tests: virtio-9p: code refactoring
[qemu.git] / include / exec / tb-hash-xx.h
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 EXEC_TB_HASH_XX_H
35 #define EXEC_TB_HASH_XX_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 TB_HASH_XX_SEED 1
46
47 /*
48 * xxhash32, customized for input variables that are not guaranteed to be
49 * contiguous in memory.
50 */
51 static inline
52 uint32_t tb_hash_func5(uint64_t a0, uint64_t b0, uint32_t e)
53 {
54 uint32_t v1 = TB_HASH_XX_SEED + PRIME32_1 + PRIME32_2;
55 uint32_t v2 = TB_HASH_XX_SEED + PRIME32_2;
56 uint32_t v3 = TB_HASH_XX_SEED + 0;
57 uint32_t v4 = TB_HASH_XX_SEED - PRIME32_1;
58 uint32_t a = a0 >> 32;
59 uint32_t b = a0;
60 uint32_t c = b0 >> 32;
61 uint32_t d = b0;
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 += 20;
82
83 h32 += e * PRIME32_3;
84 h32 = rol32(h32, 17) * PRIME32_4;
85
86 h32 ^= h32 >> 15;
87 h32 *= PRIME32_2;
88 h32 ^= h32 >> 13;
89 h32 *= PRIME32_3;
90 h32 ^= h32 >> 16;
91
92 return h32;
93 }
94
95 #endif /* EXEC_TB_HASH_XX_H */