1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
/**
* Copyright (C) 2005-2012 Gekko Emulator
*
* @file hash.cpp
* @author ShizZy <shizzy247@gmail.com>
* @date 2012-12-05
* @brief General purpose hash function
* @remark Some functions borrowed from Dolphin Emulator
*
* @section LICENSE
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details at
* http://www.gnu.org/copyleft/gpl.html
*
* Official project repository can be found at:
* http://code.google.com/p/gekko-gc-emu/
*/
#include "crc.h"
#include "hash.h"
#include "common.h"
namespace common {
/// Block mix - combine the key bits with the hash bits and scramble everything
inline void bmix64(u64& h1, u64& h2, u64& k1, u64& k2, u64& c1, u64& c2) {
k1 *= c1;
k1 = _rotl64(k1,23);
k1 *= c2;
h1 ^= k1;
h1 += h2;
h2 = _rotl64(h2,41);
k2 *= c2;
k2 = _rotl64(k2,23);
k2 *= c1;
h2 ^= k2;
h2 += h1;
h1 = h1*3 + 0x52dce729;
h2 = h2*3 + 0x38495ab5;
c1 = c1*5 + 0x7b7d159c;
c2 = c2*5 + 0x6bce6396;
}
/// Finalization mix - avalanches all bits to within 0.05% bias
inline u64 fmix64(u64 k) {
k ^= k >> 33;
k *= 0xff51afd7ed558ccd;
k ^= k >> 33;
k *= 0xc4ceb9fe1a85ec53;
k ^= k >> 33;
return k;
}
#define ROTL32(x,y) rotl32(x,y)
inline uint32_t fmix ( uint32_t h )
{
h ^= h >> 16;
h *= 0x85ebca6b;
h ^= h >> 13;
h *= 0xc2b2ae35;
h ^= h >> 16;
return h;
}
u32 __compute_murmur_hash3_32(const u8 *src, int len, u32 samples) {
u32 h = len;
u32 step = (len >> 2);
const u32 *data = (const u32*)src;
const u32 *end = data + step;
if (samples == 0) {
samples = std::max(step, 1u);
}
step = step / samples;
if(step < 1) {
step = 1;
}
u32 h1 = 0x2f6af274;
const u32 c1 = 0xcc9e2d51;
const u32 c2 = 0x1b873593;
while (data < end) {
u32 k1 = data[0];
k1 *= c1;
k1 = (k1 << 15) | (k1 >> (32 - 15));
k1 *= c2;
h1 ^= k1;
h1 = (h1 << 15) | (h1 >> (32 - 13));
h1 = h1*5+0xe6546b64;
data += step;
}
const u8 * tail = (const u8*)(data);
u32 k1 = 0;
switch(len & 3) {
case 3:
k1 ^= tail[2] << 16;
case 2:
k1 ^= tail[1] << 8;
case 1:
k1 ^= tail[0];
k1 *= c1;
k1 = (k1 << 15) | (k1 >> (32 - 15));
k1 *= c2;
h1 ^= k1;
};
h1 ^= len;
h1 = fmix(h1);
return h1;
}
/// MurmurHash is a non-cryptographic hash function suitable for general hash-based lookup
u64 __compute_murmur_hash3_64(const u8 *src, int len, u32 samples) {
const u8 * data = (const u8*)src;
const int nblocks = len / 16;
u32 step = (len / 8);
if(samples == 0) {
samples = std::max(step, 1u);
}
step = step / samples;
if(step < 1) {
step = 1;
}
u64 h1 = 0x9368e53c2f6af274;
u64 h2 = 0x586dcd208f7cd3fd;
u64 c1 = 0x87c37b91114253d5;
u64 c2 = 0x4cf5ad432745937f;
const u64* blocks = (const u64*)(data);
for (int i = 0; i < nblocks; i+=step) {
u64 k1 = blocks[(i * 2) + 0];
u64 k2 = blocks[(i * 2) + 1];
bmix64(h1,h2,k1,k2,c1,c2);
}
const u8* tail = (const u8*)(data + nblocks * 16);
u64 k1 = 0;
u64 k2 = 0;
switch (len & 15) {
case 15: k2 ^= u64(tail[14]) << 48;
case 14: k2 ^= u64(tail[13]) << 40;
case 13: k2 ^= u64(tail[12]) << 32;
case 12: k2 ^= u64(tail[11]) << 24;
case 11: k2 ^= u64(tail[10]) << 16;
case 10: k2 ^= u64(tail[ 9]) << 8;
case 9: k2 ^= u64(tail[ 8]) << 0;
case 8: k1 ^= u64(tail[ 7]) << 56;
case 7: k1 ^= u64(tail[ 6]) << 48;
case 6: k1 ^= u64(tail[ 5]) << 40;
case 5: k1 ^= u64(tail[ 4]) << 32;
case 4: k1 ^= u64(tail[ 3]) << 24;
case 3: k1 ^= u64(tail[ 2]) << 16;
case 2: k1 ^= u64(tail[ 1]) << 8;
case 1: k1 ^= u64(tail[ 0]) << 0;
bmix64(h1, h2, k1, k2, c1, c2);
};
h2 ^= len;
h1 += h2;
h2 += h1;
h1 = fmix64(h1);
h2 = fmix64(h2);
h1 += h2;
return h1;
}
/// CRC32 hash using the SSE4.2 instruction
u64 __compute_crc32_sse4(const u8 *src, int len, u32 samples) {
u32 h = len;
u32 step = (len >> 2);
const u32 *data = (const u32*)src;
const u32 *end = data + step;
if (samples == 0) {
samples = std::max(step, 1u);
}
step = step / samples;
if(step < 1) {
step = 1;
}
while (data < end) {
h = InlineCrc32_U32(h, data[0]);
data += step;
}
const u8 *data2 = (const u8*)end;
return (u64)InlineCrc32_U32(h, u32(data2[0]));
}
/**
* Compute an efficient 64-bit hash (optimized for Intel hardware)
* @param src Source data buffer to compute hash for
* @param len Length of data buffer to compute hash for
* @param samples Number of samples to compute hash for
* @remark Borrowed from Dolphin Emulator
*/
Hash64 GetHash64(const u8 *src, int len, u32 samples) {
#if defined(EMU_ARCHITECTURE_X86) || defined(EMU_ARCHITECTURE_X64)
// TODO(ShizZy): Move somewhere common so we dont need to instantiate this more than once
static X86Utils x86_utils;
if (x86_utils.IsExtensionSupported(X86Utils::kExtensionX86_SSE4_2)) {
return __compute_crc32_sse4(src, len, samples);
} else {
#ifdef EMU_ARCHITECTURE_X64
return __compute_murmur_hash3_64(src, len, samples);
#else
return __compute_murmur_hash3_32(src, len, samples);
#endif
}
#else
return __compute_murmur_hash3_32(src, len, samples);
#endif
}
} // namespace
|
