mirror of
https://github.com/xemu-project/xemu.git
synced 2024-11-24 20:19:44 +00:00
60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
|
/* jhash.h: Jenkins hash support.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2006. Bob Jenkins (bob_jenkins@burtleburtle.net)
|
||
|
|
*
|
||
|
|
* http://burtleburtle.net/bob/hash/
|
||
|
|
*
|
||
|
|
* These are the credits from Bob's sources:
|
||
|
|
*
|
||
|
|
* lookup3.c, by Bob Jenkins, May 2006, Public Domain.
|
||
|
|
*
|
||
|
|
* These are functions for producing 32-bit hashes for hash table lookup.
|
||
|
|
* hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
|
||
|
|
* are externally useful functions. Routines to test the hash are included
|
||
|
|
* if SELF_TEST is defined. You can use this free for any purpose. It's in
|
||
|
|
* the public domain. It has no warranty.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2009-2010 Jozsef Kadlecsik (kadlec@blackhole.kfki.hu)
|
||
|
|
*
|
||
|
|
* I've modified Bob's hash to be useful in the Linux kernel, and
|
||
|
|
* any bugs present are my fault.
|
||
|
|
* Jozsef
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef QEMU_JHASH_H__
|
||
|
|
#define QEMU_JHASH_H__
|
||
|
|
|
||
|
|
#include "qemu/bitops.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* hashtable relation copy from linux kernel jhash
|
||
|
|
*/
|
||
|
|
|
||
|
|
/* __jhash_mix -- mix 3 32-bit values reversibly. */
|
||
|
|
#define __jhash_mix(a, b, c) \
|
||
|
|
{ \
|
||
|
|
a -= c; a ^= rol32(c, 4); c += b; \
|
||
|
|
b -= a; b ^= rol32(a, 6); a += c; \
|
||
|
|
c -= b; c ^= rol32(b, 8); b += a; \
|
||
|
|
a -= c; a ^= rol32(c, 16); c += b; \
|
||
|
|
b -= a; b ^= rol32(a, 19); a += c; \
|
||
|
|
c -= b; c ^= rol32(b, 4); b += a; \
|
||
|
|
}
|
||
|
|
|
||
|
|
/* __jhash_final - final mixing of 3 32-bit values (a,b,c) into c */
|
||
|
|
#define __jhash_final(a, b, c) \
|
||
|
|
{ \
|
||
|
|
c ^= b; c -= rol32(b, 14); \
|
||
|
|
a ^= c; a -= rol32(c, 11); \
|
||
|
|
b ^= a; b -= rol32(a, 25); \
|
||
|
|
c ^= b; c -= rol32(b, 16); \
|
||
|
|
a ^= c; a -= rol32(c, 4); \
|
||
|
|
b ^= a; b -= rol32(a, 14); \
|
||
|
|
c ^= b; c -= rol32(b, 24); \
|
||
|
|
}
|
||
|
|
|
||
|
|
/* An arbitrary initial parameter */
|
||
|
|
#define JHASH_INITVAL 0xdeadbeef
|
||
|
|
|
||
|
|
#endif /* QEMU_JHASH_H__ */
|