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Diffstat (limited to 'libraries/eina/src/tests/city.cc')
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diff --git a/libraries/eina/src/tests/city.cc b/libraries/eina/src/tests/city.cc deleted file mode 100644 index 36ff93b..0000000 --- a/libraries/eina/src/tests/city.cc +++ /dev/null | |||
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1 | // Copyright (c) 2011 Google, Inc. | ||
2 | // | ||
3 | // Permission is hereby granted, free of charge, to any person obtaining a copy | ||
4 | // of this software and associated documentation files (the "Software"), to deal | ||
5 | // in the Software without restriction, including without limitation the rights | ||
6 | // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | ||
7 | // copies of the Software, and to permit persons to whom the Software is | ||
8 | // furnished to do so, subject to the following conditions: | ||
9 | // | ||
10 | // The above copyright notice and this permission notice shall be included in | ||
11 | // all copies or substantial portions of the Software. | ||
12 | // | ||
13 | // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | ||
14 | // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | ||
15 | // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | ||
16 | // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | ||
17 | // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | ||
18 | // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | ||
19 | // THE SOFTWARE. | ||
20 | // | ||
21 | // CityHash Version 1, by Geoff Pike and Jyrki Alakuijala | ||
22 | // | ||
23 | // This file provides CityHash64() and related functions. | ||
24 | // | ||
25 | // It's probably possible to create even faster hash functions by | ||
26 | // writing a program that systematically explores some of the space of | ||
27 | // possible hash functions, by using SIMD instructions, or by | ||
28 | // compromising on hash quality. | ||
29 | |||
30 | #include "city.h" | ||
31 | |||
32 | #include <algorithm> | ||
33 | |||
34 | using namespace std; | ||
35 | |||
36 | #define UNALIGNED_LOAD64(p) (*(const uint64*)(p)) | ||
37 | #define UNALIGNED_LOAD32(p) (*(const uint32*)(p)) | ||
38 | |||
39 | #if !defined(LIKELY) | ||
40 | #if defined(__GNUC__) | ||
41 | #define LIKELY(x) (__builtin_expect(!!(x), 1)) | ||
42 | #else | ||
43 | #define LIKELY(x) (x) | ||
44 | #endif | ||
45 | #endif | ||
46 | |||
47 | // Some primes between 2^63 and 2^64 for various uses. | ||
48 | static const uint64 k0 = 0xc3a5c85c97cb3127ULL; | ||
49 | static const uint64 k1 = 0xb492b66fbe98f273ULL; | ||
50 | static const uint64 k2 = 0x9ae16a3b2f90404fULL; | ||
51 | static const uint64 k3 = 0xc949d7c7509e6557ULL; | ||
52 | |||
53 | // Bitwise right rotate. Normally this will compile to a single | ||
54 | // instruction, especially if the shift is a manifest constant. | ||
55 | static uint64 Rotate(uint64 val, int shift) { | ||
56 | // Avoid shifting by 64: doing so yields an undefined result. | ||
57 | return shift == 0 ? val : ((val >> shift) | (val << (64 - shift))); | ||
58 | } | ||
59 | |||
60 | // Equivalent to Rotate(), but requires the second arg to be non-zero. | ||
61 | // On x86-64, and probably others, it's possible for this to compile | ||
62 | // to a single instruction if both args are already in registers. | ||
