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Annotation of embedaddon/bird2/lib/bitops.h, revision 1.1

1.1     ! misho       1: /*
        !             2:  *     BIRD Library -- Generic Bit Operations
        !             3:  *
        !             4:  *     (c) 1998 Martin Mares <mj@ucw.cz>
        !             5:  *
        !             6:  *     Can be freely distributed and used under the terms of the GNU GPL.
        !             7:  */
        !             8: 
        !             9: #ifndef _BIRD_BITOPTS_H_
        !            10: #define _BIRD_BITOPTS_H_
        !            11: 
        !            12: #include "sysdep/config.h"
        !            13: 
        !            14: /*
        !            15:  *     Bit mask operations:
        !            16:  *
        !            17:  *     u32_mkmask      Make bit mask consisting of <n> consecutive ones
        !            18:  *                     from the left and the rest filled with zeroes.
        !            19:  *                     E.g., u32_mkmask(5) = 0xf8000000.
        !            20:  *     u32_masklen     Inverse operation to u32_mkmask, -1 if not a bitmask.
        !            21:  */
        !            22: 
        !            23: u32 u32_mkmask(uint n);
        !            24: uint u32_masklen(u32 x);
        !            25: 
        !            26: u32 u32_log2(u32 v);
        !            27: 
        !            28: static inline u32 u32_hash(u32 v) { return v * 2902958171u; }
        !            29: 
        !            30: static inline u8 u32_popcount(u32 v) { return __builtin_popcount(v); }
        !            31: 
        !            32: static inline int uint_is_pow2(uint n) { return n && !(n & (n-1)); }
        !            33: 
        !            34: #endif