1 /*
2 * The following hash function is based on MurmurHash3, placed into the public
3 * domain by Austin Appleby. See https://github.com/aappleby/smhasher for
4 * details.
5 */
6 /******************************************************************************/
7 #ifdef JEMALLOC_H_TYPES
8
9 #endif /* JEMALLOC_H_TYPES */
10 /******************************************************************************/
11 #ifdef JEMALLOC_H_STRUCTS
12
13 #endif /* JEMALLOC_H_STRUCTS */
14 /******************************************************************************/
15 #ifdef JEMALLOC_H_EXTERNS
16
17 #endif /* JEMALLOC_H_EXTERNS */
18 /******************************************************************************/
19 #ifdef JEMALLOC_H_INLINES
20
21 #ifndef JEMALLOC_ENABLE_INLINE
22 uint32_t hash_x86_32(const void *key, int len, uint32_t seed);
23 void hash_x86_128(const void *key, const int len, uint32_t seed,
24 uint64_t r_out[2]);
25 void hash_x64_128(const void *key, const int len, const uint32_t seed,
26 uint64_t r_out[2]);
27 void hash(const void *key, size_t len, const uint32_t seed,
28 size_t r_hash[2]);
29 #endif
30
31 #if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_HASH_C_))
32 /******************************************************************************/
33 /* Internal implementation. */
34 JEMALLOC_INLINE uint32_t
hash_rotl_32(uint32_t x,int8_t r)35 hash_rotl_32(uint32_t x, int8_t r)
36 {
37
38 return ((x << r) | (x >> (32 - r)));
39 }
40
41 JEMALLOC_INLINE uint64_t
hash_rotl_64(uint64_t x,int8_t r)42 hash_rotl_64(uint64_t x, int8_t r)
43 {
44
45 return ((x << r) | (x >> (64 - r)));
46 }
47
48 JEMALLOC_INLINE uint32_t
hash_get_block_32(const uint32_t * p,int i)49 hash_get_block_32(const uint32_t *p, int i)
50 {
51
52 /* Handle unaligned read. */
53 if (unlikely((uintptr_t)p & (sizeof(uint32_t)-1)) != 0) {
54 uint32_t ret;
55
56 memcpy(&ret, (uint8_t *)(p + i), sizeof(uint32_t));
57 return (ret);
58 }
59
60 return (p[i]);
61 }
62
63 JEMALLOC_INLINE uint64_t
hash_get_block_64(const uint64_t * p,int i)64 hash_get_block_64(const uint64_t *p, int i)
65 {
66
67 /* Handle unaligned read. */
68 if (unlikely((uintptr_t)p & (sizeof(uint64_t)-1)) != 0) {
69 uint64_t ret;
70
71 memcpy(&ret, (uint8_t *)(p + i), sizeof(uint64_t));
72 return (ret);
73 }
74
75 return (p[i]);
76 }
77
78 JEMALLOC_INLINE uint32_t
hash_fmix_32(uint32_t h)79 hash_fmix_32(uint32_t h)
80 {
81
82 h ^= h >> 16;
83 h *= 0x85ebca6b;
84 h ^= h >> 13;
85 h *= 0xc2b2ae35;
86 h ^= h >> 16;
87
88 return (h);
89 }
90
91 JEMALLOC_INLINE uint64_t
hash_fmix_64(uint64_t k)92 hash_fmix_64(uint64_t k)
93 {
94
95 k ^= k >> 33;
96 k *= KQU(0xff51afd7ed558ccd);
97 k ^= k >> 33;
98 k *= KQU(0xc4ceb9fe1a85ec53);
99 k ^= k >> 33;
100
101 return (k);
102 }
103
104 JEMALLOC_INLINE uint32_t
hash_x86_32(const void * key,int len,uint32_t seed)105 hash_x86_32(const void *key, int len, uint32_t seed)
106 {
107 const uint8_t *data = (const uint8_t *) key;
108 const int nblocks = len / 4;
109
110 uint32_t h1 = seed;
111
112 const uint32_t c1 = 0xcc9e2d51;
113 const uint32_t c2 = 0x1b873593;
114
115 /* body */
116 {
117 const uint32_t *blocks = (const uint32_t *) (data + nblocks*4);
118 int i;
119
120 for (i = -nblocks; i; i++) {
