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		/* ANDROID change */
57		memcpy(&ret, (uint8_t*)(p+i), sizeof(uint32_t));
58		/* End ANDROID change */
59		return (ret);
60	}
61
62	return (p[i]);
63}
64
65JEMALLOC_INLINE uint64_t
66hash_get_block_64(const uint64_t *p, int i)
67{
68
69	/* Handle unaligned read. */
70	if (unlikely((uintptr_t)p & (sizeof(uint64_t)-1)) != 0) {
71		uint64_t ret;
72
73		/* ANDROID change */
74		memcpy(&ret, (uint8_t*)(p+i), sizeof(uint64_t));
75		/* End ANDROID change */
76		return (ret);
77	}
78
79	return (p[i]);
80}
81
82JEMALLOC_INLINE uint32_t
83hash_fmix_32(uint32_t h)
84{
85
86	h ^= h >> 16;
87	h *= 0x85ebca6b;
88	h ^= h >> 13;
89	h *= 0xc2b2ae35;
90	h ^= h >> 16;
91
92	return (h);
93}
94
95JEMALLOC_INLINE uint64_t
96hash_fmix_64(uint64_t k)
97{
98
99	k ^= k >> 33;
100	k *= KQU(0xff51afd7ed558ccd);
101	k ^= k >> 33;
102	k *= KQU(0xc4ceb9fe1a85ec53);
103	k ^= k >> 33;
104
105	return (k);
106}
107
108JEMALLOC_INLINE uint32_t
109hash_x86_32(const void *key, int len, uint32_t seed)
110{
111	const uint8_t *data = (const uint8_t *) key;
112	const int nblocks = len / 4;
113
114	uint32_t h1 = seed;
115
116	const uint32_t c1 = 0xcc9e2d51;
117	const uint32_t c2 = 0x1b873593;
118
119	/* body */
120	{
121		const uint32_t *blocks = (const uint32_t *) (data + nblocks*4);
122		int i;
123
124		for (i = -nblocks; i; i++) {
125			uint32_t k1 = hash_get_block_32(blocks, i);
126
127			k1 *= c1;
128			k1 = hash_rotl_32(k1, 15);
129			k1 *= c2;
130
131			h1 ^= k1;
132			h1 = hash_rotl_32(h1, 13);
133			h1 = h1*5 + 0xe6546b64;
134		}
135	}
136
137	/* tail */
138	{
139		const uint8_t *tail = (const uint8_t *) (data + nblocks*4);
140
141		uint32_t k1 = 0;
142
143		switch (len & 3) {
144		case 3: k1 ^= tail[2] << 16;
145		case 2: k1 ^= tail[1] << 8;
146		case 1: k1 ^= tail[0]; k1 *= c1; k1 = hash_rotl_32(k1, 15);
147			k1 *= c2; h1 ^= k1;
148		}
149	}
150
151	/* finalization */
152	h1 ^= len;
153
154	h1 = hash_fmix_32(h1);
155
156	return (h1);
157}
158
159UNUSED JEMALLOC_INLINE void
160hash_x86_128(const void *key, const int len, uint32_t seed,
161    uint64_t r_out[2])
162{
163	const uint8_t * data = (const uint8_t *) key;
164	const int nblocks = len / 16;
165
166	uint32_t h1 = seed;
167	uint32_t h2 = seed;
168	uint32_t h3 = seed;
169	uint32_t h4 = seed;
170
171	const uint32_t c1 = 0x239b961b;
172	const uint32_t c2 = 0xab0e9789;
173	const uint32_t c3 = 0x38b34ae5;
174	const uint32_t c4 = 0xa1e38b93;
175
176	/* body */
177	{
178		const uint32_t *blocks = (const uint32_t *) (data + nblocks*16);
179		int i;
180
181		for (i = -nblocks; i; i++) {
