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
22uint32_t	hash_x86_32(const void *key, int len, uint32_t seed);
23void	hash_x86_128(const void *key, const int len, uint32_t seed,
24    uint64_t r_out[2]);
25void	hash_x64_128(const void *key, const int len, const uint32_t seed,
26    uint64_t r_out[2]);
27void	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. */
34JEMALLOC_INLINE uint32_t
35hash_rotl_32(uint32_t x, int8_t r)
36{
37
38	return ((x << r) | (x >> (32 - r)));
39}
40
41JEMALLOC_INLINE uint64_t
42hash_rotl_64(uint64_t x, int8_t r)
43{
44
45	return ((x << r) | (x >> (64 - r)));
46}
47
48JEMALLOC_INLINE uint32_t
49hash_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
63JEMALLOC_INLINE uint64_t
64hash_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
78JEMALLOC_INLINE uint32_t
79hash_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
91JEMALLOC_INLINE uint64_t
92hash_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
104JEMALLOC_INLINE uint32_t
105hash_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
155UNUSED JEMALLOC_INLINE void
156hash_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
257UNUSED JEMALLOC_INLINE void
258hash_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. */
337JEMALLOC_INLINE void
338hash(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