121 uint32_t k1 = hash_get_block_32(blocks, i);
122
123 k1 *= c1;
124 k1 = hash_rotl_32(k1, 15);
125 k1 *= c2;
126
127 h1 ^= k1;
128 h1 = hash_rotl_32(h1, 13);
129 h1 = h1*5 + 0xe6546b64;
130 }
131 }
132
133 /* tail */
134 {
135 const uint8_t *tail = (const uint8_t *) (data + nblocks*4);
136
137 uint32_t k1 = 0;
138
139 switch (len & 3) {
140 case 3: k1 ^= tail[2] << 16;
141 case 2: k1 ^= tail[1] << 8;
142 case 1: k1 ^= tail[0]; k1 *= c1; k1 = hash_rotl_32(k1, 15);
143 k1 *= c2; h1 ^= k1;
144 }
145 }
146
147 /* finalization */
148 h1 ^= len;
149
150 h1 = hash_fmix_32(h1);
151
152 return (h1);
153 }
154
155 UNUSED JEMALLOC_INLINE void
hash_x86_128(const void * key,const int len,uint32_t seed,uint64_t r_out[2])156 hash_x86_128(const void *key, const int len, uint32_t seed,
157 uint64_t r_out[2])
158 {
159 const uint8_t * data = (const uint8_t *) key;
160 const int nblocks = len / 16;
161
162 uint32_t h1 = seed;
163 uint32_t h2 = seed;
164 uint32_t h3 = seed;
165 uint32_t h4 = seed;
166
167 const uint32_t c1 = 0x239b961b;
168 const uint32_t c2 = 0xab0e9789;
169 const uint32_t c3 = 0x38b34ae5;
170 const uint32_t c4 = 0xa1e38b93;
171
172 /* body */
173 {
174 const uint32_t *blocks = (const uint32_t *) (data + nblocks*16);
175 int i;
176
177 for (i = -nblocks; i; i++) {
178 uint32_t k1 = hash_get_block_32(blocks, i*4 + 0);
179 uint32_t k2 = hash_get_block_32(blocks, i*4 + 1);
180 uint32_t k3 = hash_get_block_32(blocks, i*4 + 2);
181 uint32_t k4 = hash_get_block_32(blocks, i*4 + 3);
182
183 k1 *= c1; k1 = hash_rotl_32(k1, 15); k1 *= c2; h1 ^= k1;
184
185 h1 = hash_rotl_32(h1, 19); h1 += h2;
186 h1 = h1*5 + 0x561ccd1b;
187
188 k2 *= c2; k2 = hash_rotl_32(k2, 16); k2 *= c3; h2 ^= k2;
189
190 h2 = hash_rotl_32(h2, 17); h2 += h3;
191 h2 = h2*5 + 0x0bcaa747;
192
193 k3 *= c3; k3 = hash_rotl_32(k3, 17); k3 *= c4; h3 ^= k3;
194
195 h3 = hash_rotl_32(h3, 15); h3 += h4;
196 h3 = h3*5 + 0x96cd1c35;
197
198 k4 *= c4; k4 = hash_rotl_32(k4, 18); k4 *= c1; h4 ^= k4;
199
200 h4 = hash_rotl_32(h4, 13); h4 += h1;
201 h4 = h4*5 + 0x32ac3b17;
202 }
203 }
204
205 /* tail */
206 {
207 const uint8_t *tail = (const uint8_t *) (data + nblocks*16);
208 uint32_t k1 = 0;
209 uint32_t k2 = 0;
210 uint32_t k3 = 0;
211 uint32_t k4 = 0;
212
213 switch (len & 15) {
214 case 15: k4 ^= tail[14] << 16;
215 case 14: k4 ^= tail[13] << 8;
216 case 13: k4 ^= tail[12] << 0;
217 k4 *= c4; k4 = hash_rotl_32(k4, 18); k4 *= c1; h4 ^= k4;
218
219 case 12: k3 ^= tail[11] << 24;
220 case 11: k3 ^= tail[10] << 16;
221 case 10: k3 ^= tail[ 9] << 8;
222 case 9: k3 ^= tail[ 8] << 0;
223 k3 *= c3; k3 = hash_rotl_32(k3, 17); k3 *= c4; h3 ^= k3;
224
225 case 8: k2 ^= tail[ 7] << 24;
226 case 7: k2 ^= tail[ 6] << 16;
227 case 6: k2 ^= tail[ 5] << 8;
228 case 5: k2 ^= tail[ 4] << 0;
229 k2 *= c2; k2 = hash_rotl_32(k2, 16); k2 *= c3; h2 ^= k2;
230
231 case 4: k1 ^= tail[ 3] << 24;
232 case 3: k1 ^= tail[ 2] << 16;
233 case 2: k1 ^= tail[ 1] << 8;
234 case 1: k1 ^= tail[ 0] << 0;
235 k1 *= c1; k1 = hash_rotl_32(k1, 15); k1 *= c2; h1 ^= k1;
236 }
237 }
238
239 /* finalization */
240 h1 ^= len; h2 ^= len; h3 ^= len; h4 ^= len;
241
242 h1 += h2; h1 += h3; h1 += h4;
243 h2 += h1; h3 += h1; h4 += h1;
244
245 h1 = hash_fmix_32(h1);
246 h2 = hash_fmix_32(h2);