63 | static uint64 RotateByAtLeast1(uint64 val, int shift) { | ||
64 | return (val >> shift) | (val << (64 - shift)); | ||
65 | } | ||
66 | |||
67 | static uint64 ShiftMix(uint64 val) { | ||
68 | return val ^ (val >> 47); | ||
69 | } | ||
70 | |||
71 | static uint64 HashLen16(uint64 u, uint64 v) { | ||
72 | return Hash128to64(uint128(u, v)); | ||
73 | } | ||
74 | |||
75 | static uint64 HashLen0to16(const char *s, size_t len) { | ||
76 | if (len > 8) { | ||
77 | uint64 a = UNALIGNED_LOAD64(s); | ||
78 | uint64 b = UNALIGNED_LOAD64(s + len - 8); | ||
79 | return HashLen16(a, RotateByAtLeast1(b + len, len)) ^ b; | ||
80 | } | ||
81 | if (len >= 4) { | ||
82 | uint64 a = UNALIGNED_LOAD32(s); | ||
83 | return HashLen16(len + (a << 3), UNALIGNED_LOAD32(s + len - 4)); | ||
84 | } | ||
85 | if (len > 0) { | ||
86 | uint8 a = s[0]; | ||
87 | uint8 b = s[len >> 1]; | ||
88 | uint8 c = s[len - 1]; | ||
89 | uint32 y = static_cast<uint32>(a) + (static_cast<uint32>(b) << 8); | ||
90 | uint32 z = len + (static_cast<uint32>(c) << 2); | ||
91 | return ShiftMix(y * k2 ^ z * k3) * k2; | ||
92 | } | ||
93 | return k2; | ||
94 | } | ||
95 | |||
96 | // This probably works well for 16-byte strings as well, but it may be overkill | ||
97 | // in that case. | ||
98 | static uint64 HashLen17to32(const char *s, size_t len) { | ||
99 | uint64 a = UNALIGNED_LOAD64(s) * k1; | ||
100 | uint64 b = UNALIGNED_LOAD64(s + 8); | ||
101 | uint64 c = UNALIGNED_LOAD64(s + len - 8) * k2; | ||
102 | uint64 d = UNALIGNED_LOAD64(s + len - 16) * k0; | ||
103 | return HashLen16(Rotate(a - b, 43) + Rotate(c, 30) + d, | ||
104 | a + Rotate(b ^ k3, 20) - c + len); | ||
105 | } | ||
106 | |||
107 | // Return a 16-byte hash for 48 bytes. Quick and dirty. | ||
108 | // Callers do best to use "random-looking" values for a and b. | ||
109 | static pair<uint64, uint64> WeakHashLen32WithSeeds( | ||
110 | uint64 w, uint64 x, uint64 y, uint64 z, uint64 a, uint64 b) { | ||
111 | a += w; | ||
112 | b = Rotate(b + a + z, 21); | ||
113 | uint64 c = a; | ||
114 | a += x; | ||
115 | a += y; | ||
116 | b += Rotate(a, 44); | ||
117 | return make_pair(a + z, b + c); | ||
118 | } | ||
119 | |||
120 | // Return a 16-byte hash for s[0] ... s[31], a, and b. Quick and dirty. | ||
121 | static pair<uint64, uint64> WeakHashLen32WithSeeds( | ||
122 | const char* s, uint64 a, uint64 b) { | ||
123 | return WeakHashLen32WithSeeds(UNALIGNED_LOAD64(s), | ||
124 | UNALIGNED_LOAD64(s + 8), | ||
125 | UNALIGNED_LOAD64(s + 16), | ||
126 | UNALIGNED_LOAD64(s + 24), | ||
127 | a, | ||
128 | b); | ||
129 | } | ||
130 | |||
131 | // Return an 8-byte hash for 33 to 64 bytes. | ||
132 | static uint64 HashLen33to64(const char *s, size_t len) { | ||
133 | uint64 z = UNALIGNED_LOAD64(s + 24); | ||
134 | uint64 a = UNALIGNED_LOAD64(s) + (len + UNALIGNED_LOAD64(s + len - 16)) * k0; | ||
135 | uint64 b = Rotate(a + z, 52); | ||
136 | uint64 c = Rotate(a, 37); | ||
137 | a += UNALIGNED_LOAD64(s + 8); | ||
138 | c += Rotate(a, 7); | ||
139 | a += UNALIGNED_LOAD64(s + 16); | ||
140 | uint64 vf = a + z; | ||
141 | uint64 vs = b + Rotate(a, 31) + c; | ||
142 | a = UNALIGNED_LOAD64(s + 16) + UNALIGNED_LOAD64(s + len - 32); | ||
143 | z = UNALIGNED_LOAD64(s + len - 8); | ||
144 | b = Rotate(a + z, 52); | ||
145 | c = Rotate(a, 37); | ||
146 | a += UNALIGNED_LOAD64(s + len - 24); | ||
147 | c += Rotate(a, 7); | ||
