hash.h

/* IBM_PROLOG_BEGIN_TAG                                                   */
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/* $Source: clib/hash.h $                                                 */
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/* IBM_PROLOG_END_TAG                                                     */

/*
 *   File: hash.h
 * Author: Shaun Wetzstein <shaun@us.ibm.com>
 *  Descr: Various int64 hash functions
 *   Note:
 *   Date: 10/03/10
 */

#ifndef __HASH_H__
#define __HASH_H__

#include <stdint.h>

/* ======================================================================= */

static inline int64_t int64_hash1(int64_t);

typedef uint64_t(*hash_t) (char *, uint64_t);

/* ======================================================================= */

static inline int64_t int64_hash1(int64_t key)
{
	key = ~key + (key << 15);
	key = key ^ (key >> 12);
	key = key + (key << 2);
	key = key ^ (key >> 4);
	key = key * 2057;
	key = key ^ (key >> 16);

	return key;
}

/* ======================================================================= */

#endif				/* __HASH_H__ */