182			uint32_t k1 = hash_get_block_32(blocks, i*4 + 0);
183			uint32_t k2 = hash_get_block_32(blocks, i*4 + 1);
184			uint32_t k3 = hash_get_block_32(blocks, i*4 + 2);
185			uint32_t k4 = hash_get_block_32(blocks, i*4 + 3);
186
187			k1 *= c1; k1 = hash_rotl_32(k1, 15); k1 *= c2; h1 ^= k1;
188
189			h1 = hash_rotl_32(h1, 19); h1 += h2;
190			h1 = h1*5 + 0x561ccd1b;
191
192			k2 *= c2; k2 = hash_rotl_32(k2, 16); k2 *= c3; h2 ^= k2;
193
194			h2 = hash_rotl_32(h2, 17); h2 += h3;
195			h2 = h2*5 + 0x0bcaa747;
196
197			k3 *= c3; k3 = hash_rotl_32(k3, 17); k3 *= c4; h3 ^= k3;
198
199			h3 = hash_rotl_32(h3, 15); h3 += h4;
200			h3 = h3*5 + 0x96cd1c35;
201
202			k4 *= c4; k4 = hash_rotl_32(k4, 18); k4 *= c1; h4 ^= k4;
203
204			h4 = hash_rotl_32(h4, 13); h4 += h1;
205			h4 = h4*5 + 0x32ac3b17;
206		}
207	}
208
209	/* tail */
210	{
211		const uint8_t *tail = (const uint8_t *) (data + nblocks*16);
212		uint32_t k1 = 0;
213		uint32_t k2 = 0;
214		uint32_t k3 = 0;
215		uint32_t k4 = 0;
216
217		switch (len & 15) {
218		case 15: k4 ^= tail[14] << 16;
219		case 14: k4 ^= tail[13] << 8;
220		case 13: k4 ^= tail[12] << 0;
221			k4 *= c4; k4 = hash_rotl_32(k4, 18); k4 *= c1; h4 ^= k4;
222
223		case 12: k3 ^= tail[11] << 24;
224		case 11: k3 ^= tail[10] << 16;
225		case 10: k3 ^= tail[ 9] << 8;
226		case  9: k3 ^= tail[ 8] << 0;
227		     k3 *= c3; k3 = hash_rotl_32(k3, 17); k3 *= c4; h3 ^= k3;
228
229		case  8: k2 ^= tail[ 7] << 24;
230		case  7: k2 ^= tail[ 6] << 16;
231		case  6: k2 ^= tail[ 5] << 8;
232		case  5: k2 ^= tail[ 4] << 0;
233			k2 *= c2; k2 = hash_rotl_32(k2, 16); k2 *= c3; h2 ^= k2;
234
235		case  4: k1 ^= tail[ 3] << 24;
236		case  3: k1 ^= tail[ 2] << 16;
237		case  2: k1 ^= tail[ 1] << 8;
238		case  1: k1 ^= tail[ 0] << 0;
239			k1 *= c1; k1 = hash_rotl_32(k1, 15); k1 *= c2; h1 ^= k1;
240		}
241	}
242
243	/* finalization */
244	h1 ^= len; h2 ^= len; h3 ^= len; h4 ^= len;
245
246	h1 += h2; h1 += h3; h1 += h4;
247	h2 += h1; h3 += h1; h4 += h1;
248
249	h1 = hash_fmix_32(h1);
250	h2 = hash_fmix_32(h2);
251	h3 = hash_fmix_32(h3);
252	h4 = hash_fmix_32(h4);
253
254	h1 += h2; h1 += h3; h1 += h4;
255	h2 += h1; h3 += h1; h4 += h1;
256
257	r_out[0] = (((uint64_t) h2) << 32) | h1;
258	r_out[1] = (((uint64_t) h4) << 32) | h3;
259}
260
261UNUSED JEMALLOC_INLINE void
262hash_x64_128(const void *key, const int len, const uint32_t seed,
263    uint64_t r_out[2])
264{
265	const uint8_t *data = (const uint8_t *) key;
266	const int nblocks = len / 16;
267
268	uint64_t h1 = seed;
269	uint64_t h2 = seed;
270
271	const uint64_t c1 = KQU(0x87c37b91114253d5);
