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/*
* Utilities for working with hash values.
*
* Portions Copyright (c) 2017, PostgreSQL Global Development Group
*/
#ifndef HASHUTILS_H
#define HASHUTILS_H
/*
* Combine two hash values, resulting in another hash value, with decent bit
* mixing.
*
* Similar to boost's hash_combine().
*/
static inline uint32
hash_combine(uint32 a, uint32 b)
{
a ^= b + 0x9e3779b9 + (a << 6) + (a >> 2);
return a;
}
/*
* Simple inline murmur hash implementation hashing a 32 bit integer, for
* performance.
*/
static inline uint32
murmurhash32(uint32 data)
{
uint32 h = data;
h ^= h >> 16;
h *= 0x85ebca6b;
h ^= h >> 13;
h *= 0xc2b2ae35;
h ^= h >> 16;
return h;
}
#endif /* HASHUTILS_H */
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