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Diffstat (limited to 'src/haversine/libs/pcg/pcg-rngs-32.c')
| -rw-r--r-- | src/haversine/libs/pcg/pcg-rngs-32.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/haversine/libs/pcg/pcg-rngs-32.c b/src/haversine/libs/pcg/pcg-rngs-32.c new file mode 100644 index 0000000..1c8da7e --- /dev/null +++ b/src/haversine/libs/pcg/pcg-rngs-32.c @@ -0,0 +1,187 @@ +/* + * 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. + */ + +extern inline void pcg_oneseq_32_step_r(struct pcg_state_32* rng); + +extern inline void pcg_oneseq_32_advance_r(struct pcg_state_32* rng, + uint32_t delta); + +extern inline void pcg_mcg_32_step_r(struct pcg_state_32* rng); + +extern inline void pcg_mcg_32_advance_r(struct pcg_state_32* rng, + uint32_t delta); + +extern inline void pcg_unique_32_step_r(struct pcg_state_32* rng); + +extern inline void pcg_unique_32_advance_r(struct pcg_state_32* rng, + uint32_t delta); + +extern inline void pcg_setseq_32_step_r(struct pcg_state_setseq_32* rng); + +extern inline void pcg_setseq_32_advance_r(struct pcg_state_setseq_32* rng, + uint32_t delta); + +/* 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. + */ + +extern inline void pcg_oneseq_32_srandom_r(struct pcg_state_32* rng, + uint32_t initstate); + +extern inline void pcg_mcg_32_srandom_r(struct pcg_state_32* rng, + uint32_t initstate); + +extern inline void pcg_unique_32_srandom_r(struct pcg_state_32* rng, + uint32_t initstate); + +extern inline void pcg_setseq_32_srandom_r(struct pcg_state_setseq_32* rng, + uint32_t initstate, + uint32_t initseq); + +/* 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 */ + +extern inline uint16_t +pcg_oneseq_32_xsh_rs_16_random_r(struct pcg_state_32* rng); + +extern inline uint16_t +pcg_oneseq_32_xsh_rs_16_boundedrand_r(struct pcg_state_32* rng, uint16_t bound); + +extern inline uint16_t +pcg_unique_32_xsh_rs_16_random_r(struct pcg_state_32* rng); + +extern inline uint16_t +pcg_unique_32_xsh_rs_16_boundedrand_r(struct pcg_state_32* rng, uint16_t bound); + +extern inline uint16_t +pcg_setseq_32_xsh_rs_16_random_r(struct pcg_state_setseq_32* rng); + +extern inline uint16_t +pcg_setseq_32_xsh_rs_16_boundedrand_r(struct pcg_state_setseq_32* rng, + uint16_t bound); + +extern inline uint16_t pcg_mcg_32_xsh_rs_16_random_r(struct pcg_state_32* rng); + +extern inline uint16_t +pcg_mcg_32_xsh_rs_16_boundedrand_r(struct pcg_state_32* rng, uint16_t bound); + +/* Generation functions for XSH RR */ + +extern inline uint16_t +pcg_oneseq_32_xsh_rr_16_random_r(struct pcg_state_32* rng); + +extern inline uint16_t +pcg_oneseq_32_xsh_rr_16_boundedrand_r(struct pcg_state_32* rng, uint16_t bound); + +extern inline uint16_t +pcg_unique_32_xsh_rr_16_random_r(struct pcg_state_32* rng); + +extern inline uint16_t +pcg_unique_32_xsh_rr_16_boundedrand_r(struct pcg_state_32* rng, uint16_t bound); + +extern inline uint16_t +pcg_setseq_32_xsh_rr_16_random_r(struct pcg_state_setseq_32* rng); + +extern inline uint16_t +pcg_setseq_32_xsh_rr_16_boundedrand_r(struct pcg_state_setseq_32* rng, + uint16_t bound); + +extern inline uint16_t pcg_mcg_32_xsh_rr_16_random_r(struct pcg_state_32* rng); + +extern inline uint16_t +pcg_mcg_32_xsh_rr_16_boundedrand_r(struct pcg_state_32* rng, uint16_t bound); + +/* Generation functions for RXS M XS (no MCG versions because they + * don't make sense when you want to use the entire state) + */ + +extern inline uint32_t +pcg_oneseq_32_rxs_m_xs_32_random_r(struct pcg_state_32* rng); + +extern inline uint32_t +pcg_oneseq_32_rxs_m_xs_32_boundedrand_r(struct pcg_state_32* rng, + uint32_t bound); + +extern inline uint32_t +pcg_unique_32_rxs_m_xs_32_random_r(struct pcg_state_32* rng); + +extern inline uint32_t +pcg_unique_32_rxs_m_xs_32_boundedrand_r(struct pcg_state_32* rng, + uint32_t bound); + +extern inline uint32_t +pcg_setseq_32_rxs_m_xs_32_random_r(struct pcg_state_setseq_32* rng); + +extern inline uint32_t +pcg_setseq_32_rxs_m_xs_32_boundedrand_r(struct pcg_state_setseq_32* rng, + uint32_t bound); + +/* Generation functions for XSL RR (only defined for "large" types) */ + +/* Generation functions for XSL RR RR (only defined for "large" types) */ + |