summaryrefslogtreecommitdiff
path: root/src/haversine/libs/pcg/pcg-rngs-128.c
blob: 8023589580728e31344a76dd7465d5410abf21f9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
/*
 * PCG Random Number Generation for C.
 *
 * Copyright 2014 Melissa O'Neill <oneill@pcg-random.org>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * For additional information about the PCG random number generation scheme,
 * including its license and other licensing options, visit
 *
 *       http://www.pcg-random.org
 */
 
/* 
 * This code is derived from the canonical C++ PCG implementation, which
 * has many additional features and is preferable if you can use C++ in
 * your project.
 *
 * The contents of this file were mechanically derived from pcg_variants.h
 * (every inline function defined there gets an exern declaration here).
 */

#include "pcg_variants.h"

/* Functions to advance the underlying LCG, one version for each size and
 * each style.  These functions are considered semi-private.  There is rarely
 * a good reason to call them directly.
 */

#if PCG_HAS_128BIT_OPS
extern inline void pcg_oneseq_128_step_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_oneseq_128_advance_r(struct pcg_state_128* rng,
                                            pcg128_t delta);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_mcg_128_step_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_mcg_128_advance_r(struct pcg_state_128* rng,
                                         pcg128_t delta);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_unique_128_step_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_unique_128_advance_r(struct pcg_state_128* rng,
                                            pcg128_t delta);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_setseq_128_step_r(struct pcg_state_setseq_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_setseq_128_advance_r(struct pcg_state_setseq_128* rng,
                                            pcg128_t delta);
#endif

/* Functions to seed the RNG state, one version for each size and each
 * style.  Unlike the step functions, regular users can and should call
 * these functions.
 */

#if PCG_HAS_128BIT_OPS
extern inline void pcg_oneseq_128_srandom_r(struct pcg_state_128* rng,
                                            pcg128_t initstate);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_mcg_128_srandom_r(struct pcg_state_128* rng,
                                         pcg128_t initstate);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_unique_128_srandom_r(struct pcg_state_128* rng,
                                            pcg128_t initstate);
#endif

#if PCG_HAS_128BIT_OPS
extern inline void pcg_setseq_128_srandom_r(struct pcg_state_setseq_128* rng,
                                            pcg128_t initstate,
                                            pcg128_t initseq);
#endif

/* Now, finally we create each of the individual generators. We provide
 * a random_r function that provides a random number of the appropriate
 * type (using the full range of the type) and a boundedrand_r version
 * that provides
 *
 * Implementation notes for boundedrand_r:
 *
 *     To avoid bias, we need to make the range of the RNG a multiple of
 *     bound, which we do by dropping output less than a threshold.
 *     Let's consider a 32-bit case...  A naive scheme to calculate the
 *     threshold would be to do
 *
 *         uint32_t threshold = 0x100000000ull % bound;
 *
 *     but 64-bit div/mod is slower than 32-bit div/mod (especially on
 *     32-bit platforms).  In essence, we do
 *
 *         uint32_t threshold = (0x100000000ull-bound) % bound;
 *
 *     because this version will calculate the same modulus, but the LHS
 *     value is less than 2^32.
 *
 *     (Note that using modulo is only wise for good RNGs, poorer RNGs
 *     such as raw LCGs do better using a technique based on division.)
 *     Empricical tests show that division is preferable to modulus for
 *     reducting the range of an RNG.  It's faster, and sometimes it can
 *     even be statistically prefereable.
 */

/* Generation functions for XSH RS */

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_oneseq_128_xsh_rs_64_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_oneseq_128_xsh_rs_64_boundedrand_r(struct pcg_state_128* rng,
                                       uint64_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_unique_128_xsh_rs_64_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_unique_128_xsh_rs_64_boundedrand_r(struct pcg_state_128* rng,
                                       uint64_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_setseq_128_xsh_rs_64_random_r(struct pcg_state_setseq_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_setseq_128_xsh_rs_64_boundedrand_r(struct pcg_state_setseq_128* rng,
                                       uint64_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_mcg_128_xsh_rs_64_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_mcg_128_xsh_rs_64_boundedrand_r(struct pcg_state_128* rng, uint64_t bound);
#endif

/* Generation functions for XSH RR */

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_oneseq_128_xsh_rr_64_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_oneseq_128_xsh_rr_64_boundedrand_r(struct pcg_state_128* rng,
                                       uint64_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_unique_128_xsh_rr_64_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_unique_128_xsh_rr_64_boundedrand_r(struct pcg_state_128* rng,
                                       uint64_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_setseq_128_xsh_rr_64_random_r(struct pcg_state_setseq_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_setseq_128_xsh_rr_64_boundedrand_r(struct pcg_state_setseq_128* rng,
                                       uint64_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_mcg_128_xsh_rr_64_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_mcg_128_xsh_rr_64_boundedrand_r(struct pcg_state_128* rng, uint64_t bound);
#endif

/* Generation functions for RXS M XS (no MCG versions because they
 * don't make sense when you want to use the entire state)
 */

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_oneseq_128_rxs_m_xs_128_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_oneseq_128_rxs_m_xs_128_boundedrand_r(struct pcg_state_128* rng,
                                          pcg128_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_unique_128_rxs_m_xs_128_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_unique_128_rxs_m_xs_128_boundedrand_r(struct pcg_state_128* rng,
                                          pcg128_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_setseq_128_rxs_m_xs_128_random_r(struct pcg_state_setseq_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_setseq_128_rxs_m_xs_128_boundedrand_r(struct pcg_state_setseq_128* rng,
                                          pcg128_t bound);
#endif

/* Generation functions for XSL RR (only defined for "large" types) */

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_oneseq_128_xsl_rr_64_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_oneseq_128_xsl_rr_64_boundedrand_r(struct pcg_state_128* rng,
                                       uint64_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_unique_128_xsl_rr_64_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_unique_128_xsl_rr_64_boundedrand_r(struct pcg_state_128* rng,
                                       uint64_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_setseq_128_xsl_rr_64_random_r(struct pcg_state_setseq_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_setseq_128_xsl_rr_64_boundedrand_r(struct pcg_state_setseq_128* rng,
                                       uint64_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_mcg_128_xsl_rr_64_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline uint64_t
pcg_mcg_128_xsl_rr_64_boundedrand_r(struct pcg_state_128* rng, uint64_t bound);
#endif

/* Generation functions for XSL RR RR (only defined for "large" types) */

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_oneseq_128_xsl_rr_rr_128_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_oneseq_128_xsl_rr_rr_128_boundedrand_r(struct pcg_state_128* rng,
                                           pcg128_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_unique_128_xsl_rr_rr_128_random_r(struct pcg_state_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_unique_128_xsl_rr_rr_128_boundedrand_r(struct pcg_state_128* rng,
                                           pcg128_t bound);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_setseq_128_xsl_rr_rr_128_random_r(struct pcg_state_setseq_128* rng);
#endif

#if PCG_HAS_128BIT_OPS
extern inline pcg128_t
pcg_setseq_128_xsl_rr_rr_128_boundedrand_r(struct pcg_state_setseq_128* rng,
                                           pcg128_t bound);
#endif