/* * BIRD Library -- Generic Bit Operations * * (c) 1998 Martin Mares <mj@ucw.cz> * * Can be freely distributed and used under the terms of the GNU GPL. */ #ifndef _BIRD_BITOPTS_H_ #define _BIRD_BITOPTS_H_ #include "sysdep/config.h" /* * Bit mask operations: * * u32_mkmask Make bit mask consisting of <n> consecutive ones * from the left and the rest filled with zeroes. * E.g., u32_mkmask(5) = 0xf8000000. * u32_masklen Inverse operation to u32_mkmask, -1 if not a bitmask. */ u32 u32_mkmask(uint n); uint u32_masklen(u32 x); u32 u32_log2(u32 v); static inline u32 u32_hash(u32 v) { return v * 2902958171u; } static inline u8 u32_popcount(u32 v) { return __builtin_popcount(v); } static inline u8 u64_popcount(u64 v) { return __builtin_popcountll(v); } static inline int u32_clz(u32 v) { return __builtin_clz(v); } static inline int u32_ctz(u32 v) { return __builtin_ctz(v); } static inline int uint_is_pow2(uint n) { return n && !(n & (n-1)); } #endif