148 | a += UNALIGNED_LOAD64(s + len - 16); | ||
149 | uint64 wf = a + z; | ||
150 | uint64 ws = b + Rotate(a, 31) + c; | ||
151 | uint64 r = ShiftMix((vf + ws) * k2 + (wf + vs) * k0); | ||
152 | return ShiftMix(r * k0 + vs) * k2; | ||
153 | } | ||
154 | |||
155 | uint64 CityHash64(const char *s, size_t len) { | ||
156 | if (len <= 32) { | ||
157 | if (len <= 16) { | ||
158 | return HashLen0to16(s, len); | ||
159 | } else { | ||
160 | return HashLen17to32(s, len); | ||
161 | } | ||
162 | } else if (len <= 64) { | ||
163 | return HashLen33to64(s, len); | ||
164 | } | ||
165 | |||
166 | // For strings over 64 bytes we hash the end first, and then as we | ||
167 | // loop we keep 56 bytes of state: v, w, x, y, and z. | ||
168 | uint64 x = UNALIGNED_LOAD64(s); | ||
169 | uint64 y = UNALIGNED_LOAD64(s + len - 16) ^ k1; | ||
170 | uint64 z = UNALIGNED_LOAD64(s + len - 56) ^ k0; | ||
171 | pair<uint64, uint64> v = WeakHashLen32WithSeeds(s + len - 64, len, y); | ||
172 | pair<uint64, uint64> w = WeakHashLen32WithSeeds(s + len - 32, len * k1, k0); | ||
173 | z += ShiftMix(v.second) * k1; | ||
174 | x = Rotate(z + x, 39) * k1; | ||
175 | y = Rotate(y, 33) * k1; | ||
176 | |||
177 | // Decrease len to the nearest multiple of 64, and operate on 64-byte chunks. | ||
178 | len = (len - 1) & ~static_cast<size_t>(63); | ||
179 | do { | ||
180 | x = Rotate(x + y + v.first + UNALIGNED_LOAD64(s + 16), 37) * k1; | ||
181 | y = Rotate(y + v.second + UNALIGNED_LOAD64(s + 48), 42) * k1; | ||
182 | x ^= w.second; | ||
183 | y ^= v.first; | ||
184 | z = Rotate(z ^ w.first, 33); | ||
185 | v = WeakHashLen32WithSeeds(s, v.second * k1, x + w.first); | ||
186 | w = WeakHashLen32WithSeeds(s + 32, z + w.second, y); | ||
187 | std::swap(z, x); | ||
188 | s += 64; | ||
189 | len -= 64; | ||
190 | } while (len != 0); | ||
191 | return HashLen16(HashLen16(v.first, w.first) + ShiftMix(y) * k1 + z, | ||
192 | HashLen16(v.second, w.second) + x); | ||
193 | } | ||
194 | |||
195 | uint64 CityHash64WithSeed(const char *s, size_t len, uint64 seed) { | ||
196 | return CityHash64WithSeeds(s, len, k2, seed); | ||
197 | } | ||
198 | |||
199 | uint64 CityHash64WithSeeds(const char *s, size_t len, | ||
200 | uint64 seed0, uint64 seed1) { | ||
201 | return HashLen16(CityHash64(s, len) - seed0, seed1); | ||
202 | } | ||
203 | |||
204 | // A subroutine for CityHash128(). Returns a decent 128-bit hash for strings | ||
205 | // of any length representable in ssize_t. Based on City and Murmur. | ||
206 | static uint128 CityMurmur(const char *s, size_t len, uint128 seed) { | ||
207 | uint64 a = Uint128Low64(seed); | ||
208 | uint64 b = Uint128High64(seed); | ||
209 | uint64 c = 0; | ||
210 | uint64 d = 0; | ||
211 | ssize_t l = len - 16; | ||
212 | if (l <= 0) { // len <= 16 | ||
213 | c = b * k1 + HashLen0to16(s, len); | ||
214 | d = Rotate(a + (len >= 8 ? UNALIGNED_LOAD64(s) : c), 32); | ||
215 | } else { // len > 16 | ||
216 | c = HashLen16(UNALIGNED_LOAD64(s + len - 8) + k1, a); | ||
217 | d = HashLen16(b + len, c + UNALIGNED_LOAD64(s + len - 16)); | ||
218 | a += d; | ||
219 | do { | ||
220 | a ^= ShiftMix(UNALIGNED_LOAD64(s) * k1) * k1; | ||
221 | a *= k1; | ||
222 | b ^= a; | ||
223 | c ^= ShiftMix(UNALIGNED_LOAD64(s + 8) * k1) * k1; | ||
224 | c *= k1; | ||
225 | d ^= c; | ||
226 | s += 16; | ||
227 | l -= 16; | ||
228 | } while (l > 0); | ||
229 | } | ||