272	const uint64_t c2 = KQU(0x4cf5ad432745937f);
273
274	/* body */
275	{
276		const uint64_t *blocks = (const uint64_t *) (data);
277		int i;
278
279		for (i = 0; i < nblocks; i++) {
280			uint64_t k1 = hash_get_block_64(blocks, i*2 + 0);
281			uint64_t k2 = hash_get_block_64(blocks, i*2 + 1);
282
283			k1 *= c1; k1 = hash_rotl_64(k1, 31); k1 *= c2; h1 ^= k1;
284
285			h1 = hash_rotl_64(h1, 27); h1 += h2;
286			h1 = h1*5 + 0x52dce729;
287
288			k2 *= c2; k2 = hash_rotl_64(k2, 33); k2 *= c1; h2 ^= k2;
289
290			h2 = hash_rotl_64(h2, 31); h2 += h1;
291			h2 = h2*5 + 0x38495ab5;
292		}
293	}
294
295	/* tail */
296	{
297		const uint8_t *tail = (const uint8_t*)(data + nblocks*16);
298		uint64_t k1 = 0;
299		uint64_t k2 = 0;
300
301		switch (len & 15) {
302		case 15: k2 ^= ((uint64_t)(tail[14])) << 48;
303		case 14: k2 ^= ((uint64_t)(tail[13])) << 40;
304		case 13: k2 ^= ((uint64_t)(tail[12])) << 32;
305		case 12: k2 ^= ((uint64_t)(tail[11])) << 24;
306		case 11: k2 ^= ((uint64_t)(tail[10])) << 16;
307		case 10: k2 ^= ((uint64_t)(tail[ 9])) << 8;
308		case  9: k2 ^= ((uint64_t)(tail[ 8])) << 0;
309			k2 *= c2; k2 = hash_rotl_64(k2, 33); k2 *= c1; h2 ^= k2;
310
311		case  8: k1 ^= ((uint64_t)(tail[ 7])) << 56;
312		case  7: k1 ^= ((uint64_t)(tail[ 6])) << 48;
313		case  6: k1 ^= ((uint64_t)(tail[ 5])) << 40;
314		case  5: k1 ^= ((uint64_t)(tail[ 4])) << 32;
315		case  4: k1 ^= ((uint64_t)(tail[ 3])) << 24;
316		case  3: k1 ^= ((uint64_t)(tail[ 2])) << 16;
317		case  2: k1 ^= ((uint64_t)(tail[ 1])) << 8;
318		case  1: k1 ^= ((uint64_t)(tail[ 0])) << 0;
319			k1 *= c1; k1 = hash_rotl_64(k1, 31); k1 *= c2; h1 ^= k1;
320		}
321	}
322
323	/* finalization */
324	h1 ^= len; h2 ^= len;
325
326	h1 += h2;
327	h2 += h1;
328
329	h1 = hash_fmix_64(h1);
330	h2 = hash_fmix_64(h2);
331
332	h1 += h2;
333	h2 += h1;
334
335	r_out[0] = h1;
336	r_out[1] = h2;
337}
338
339/******************************************************************************/
340/* API. */
341JEMALLOC_INLINE void
342hash(const void *key, size_t len, const uint32_t seed, size_t r_hash[2])
343{
344
345	assert(len <= INT_MAX); /* Unfortunate implementation limitation. */
346
347#if (LG_SIZEOF_PTR == 3 && !defined(JEMALLOC_BIG_ENDIAN))
348	hash_x64_128(key, (int)len, seed, (uint64_t *)r_hash);
349#else
350	{
351		uint64_t hashes[2];
352		hash_x86_128(key, (int)len, seed, hashes);
353		r_hash[0] = (size_t)hashes[0];
354		r_hash[1] = (size_t)hashes[1];
355	}
356#endif
357}
358#endif
359
360#endif /* JEMALLOC_H_INLINES */
361/******************************************************************************/
362