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Add FastestHash to cheaders.v

pull/3804/head
ka-weihe 2020-02-21 12:20:03 +01:00 committed by GitHub
parent 8bb8b7d76e
commit 6b706a0c99
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1 changed files with 4 additions and 0 deletions
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vlib/compiler/cheaders.v
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@ -240,6 +240,10 @@ static inline uint64_t wyhash64(uint64_t A, uint64_t B) { return _wymum(_wymum(A
static inline uint64_t wyrand(uint64_t *seed) { *seed+=_wyp0; return _wymum(*seed^_wyp1,*seed); }
static inline double wy2u01(uint64_t r) { const double _wynorm=1.0/(1ull<<52); return (r>>11)*_wynorm; }
static inline double wy2gau(uint64_t r) { const double _wynorm=1.0/(1ull<<20); return ((r&0x1fffff)+((r>>21)&0x1fffff)+((r>>42)&0x1fffff))*_wynorm-3.0; }
static inline uint64_t fastest_hash(const void *key, size_t len, uint64_t seed) {
const uint8_t *p = (const uint8_t *)key;
return _like_(len >= 4) ? (_wyr4(p) + _wyr4(p + len - 4)) * (_wyr4(p + (len >> 1) - 2) ^ seed) : (_like_(len) ? _wyr3(p, len) * (_wyp0 ^ seed) : seed);
}
#endif
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