From 4e261f551986d40fa0c8388ed50899b609add04b Mon Sep 17 00:00:00 2001 From: Anatoly Burakov Date: Thu, 20 Dec 2018 12:09:48 +0000 Subject: [PATCH] eal: add 64-bit bsf and 32-bit safe bsf functions 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 --- app/test-pmd/testpmd.c | 8 +--- doc/guides/rel_notes/release_19_02.rst | 4 +- lib/librte_eal/common/include/rte_common.h | 43 +++++++++++++++++++++- lib/librte_eal/linuxapp/eal/eal_memalloc.c | 8 +--- test/test/test_common.c | 41 ++++++++++++++++++++- 5 files changed, 86 insertions(+), 18 deletions(-) diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index a10bc40bb1..d4d22afbb4 100644 --- a/app/test-pmd/testpmd.c +++ b/app/test-pmd/testpmd.c @@ -649,19 +649,13 @@ calc_mem_size(uint32_t nb_mbufs, uint32_t mbuf_sz, size_t pgsz, size_t *out) return 0; } -static inline uint32_t -bsf64(uint64_t v) -{ - return (uint32_t)__builtin_ctzll(v); -} - static inline uint32_t log2_u64(uint64_t v) { if (v == 0) return 0; v = rte_align64pow2(v); - return bsf64(v); + return rte_bsf64(v); } static int diff --git a/doc/guides/rel_notes/release_19_02.rst b/doc/guides/rel_notes/release_19_02.rst index b64c1e7005..47768288a3 100644 --- a/doc/guides/rel_notes/release_19_02.rst +++ b/doc/guides/rel_notes/release_19_02.rst @@ -115,7 +115,9 @@ 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. * eal: Segment fd API on Linux now sets error code to ``ENOTSUP`` in more cases where segment fd API is not expected to be supported: diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h index 66cdf60b23..d102f2cecb 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/lib/librte_eal/linuxapp/eal/eal_memalloc.c b/lib/librte_eal/linuxapp/eal/eal_memalloc.c index eef140b333..04cd813943 100644 --- a/lib/librte_eal/linuxapp/eal/eal_memalloc.c +++ b/lib/librte_eal/linuxapp/eal/eal_memalloc.c @@ -213,19 +213,13 @@ get_file_size(int fd) return st.st_size; } -static inline uint32_t -bsf64(uint64_t v) -{ - return (uint32_t)__builtin_ctzll(v); -} - static inline uint32_t log2_u64(uint64_t v) { if (v == 0) return 0; v = rte_align64pow2(v); - return bsf64(v); + return rte_bsf64(v); } static int diff --git a/test/test/test_common.c b/test/test/test_common.c index c6d17baaed..4a42aaed8f 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(); -- 2.20.1