1//-----------------------------------------------------------------------------
2// MurmurHash3 was written by Austin Appleby, and is placed in the public
3// domain. The author hereby disclaims copyright to this source code.
4
5// Note - The x86 and x64 versions do _not_ produce the same results, as the
6// algorithms are optimized for their respective platforms. You can still
7// compile and run any of them on any platform, but your performance with the
8// non-native version will be less than optimal.
9
10#include "MurmurHash3.h"
11
12//-----------------------------------------------------------------------------
13// Platform-specific functions and macros
14
15// Microsoft Visual Studio
16
17#if defined(_MSC_VER)
18
19#define FORCE_INLINE	__forceinline
20
21#include <stdlib.h>
22
23#define ROTL32(x,y)	_rotl(x,y)
24#define ROTL64(x,y)	_rotl64(x,y)
25
26#define BIG_CONSTANT(x) (x)
27
28// Other compilers
29
30#else	// defined(_MSC_VER)
31
32#define	FORCE_INLINE __attribute__((always_inline))
33
34inline uint32_t rotl32 ( uint32_t x, int8_t r )
35{
36  return (x << r) | (x >> (32 - r));
37}
38
39inline uint64_t rotl64 ( uint64_t x, int8_t r )
40{
41  return (x << r) | (x >> (64 - r));
42}
43
44#define	ROTL32(x,y)	rotl32(x,y)
45#define ROTL64(x,y)	rotl64(x,y)
46
47#define BIG_CONSTANT(x) (x##LLU)
48
49#endif // !defined(_MSC_VER)
50
51//-----------------------------------------------------------------------------
52// Block read - if your platform needs to do endian-swapping or can only
53// handle aligned reads, do the conversion here
54
55FORCE_INLINE uint32_t getblock ( const uint32_t * p, int i )
56{
57  return p[i];
58}
59
60FORCE_INLINE uint64_t getblock ( const uint64_t * p, int i )
61{
62  return p[i];
63}
64
65//-----------------------------------------------------------------------------
66// Finalization mix - force all bits of a hash block to avalanche
67
68FORCE_INLINE uint32_t fmix ( uint32_t h )
69{
70  h ^= h >> 16;
71  h *= 0x85ebca6b;
72  h ^= h >> 13;
73  h *= 0xc2b2ae35;
74  h ^= h >> 16;
75
76  return h;
77}
78
79//----------
80
81FORCE_INLINE uint64_t fmix ( uint64_t k )
82{
83  k ^= k >> 33;
84  k *= BIG_CONSTANT(0xff51afd7ed558ccd);
85  k ^= k >> 33;
86  k *= BIG_CONSTANT(0xc4ceb9fe1a85ec53);
87  k ^= k >> 33;
88
89  return k;
90}
91
92//-----------------------------------------------------------------------------
93
94void MurmurHash3_x86_32 ( const void * key, int len,
95                          uint32_t seed, void * out )
96{
97  const uint8_t * data = (const uint8_t*)key;
98  const int nblocks = len / 4;
99
100  uint32_t h1 = seed;
101
102  const uint32_t c1 = 0xcc9e2d51;
103  const uint32_t c2 = 0x1b873593;
104
105  //----------
106  // body
107
108  const uint32_t * blocks = (const uint32_t *)(data + nblocks*4);
109
110  for(int i = -nblocks; i; i++)
111  {
112    uint32_t k1 = getblock(blocks,i);
113
114    k1 *= c1;
115    k1 = ROTL32(k1,15);
116    k1 *= c2;
117
118    h1 ^= k1;
119    h1 = ROTL32(h1,13);
120    h1 = h1*5+0xe6546b64;
121  }
122
123  //----------
124  // tail
125
126  const uint8_t * tail = (const uint8_t*)(data + nblocks*4);
127
128  uint32_t k1 = 0;
129
130  switch(len & 3)
131  {
132  case 3: k1 ^= tail[2] << 16;
133  case 2: k1 ^= tail[1] << 8;
134  case 1: k1 ^= tail[0];
135          k1 *= c1; k1 = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
136  };
137
138  //----------
139  // finalization
140
141  h1 ^= len;
142
143  h1 = fmix(h1);
144
145  *(uint32_t*)out = h1;
146}
147
148//-----------------------------------------------------------------------------
149
150void MurmurHash3_x86_128 ( const void * key, const int len,
151                           uint32_t seed, void * out )
152{
153  const uint8_t * data = (const uint8_t*)key;
154  const int nblocks = len / 16;
155
156  uint32_t h1 = seed;
157  uint32_t h2 = seed;
158  uint32_t h3 = seed;
159  uint32_t h4 = seed;
160
161  const uint32_t c1 = 0x239b961b;
162  const uint32_t c2 = 0xab0e9789;
163  const uint32_t c3 = 0x38b34ae5;
164  const uint32_t c4 = 0xa1e38b93;
165
166  //----------
167  // body
168
169  const uint32_t * blocks = (const uint32_t *)(data + nblocks*16);
170
171  for(int i = -nblocks; i; i++)
172  {
173    uint32_t k1 = getblock(blocks,i*4+0);
174    uint32_t k2 = getblock(blocks,i*4+1);
175    uint32_t k3 = getblock(blocks,i*4+2);
176    uint32_t k4 = getblock(blocks,i*4+3);
177
178    k1 *= c1; k1  = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
179
