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#ifndef _LINUX_HASH_H
#define _LINUX_HASH_H
#include <asm/types.h>
#define GOLDEN_RATIO_PRIME_32 0x9e370001UL
#define GOLDEN_RATIO_PRIME_64 0x9e37fffffffc0001UL
#if BITS_PER_LONG == 32
#define GOLDEN_RATIO_PRIME GOLDEN_RATIO_PRIME_32
#define hash_long(val, bits) hash_32(val, bits)
#elif BITS_PER_LONG == 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 u64 hash_64(u64 val, unsigned int bits)
{
u64 hash = val;
u64 n = hash;
n <<= 18;
hash -= n;
n <<= 33;
hash -= n;
n <<= 3;
hash += n;
n <<= 3;
hash -= n;
n <<= 4;
hash += n;
n <<= 2;
hash += n;
return hash >> (64 - bits);
}
static inline u32 hash_32(u32 val, unsigned int bits)
{
u32 hash = val * GOLDEN_RATIO_PRIME_32;
return hash >> (32 - bits);
}
static inline unsigned long hash_ptr(const void *ptr, unsigned int bits)
{
return hash_long((unsigned long)ptr, bits);
}
#endif
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