From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavan Nikhilesh Subject: [PATCH 1/2] eal: add API to align integer to previous power of 2 Date: Sat, 17 Feb 2018 16:19:33 +0530 Message-ID: <20180217104934.17291-1-pbhagavatula@caviumnetworks.com> Mime-Version: 1.0 Content-Type: text/plain Cc: dev@dpdk.org, Pavan Nikhilesh To: jerin.jacob@caviumnetworks.com, thomas@monjalon.net Return-path: Received: from NAM03-CO1-obe.outbound.protection.outlook.com (mail-co1nam03on0068.outbound.protection.outlook.com [104.47.40.68]) by dpdk.org (Postfix) with ESMTP id D443A1B015 for ; Sat, 17 Feb 2018 11:50:07 +0100 (CET) List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Add 32b and 64b API's to align the given integer to the previous power of 2. Signed-off-by: Pavan Nikhilesh --- lib/librte_eal/common/include/rte_common.h | 36 ++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h index c7803e41c..126914f07 100644 --- a/lib/librte_eal/common/include/rte_common.h +++ b/lib/librte_eal/common/include/rte_common.h @@ -259,6 +259,24 @@ rte_align32pow2(uint32_t x) return x + 1; } +/** + * Aligns input parameter to the previous power of 2 + * + * @param x + * The integer value to algin + * + * @return + * Input parameter aligned to the previous power of 2 + */ +static inline uint32_t +rte_align32lowpow2(uint32_t x) +{ + x = rte_align32pow2(x); + x--; + + return x - (x >> 1); +} + /** * Aligns 64b input parameter to the next power of 2 * @@ -282,6 +300,24 @@ rte_align64pow2(uint64_t v) return v + 1; } +/** + * Aligns 64b input parameter to the previous power of 2 + * + * @param v + * The 64b value to align + * + * @return + * Input parameter aligned to the previous power of 2 + */ +static inline uint64_t +rte_align64lowpow2(uint64_t v) +{ + v = rte_align64pow2(v); + v--; + + return v - (v >> 1); +} + /*********** Macros for calculating min and max **********/ /** -- 2.16.1