last (most significant) bit is at position 64. + * @note rte_fls_u64(0) = 0, rte_fls_u64(1) = 1, + * rte_fls_u64(0x8000000000000000) = 64 + * + * @param x + * The input parameter. + * @return + * The last (most-significant) bit set, or 0 if the input is 0. + */ +static inline int +rte_fls_u64(uint64_t x) +{ + return (x == 0) ? 0 : 64 - __builtin_clzll(x); +} + +/** + * Return the rounded-up log2 of a 64-bit integer. + * + * @param v + * The input parameter. + * @return + * The rounded-up log2 of the input, or 0 if the input is 0. + */ +static inline uint32_t +rte_log2_u64(uint64_t v) +{ + if (v == 0) + return 0; + v = rte_align64pow2(v); + /* we checked for v being 0 already, so no undefined behavior */ + return rte_bsf64(v); +} + + #ifndef offsetof /** Return the offset of a field in a structure. */ #define offsetof(TYPE, MEMBER) __builtin_offsetof (TYPE, MEMBER) -- 2.17.1