From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 359C31BC75 for ; Thu, 20 Dec 2018 13:09:59 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Dec 2018 04:09:58 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,376,1539673200"; d="scan'208";a="119938850" Received: from irvmail001.ir.intel.com ([163.33.26.43]) by FMSMGA003.fm.intel.com with ESMTP; 20 Dec 2018 04:09:57 -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 wBKC9uwx014132; Thu, 20 Dec 2018 12:09:56 GMT Received: from sivswdev05.ir.intel.com (localhost [127.0.0.1]) by sivswdev05.ir.intel.com with ESMTP id wBKC9unE001192; Thu, 20 Dec 2018 12:09:56 GMT Received: (from aburakov@localhost) by sivswdev05.ir.intel.com with LOCAL id wBKC9urU001188; Thu, 20 Dec 2018 12:09:56 GMT From: Anatoly Burakov To: dev@dpdk.org Cc: John McNamara , Marko Kovacevic , jerin.jacob@caviumnetworks.com, thomas@monjalon.net Date: Thu, 20 Dec 2018 12:09:48 +0000 Message-Id: X-Mailer: git-send-email 1.7.0.7 In-Reply-To: References: In-Reply-To: <1cf22c82b6ca7561966be674afb8a02add0913b9.1544550999.git.anatoly.burakov@intel.com> References: <1cf22c82b6ca7561966be674afb8a02add0913b9.1544550999.git.anatoly.burakov@intel.com> Subject: [dpdk-dev] [PATCH v2 2/4] common: add bsf64 and bsf32_safe functions 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: Thu, 20 Dec 2018 12:09:59 -0000 Add an rte_bsf64 function that follows the convention of existing rte_bsf32 function. Also, add missing implementation for safe version of rte_bsf32, and implement unit tests for all recently added bsf varieties. Signed-off-by: Anatoly Burakov --- doc/guides/rel_notes/release_19_02.rst | 4 +- lib/librte_eal/common/include/rte_common.h | 43 +++++++++++++++++++++- test/test/test_common.c | 41 ++++++++++++++++++++- 3 files changed, 84 insertions(+), 4 deletions(-) diff --git a/doc/guides/rel_notes/release_19_02.rst b/doc/guides/rel_notes/release_19_02.rst index c4cce4c98..0f446ed74 100644 --- a/doc/guides/rel_notes/release_19_02.rst +++ b/doc/guides/rel_notes/release_19_02.rst @@ -100,7 +100,9 @@ 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..d102f2cec 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. * @@ -482,6 +506,23 @@ 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 +543,7 @@ rte_bsf64_safe(uint64_t v, uint32_t *pos) if (v == 0) return 0; - *pos = __builtin_ctzll(v); + *pos = rte_bsf64(v); return 1; } diff --git a/test/test/test_common.c b/test/test/test_common.c index c6d17baae..4a42aaed8 100644 --- a/test/test/test_common.c +++ b/test/test/test_common.c @@ -50,12 +50,48 @@ test_macros(int __rte_unused unused_parm) return 0; } +static int +test_bsf(void) +{ + uint32_t shift, pos; + + /* safe versions should be able to handle 0 */ + if (rte_bsf32_safe(0, &pos) != 0) + FAIL("rte_bsf32_safe"); + if (rte_bsf64_safe(0, &pos) != 0) + FAIL("rte_bsf64_safe"); + + for (shift = 0; shift < 63; shift++) { + uint32_t val32; + uint64_t val64; + + val64 = 1ULL << shift; + if ((uint32_t)rte_bsf64(val64) != shift) + FAIL("rte_bsf64"); + if (rte_bsf64_safe(val64, &pos) != 1) + FAIL("rte_bsf64_safe"); + if (pos != shift) + FAIL("rte_bsf64_safe"); + + if (shift > 31) + continue; + + val32 = 1U << shift; + if ((uint32_t)rte_bsf32(val32) != shift) + FAIL("rte_bsf32"); + if (rte_bsf32_safe(val32, &pos) != 1) + FAIL("rte_bsf32_safe"); + if (pos != shift) + FAIL("rte_bsf32_safe"); + } + + return 0; +} + static int test_misc(void) { char memdump[] = "memdump_test"; - if (rte_bsf32(129)) - FAIL("rte_bsf32"); rte_memdump(stdout, "test", memdump, sizeof(memdump)); rte_hexdump(stdout, "test", memdump, sizeof(memdump)); @@ -226,6 +262,7 @@ test_common(void) ret |= test_align(); ret |= test_macros(0); ret |= test_misc(); + ret |= test_bsf(); ret |= test_log2(); ret |= test_fls(); -- 2.17.1