From patchwork Tue Dec 11 17:57:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anatoly Burakov X-Patchwork-Id: 48654 X-Patchwork-Delegate: thomas@monjalon.net Return-Path: X-Original-To: patchwork@dpdk.org Delivered-To: patchwork@dpdk.org Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 1F4651B113; Tue, 11 Dec 2018 18:57:39 +0100 (CET) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 9CC85683E 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 orsmga007.jf.intel.com ([10.7.209.58]) by orsmga102.jf.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="97933895" Received: from irvmail001.ir.intel.com ([163.33.26.43]) by orsmga007.jf.intel.com with ESMTP; 11 Dec 2018 09:57:29 -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 wBBHvTN1014321; 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 wBBHvTSa024648; Tue, 11 Dec 2018 17:57:29 GMT Received: (from aburakov@localhost) by sivswdev05.ir.intel.com with LOCAL id wBBHvS8K024644; Tue, 11 Dec 2018 17:57:29 GMT From: Anatoly Burakov To: dev@dpdk.org Cc: John McNamara , Marko Kovacevic , thomas@monjalon.net, jasvinder.singh@intel.com, cristian.dumitrescu@intel.com, jerin.jacob@caviumnetworks.com Date: Tue, 11 Dec 2018 17:57:10 +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 2/6] common: add bsf64 function similar to existing bsf32 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Implement a new rte_bsf64 function that is following convention set by existing rte_bsf32 function. Also, document the change in release notes. Signed-off-by: Anatoly Burakov --- doc/guides/rel_notes/release_19_02.rst | 4 +++- lib/librte_eal/common/include/rte_common.h | 19 ++++++++++++++++++- 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/doc/guides/rel_notes/release_19_02.rst b/doc/guides/rel_notes/release_19_02.rst index ff81357d4..1d56ad43e 100644 --- a/doc/guides/rel_notes/release_19_02.rst +++ b/doc/guides/rel_notes/release_19_02.rst @@ -85,7 +85,9 @@ API Changes * eal: function ``rte_bsf64`` in ``rte_bitmap.h`` has been renamed to - ``rte_bsf64_safe`` and moved to ``rte_common.h``. + ``rte_bsf64_safe`` and moved to ``rte_common.h``. A new ``rte_bsf64`` function + has been added in ``rte_common.h`` that follows convention set by existing + ``rte_bsf32`` function. ABI Changes diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h index 66cdf60b2..2735dcca7 100644 --- a/lib/librte_eal/common/include/rte_common.h +++ b/lib/librte_eal/common/include/rte_common.h @@ -482,6 +482,23 @@ rte_fls_u32(uint32_t x) return (x == 0) ? 0 : 32 - __builtin_clz(x); } +/** + * Searches the input parameter for the least significant set bit + * (starting from zero). + * If a least significant 1 bit is found, its bit index is returned. + * If the content of the input parameter is zero, then the content of the return + * value is undefined. + * @param v + * input parameter, should not be zero. + * @return + * least significant set bit in the input parameter. + */ +static inline int +rte_bsf64(uint64_t v) +{ + return (uint32_t)__builtin_ctzll(v); +} + /** * Searches the input parameter for the least significant set bit * (starting from zero). Safe version (checks for input parameter being zero). @@ -502,7 +519,7 @@ rte_bsf64_safe(uint64_t v, uint32_t *pos) if (v == 0) return 0; - *pos = __builtin_ctzll(v); + *pos = rte_bsf64(v); return 1; }