180    h1 = ROTL32(h1,19); h1 += h2; h1 = h1*5+0x561ccd1b;
181
182    k2 *= c2; k2  = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
183
184    h2 = ROTL32(h2,17); h2 += h3; h2 = h2*5+0x0bcaa747;
185
186    k3 *= c3; k3  = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
187
188    h3 = ROTL32(h3,15); h3 += h4; h3 = h3*5+0x96cd1c35;
189
190    k4 *= c4; k4  = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
191
192    h4 = ROTL32(h4,13); h4 += h1; h4 = h4*5+0x32ac3b17;
193  }
194
195  //----------
196  // tail
197
198  const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
199
200  uint32_t k1 = 0;
201  uint32_t k2 = 0;
202  uint32_t k3 = 0;
203  uint32_t k4 = 0;
204
205  switch(len & 15)
206  {
207  case 15: k4 ^= tail[14] << 16;
208  case 14: k4 ^= tail[13] << 8;
209  case 13: k4 ^= tail[12] << 0;
210           k4 *= c4; k4  = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
211
212  case 12: k3 ^= tail[11] << 24;
213  case 11: k3 ^= tail[10] << 16;
214  case 10: k3 ^= tail[ 9] << 8;
215  case  9: k3 ^= tail[ 8] << 0;
216           k3 *= c3; k3  = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
217
218  case  8: k2 ^= tail[ 7] << 24;
219  case  7: k2 ^= tail[ 6] << 16;
220  case  6: k2 ^= tail[ 5] << 8;
221  case  5: k2 ^= tail[ 4] << 0;
222           k2 *= c2; k2  = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
223
224  case  4: k1 ^= tail[ 3] << 24;
225  case  3: k1 ^= tail[ 2] << 16;
226  case  2: k1 ^= tail[ 1] << 8;
227  case  1: k1 ^= tail[ 0] << 0;
228           k1 *= c1; k1  = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
229  };
230
231  //----------
232  // finalization
233
234  h1 ^= len; h2 ^= len; h3 ^= len; h4 ^= len;
235
236  h1 += h2; h1 += h3; h1 += h4;
237  h2 += h1; h3 += h1; h4 += h1;
238
239  h1 = fmix(h1);
240  h2 = fmix(h2);
241  h3 = fmix(h3);
242  h4 = fmix(h4);
243
244  h1 += h2; h1 += h3; h1 += h4;
245  h2 += h1; h3 += h1; h4 += h1;
246
247  ((uint32_t*)out)[0] = h1;
248  ((uint32_t*)out)[1] = h2;
249  ((uint32_t*)out)[2] = h3;
250  ((uint32_t*)out)[3] = h4;
251}
252
253//-----------------------------------------------------------------------------
254
255void MurmurHash3_x64_128 ( const void * key, const int len,
256                           const uint32_t seed, void * out )
257{
258  const uint8_t * data = (const uint8_t*)key;
259  const int nblocks = len / 16;
260
261  uint64_t h1 = seed;
262  uint64_t h2 = seed;
263
264  const uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
265  const uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);
266
267  //----------
268  // body
269
270  const uint64_t * blocks = (const uint64_t *)(data);
271
272  for(int i = 0; i < nblocks; i++)
273  {
274    uint64_t k1 = getblock(blocks,i*2+0);
275    uint64_t k2 = getblock(blocks,i*2+1);
276
277    k1 *= c1; k1  = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
278
279    h1 = ROTL64(h1,27); h1 += h2; h1 = h1*5+0x52dce729;
280
281    k2 *= c2; k2  = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
282
283    h2 = ROTL64(h2,31); h2 += h1; h2 = h2*5+0x38495ab5;
284  }
285
286  //----------
287  // tail
288
289  const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
290
291  uint64_t k1 = 0;
292  uint64_t k2 = 0;
293
294  switch(len & 15)
295  {
296  case 15: k2 ^= uint64_t(tail[14]) << 48;
297  case 14: k2 ^= uint64_t(tail[13]) << 40;
298  case 13: k2 ^= uint64_t(tail[12]) << 32;
299  case 12: k2 ^= uint64_t(tail[11]) << 24;
300  case 11: k2 ^= uint64_t(tail[10]) << 16;
301  case 10: k2 ^= uint64_t(tail[ 9]) << 8;
302  case  9: k2 ^= uint64_t(tail[ 8]) << 0;
303           k2 *= c2; k2  = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
304
305  case  8: k1 ^= uint64_t(tail[ 7]) << 56;
306  case  7: k1 ^= uint64_t(tail[ 6]) << 48;
307  case  6: k1 ^= uint64_t(tail[ 5]) << 40;
308  case  5: k1 ^= uint64_t(tail[ 4]) << 32;
309  case  4: k1 ^= uint64_t(tail[ 3]) << 24;
310  case  3: k1 ^= uint64_t(tail[ 2]) << 16;
311  case  2: k1 ^= uint64_t(tail[ 1]) << 8;
312  case  1: k1 ^= uint64_t(tail[ 0]) << 0;
313           k1 *= c1; k1  = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
314  };
315
316  //----------
317  // finalization
318
319  h1 ^= len; h2 ^= len;
320
321  h1 += h2;
322  h2 += h1;
323
324  h1 = fmix(h1);
325  h2 = fmix(h2);
326
327  h1 += h2;
328  h2 += h1;
329
330  ((uint64_t*)out)[0] = h1;
331  ((uint64_t*)out)[1] = h2;
332}
333
334//-----------------------------------------------------------------------------
335