1/*
2 * xxHash - Fast Hash algorithm
3 * Copyright (C) 2012-2016, Yann Collet
4 *
5 * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met:
10 *
11 * + Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * + Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following disclaimer
15 * in the documentation and/or other materials provided with the
16 * distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * You can contact the author at :
31 * - xxHash source repository : https://github.com/Cyan4973/xxHash
32 */
33
34#ifndef QEMU_XXHASH_H
35#define QEMU_XXHASH_H
36
37#include "qemu/bitops.h"
38
39#define PRIME32_1 2654435761U
40#define PRIME32_2 2246822519U
41#define PRIME32_3 3266489917U
42#define PRIME32_4 668265263U
43#define PRIME32_5 374761393U
44
45#define QEMU_XXHASH_SEED 1
46
47/*
48 * xxhash32, customized for input variables that are not guaranteed to be
49 * contiguous in memory.
50 */
51static inline uint32_t
52qemu_xxhash7(uint64_t ab, uint64_t cd, uint32_t e, uint32_t f, uint32_t g)
53{
54 uint32_t v1 = QEMU_XXHASH_SEED + PRIME32_1 + PRIME32_2;
55 uint32_t v2 = QEMU_XXHASH_SEED + PRIME32_2;
56 uint32_t v3 = QEMU_XXHASH_SEED + 0;
57 uint32_t v4 = QEMU_XXHASH_SEED - PRIME32_1;
58 uint32_t a = ab;
59 uint32_t b = ab >> 32;
60 uint32_t c = cd;
61 uint32_t d = cd >> 32;
62 uint32_t h32;
63
64 v1 += a * PRIME32_2;
65 v1 = rol32(v1, 13);
66 v1 *= PRIME32_1;
67
68 v2 += b * PRIME32_2;
69 v2 = rol32(v2, 13);
70 v2 *= PRIME32_1;
71
72 v3 += c * PRIME32_2;
73 v3 = rol32(v3, 13);
74 v3 *= PRIME32_1;
75
76 v4 += d * PRIME32_2;
77 v4 = rol32(v4, 13);
78 v4 *= PRIME32_1;
79
80 h32 = rol32(v1, 1) + rol32(v2, 7) + rol32(v3, 12) + rol32(v4, 18);
81 h32 += 28;
82
83 h32 += e * PRIME32_3;
84 h32 = rol32(h32, 17) * PRIME32_4;
85
86 h32 += f * PRIME32_3;
87 h32 = rol32(h32, 17) * PRIME32_4;
88
89 h32 += g * PRIME32_3;
90 h32 = rol32(h32, 17) * PRIME32_4;
91
92 h32 ^= h32 >> 15;
93 h32 *= PRIME32_2;
94 h32 ^= h32 >> 13;
95 h32 *= PRIME32_3;
96 h32 ^= h32 >> 16;
97
98 return h32;
99}
100
101static inline uint32_t qemu_xxhash2(uint64_t ab)
102{
103 return qemu_xxhash7(ab, 0, 0, 0, 0);
104}
105
106static inline uint32_t qemu_xxhash4(uint64_t ab, uint64_t cd)
107{
108 return qemu_xxhash7(ab, cd, 0, 0, 0);
109}
110
111static inline uint32_t qemu_xxhash5(uint64_t ab, uint64_t cd, uint32_t e)
112{
113 return qemu_xxhash7(ab, cd, e, 0, 0);
114}
115
116static inline uint32_t qemu_xxhash6(uint64_t ab, uint64_t cd, uint32_t e,
117 uint32_t f)
118{
119 return qemu_xxhash7(ab, cd, e, f, 0);
120}
121
122#endif /* QEMU_XXHASH_H */
123