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32 lines
733 B
C
32 lines
733 B
C
/*
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* BIRD Library -- Generic Bit Operations
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*
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* (c) 1998 Martin Mares <mj@ucw.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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#ifndef _BIRD_BITOPTS_H_
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#define _BIRD_BITOPTS_H_
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/*
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* Bit mask operations:
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*
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* u32_mkmask Make bit mask consisting of <n> consecutive ones
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* from the left and the rest filled with zeroes.
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* E.g., u32_mkmask(5) = 0xf8000000.
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* u32_masklen Inverse operation to u32_mkmask, -1 if not a bitmask.
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*/
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u32 u32_mkmask(uint n);
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int u32_masklen(u32 x);
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u32 u32_log2(u32 v);
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u32 u32_bitrange(u32 v, int *top, int *bottom);
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static inline u32 u32_hash(u32 v) { return v * 2902958171u; }
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static inline u8 u32_popcount(u32 v) { return __builtin_popcount(v); }
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#endif
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