diff --git a/hash.h b/hash.h index 6f952c7..37958bb 100644 --- a/hash.h +++ b/hash.h @@ -16,37 +16,9 @@ #include -/* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */ -#define GOLDEN_RATIO_PRIME_32 0x9e370001UL -/* 2^63 + 2^61 - 2^57 + 2^54 - 2^51 - 2^18 + 1 */ -#define GOLDEN_RATIO_PRIME_64 0x9e37fffffffc0001UL - -#if __WORDSIZE == 32 -#define GOLDEN_RATIO_PRIME GOLDEN_RATIO_PRIME_32 -#define hash_long(val, bits) hash_32(val, bits) -#elif __WORDSIZE == 64 -#define hash_long(val, bits) hash_64(val, bits) -#define GOLDEN_RATIO_PRIME GOLDEN_RATIO_PRIME_64 -#else -#error Wordsize not 32 or 64 -#endif - static inline uint64_t hash_64(const uint64_t val, const unsigned int bits) { return (val * 11400714819323198485LLU) >> (64 - bits); } -static inline uint32_t hash_32(uint32_t val, unsigned int bits) -{ - /* On some cpus multiply is faster, on others gcc will do shifts */ - uint32_t hash = val * GOLDEN_RATIO_PRIME_32; - - /* High bits are more random, so use them. */ - return hash >> (32 - bits); -} - -static inline unsigned long hash_ptr(void *ptr, unsigned int bits) -{ - return hash_long((unsigned long)ptr, bits); -} #endif /* _LINUX_HASH_H */