diff options
Diffstat (limited to 'lib/librte_eal/common/include/rte_common.h')
-rw-r--r-- | lib/librte_eal/common/include/rte_common.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/lib/librte_eal/common/include/rte_common.h b/lib/librte_eal/common/include/rte_common.h index cba7bbc1..87f0f630 100644 --- a/lib/librte_eal/common/include/rte_common.h +++ b/lib/librte_eal/common/include/rte_common.h @@ -473,6 +473,25 @@ rte_log2_u32(uint32_t v) return rte_bsf32(v); } + +/** + * Return the last (most-significant) bit set. + * + * @note The last (most significant) bit is at position 32. + * @note rte_fls_u32(0) = 0, rte_fls_u32(1) = 1, rte_fls_u32(0x80000000) = 32 + * + * @param x + * The input parameter. + * @return + * The last (most-significant) bit set, or 0 if the input is 0. + */ +static inline int +rte_fls_u32(uint32_t x) +{ + return (x == 0) ? 0 : 32 - __builtin_clz(x); +} + + #ifndef offsetof /** Return the offset of a field in a structure. */ #define offsetof(TYPE, MEMBER) __builtin_offsetof (TYPE, MEMBER) |