247 h3 = hash_fmix_32(h3);
248 h4 = hash_fmix_32(h4);
249
250 h1 += h2; h1 += h3; h1 += h4;
251 h2 += h1; h3 += h1; h4 += h1;
252
253 r_out[0] = (((uint64_t) h2) << 32) | h1;
254 r_out[1] = (((uint64_t) h4) << 32) | h3;
255 }
256
257 UNUSED JEMALLOC_INLINE void
hash_x64_128(const void * key,const int len,const uint32_t seed,uint64_t r_out[2])258 hash_x64_128(const void *key, const int len, const uint32_t seed,
259 uint64_t r_out[2])
260 {
261 const uint8_t *data = (const uint8_t *) key;
262 const int nblocks = len / 16;
263
264 uint64_t h1 = seed;
265 uint64_t h2 = seed;
266
267 const uint64_t c1 = KQU(0x87c37b91114253d5);
268 const uint64_t c2 = KQU(0x4cf5ad432745937f);
269
270 /* body */
271 {
272 const uint64_t *blocks = (const uint64_t *) (data);
273 int i;
274
275 for (i = 0; i < nblocks; i++) {
276 uint64_t k1 = hash_get_block_64(blocks, i*2 + 0);
277 uint64_t k2 = hash_get_block_64(blocks, i*2 + 1);
278
279 k1 *= c1; k1 = hash_rotl_64(k1, 31); k1 *= c2; h1 ^= k1;
280
281 h1 = hash_rotl_64(h1, 27); h1 += h2;
282 h1 = h1*5 + 0x52dce729;
283
284 k2 *= c2; k2 = hash_rotl_64(k2, 33); k2 *= c1; h2 ^= k2;
285
286 h2 = hash_rotl_64(h2, 31); h2 += h1;
287 h2 = h2*5 + 0x38495ab5;
288 }
289 }
290
291 /* tail */
292 {
293 const uint8_t *tail = (const uint8_t*)(data + nblocks*16);
294 uint64_t k1 = 0;
295 uint64_t k2 = 0;
296
297 switch (len & 15) {
298 case 15: k2 ^= ((uint64_t)(tail[14])) << 48;
299 case 14: k2 ^= ((uint64_t)(tail[13])) << 40;
300 case 13: k2 ^= ((uint64_t)(tail[12])) << 32;
301 case 12: k2 ^= ((uint64_t)(tail[11])) << 24;
302 case 11: k2 ^= ((uint64_t)(tail[10])) << 16;
303 case 10: k2 ^= ((uint64_t)(tail[ 9])) << 8;
304 case 9: k2 ^= ((uint64_t)(tail[ 8])) << 0;
305 k2 *= c2; k2 = hash_rotl_64(k2, 33); k2 *= c1; h2 ^= k2;
306
307 case 8: k1 ^= ((uint64_t)(tail[ 7])) << 56;
308 case 7: k1 ^= ((uint64_t)(tail[ 6])) << 48;
309 case 6: k1 ^= ((uint64_t)(tail[ 5])) << 40;
310 case 5: k1 ^= ((uint64_t)(tail[ 4])) << 32;
311 case 4: k1 ^= ((uint64_t)(tail[ 3])) << 24;
312 case 3: k1 ^= ((uint64_t)(tail[ 2])) << 16;
313 case 2: k1 ^= ((uint64_t)(tail[ 1])) << 8;
314 case 1: k1 ^= ((uint64_t)(tail[ 0])) << 0;
315 k1 *= c1; k1 = hash_rotl_64(k1, 31); k1 *= c2; h1 ^= k1;
316 }
317 }
318
319 /* finalization */
320 h1 ^= len; h2 ^= len;
321
322 h1 += h2;
323 h2 += h1;
324
325 h1 = hash_fmix_64(h1);
326 h2 = hash_fmix_64(h2);
327
328 h1 += h2;
329 h2 += h1;
330
331 r_out[0] = h1;
332 r_out[1] = h2;
333 }
334
335 /******************************************************************************/
336 /* API. */
337 JEMALLOC_INLINE void
hash(const void * key,size_t len,const uint32_t seed,size_t r_hash[2])338 hash(const void *key, size_t len, const uint32_t seed, size_t r_hash[2])
339 {
340
341 assert(len <= INT_MAX); /* Unfortunate implementation limitation. */
342
343 #if (LG_SIZEOF_PTR == 3 && !defined(JEMALLOC_BIG_ENDIAN))
344 hash_x64_128(key, (int)len, seed, (uint64_t *)r_hash);
345 #else
346 {
347 uint64_t hashes[2];
348 hash_x86_128(key, (int)len, seed, hashes);
349 r_hash[0] = (size_t)hashes[0];
350 r_hash[1] = (size_t)hashes[1];
351 }
352 #endif
353 }
354 #endif
355
356 #endif /* JEMALLOC_H_INLINES */
357 /******************************************************************************/
358