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author | Mitya Selivanov <automainint@guattari.tech> | 2023-12-29 06:21:33 +0100 |
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committer | Mitya Selivanov <automainint@guattari.tech> | 2023-12-29 06:21:33 +0100 |
commit | 2d6c8fec45b23a8a28668ecf3ef281139ab778a7 (patch) | |
tree | 75d2a8538992129a83c0c2b83688289443d697e5 /source/kit/mersenne_twister_64.c | |
parent | 820b171245f2f14766f3accdb0246a4e2c0d596a (diff) | |
download | saw-2d6c8fec45b23a8a28668ecf3ef281139ab778a7.zip |
refactor dependencies; include dependencies source code
Diffstat (limited to 'source/kit/mersenne_twister_64.c')
-rw-r--r-- | source/kit/mersenne_twister_64.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/source/kit/mersenne_twister_64.c b/source/kit/mersenne_twister_64.c new file mode 100644 index 0000000..4032dc9 --- /dev/null +++ b/source/kit/mersenne_twister_64.c @@ -0,0 +1,66 @@ +#include "mersenne_twister_64.h" + +#define MM 156 +#define MATRIX_A 0xb5026f5aa96619e9ull +#define UM 0xffffffff80000000ull +#define LM 0x7fffffffull + +void kit_mt64_init_array(kit_mt64_state_t *state, i64 size, + u64 *seed) { + i64 i; + for (i = 0; i < size && i < KIT_MT64_N; i++) state->mt[i] = seed[i]; + for (state->index = size; state->index < KIT_MT64_N; state->index++) + state->mt[state->index] = (6364136223846793005ull * + (state->mt[state->index - 1] ^ + (state->mt[state->index - 1] >> + 62u)) + + state->index); +} + +void kit_mt64_init(kit_mt64_state_t *state, u64 seed) { + kit_mt64_init_array(state, 1, &seed); +} + +void kit_mt64_rotate(kit_mt64_state_t *state) { + static u64 mag01[2] = { 0ull, MATRIX_A }; + + u64 x; + i32 i; + + for (i = 0; i < KIT_MT64_N - MM; i++) { + x = (state->mt[i] & UM) | (state->mt[i + 1] & LM); + state->mt[i] = state->mt[i + MM] ^ (x >> 1u) ^ + mag01[(i32) (x & 1ull)]; + } + + for (; i < KIT_MT64_N - 1; i++) { + x = (state->mt[i] & UM) | (state->mt[i + 1] & LM); + state->mt[i] = state->mt[i + (MM - KIT_MT64_N)] ^ (x >> 1u) ^ + mag01[(i32) (x & 1ull)]; + } + + x = (state->mt[KIT_MT64_N - 1] & UM) | (state->mt[0] & LM); + state->mt[KIT_MT64_N - 1] = state->mt[MM - 1] ^ (x >> 1u) ^ + mag01[(i32) (x & 1ull)]; + + state->index = 0; +} + +u64 kit_mt64_generate(kit_mt64_state_t *state) { + if (state->index >= KIT_MT64_N) + kit_mt64_rotate(state); + + u64 x = state->mt[state->index++]; + + x ^= (x >> 29u) & 0x5555555555555555ull; + x ^= (x << 17u) & 0x71d67fffeda60000ull; + x ^= (x << 37u) & 0xfff7eee000000000ull; + x ^= (x >> 43u); + + return x; +} + +#undef MM +#undef MATRIX_A +#undef UM +#undef LM |