230 | a = HashLen16(a, c); | ||
231 | b = HashLen16(d, b); | ||
232 | return uint128(a ^ b, HashLen16(b, a)); | ||
233 | } | ||
234 | |||
235 | uint128 CityHash128WithSeed(const char *s, size_t len, uint128 seed) { | ||
236 | if (len < 128) { | ||
237 | return CityMurmur(s, len, seed); | ||
238 | } | ||
239 | |||
240 | // We expect len >= 128 to be the common case. Keep 56 bytes of state: | ||
241 | // v, w, x, y, and z. | ||
242 | pair<uint64, uint64> v, w; | ||
243 | uint64 x = Uint128Low64(seed); | ||
244 | uint64 y = Uint128High64(seed); | ||
245 | uint64 z = len * k1; | ||
246 | v.first = Rotate(y ^ k1, 49) * k1 + UNALIGNED_LOAD64(s); | ||
247 | v.second = Rotate(v.first, 42) * k1 + UNALIGNED_LOAD64(s + 8); | ||
248 | w.first = Rotate(y + z, 35) * k1 + x; | ||
249 | w.second = Rotate(x + UNALIGNED_LOAD64(s + 88), 53) * k1; | ||
250 | |||
251 | // This is the same inner loop as CityHash64(), manually unrolled. | ||
252 | do { | ||
253 | x = Rotate(x + y + v.first + UNALIGNED_LOAD64(s + 16), 37) * k1; | ||
254 | y = Rotate(y + v.second + UNALIGNED_LOAD64(s + 48), 42) * k1; | ||
255 | x ^= w.second; | ||
256 | y ^= v.first; | ||
257 | z = Rotate(z ^ w.first, 33); | ||
258 | v = WeakHashLen32WithSeeds(s, v.second * k1, x + w.first); | ||
259 | w = WeakHashLen32WithSeeds(s + 32, z + w.second, y); | ||
260 | std::swap(z, x); | ||
261 | s += 64; | ||
262 | x = Rotate(x + y + v.first + UNALIGNED_LOAD64(s + 16), 37) * k1; | ||
263 | y = Rotate(y + v.second + UNALIGNED_LOAD64(s + 48), 42) * k1; | ||
264 | x ^= w.second; | ||
265 | y ^= v.first; | ||
266 | z = Rotate(z ^ w.first, 33); | ||
267 | v = WeakHashLen32WithSeeds(s, v.second * k1, x + w.first); | ||
268 | w = WeakHashLen32WithSeeds(s + 32, z + w.second, y); | ||
269 | std::swap(z, x); | ||
270 | s += 64; | ||
271 | len -= 128; | ||
272 | } while (LIKELY(len >= 128)); | ||
273 | y += Rotate(w.first, 37) * k0 + z; | ||
274 | x += Rotate(v.first + z, 49) * k0; | ||
275 | // If 0 < len < 128, hash up to 4 chunks of 32 bytes each from the end of s. | ||
276 | for (size_t tail_done = 0; tail_done < len; ) { | ||
277 | tail_done += 32; | ||
278 | y = Rotate(y - x, 42) * k0 + v.second; | ||
279 | w.first += UNALIGNED_LOAD64(s + len - tail_done + 16); | ||
280 | x = Rotate(x, 49) * k0 + w.first; | ||
281 | w.first += v.first; | ||
282 | v = WeakHashLen32WithSeeds(s + len - tail_done, v.first, v.second); | ||
283 | } | ||
284 | // At this point our 48 bytes of state should contain more than | ||
285 | // enough information for a strong 128-bit hash. We use two | ||
286 | // different 48-byte-to-8-byte hashes to get a 16-byte final result. | ||
287 | x = HashLen16(x, v.first); | ||
288 | y = HashLen16(y, w.first); | ||
289 | return uint128(HashLen16(x + v.second, w.second) + y, | ||
290 | HashLen16(x + w.second, y + v.second)); | ||
291 | } | ||
292 | |||
293 | uint128 CityHash128(const char *s, size_t len) { | ||
294 | if (len >= 16) { | ||
295 | return CityHash128WithSeed(s + 16, | ||
296 | len - 16, | ||
297 | uint128(UNALIGNED_LOAD64(s) ^ k3, | ||
298 | UNALIGNED_LOAD64(s + 8))); | ||
299 | } else if (len >= 8) { | ||
300 | return CityHash128WithSeed(NULL, | ||
301 | 0, | ||
302 | uint128(UNALIGNED_LOAD64(s) ^ (len * k0), | ||
303 | UNALIGNED_LOAD64(s + len - 8) ^ k1)); | ||
304 | } else { | ||
305 | return CityHash128WithSeed(s, len, uint128(k0, k1)); | ||
306 | } | ||
307 | } | ||