1 | #pragma once |
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2 | |
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3 | #include <stdint.h> |
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4 | |
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5 | // Pipelined to allow out-of-order overlap with reduced dependencies. Critically, return the current value, and compute |
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6 | // and store the next value. |
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7 | |
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8 | //-------------------------------------------------- |
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9 | #if defined(__SIZEOF_INT128__) |
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10 | static inline uint64_t lehmer64( __uint128_t & state ) { |
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11 | __uint128_t ret = state; |
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12 | state *= 0xda942042e4dd58b5; |
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13 | return ret >> 64; |
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14 | } |
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15 | |
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16 | //-------------------------------------------------- |
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17 | static inline uint64_t wyhash64( uint64_t & state ) { |
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18 | state += 0x60bee2bee120fc15; |
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19 | __uint128_t tmp; |
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20 | tmp = (__uint128_t) state * 0xa3b195354a39b70d; |
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21 | uint64_t m1 = (tmp >> 64) ^ tmp; |
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22 | tmp = (__uint128_t)m1 * 0x1b03738712fad5c9; |
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23 | uint64_t m2 = (tmp >> 64) ^ tmp; |
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24 | return m2; |
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25 | } |
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26 | #endif |
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27 | |
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28 | //-------------------------------------------------- |
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29 | static inline uint64_t xorshift_13_7_17( uint64_t & state ) { |
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30 | uint64_t ret = state; |
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31 | state ^= state << 13; |
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32 | state ^= state >> 7; |
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33 | state ^= state << 17; |
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34 | return ret; |
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35 | } |
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36 | |
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37 | //-------------------------------------------------- |
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38 | static inline uint32_t xorshift_6_21_7( uint32_t & state ) { |
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39 | uint32_t ret = state; |
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40 | state ^= state << 6; |
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41 | state ^= state >> 21; |
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42 | state ^= state << 7; |
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43 | return ret; |
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44 | } // xorshift_6_21_7 |
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45 | |
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46 | //-------------------------------------------------- |
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47 | typedef struct { |
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48 | uint32_t a, b, c, d; |
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49 | uint32_t counter; |
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50 | } xorwow__state_t; |
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51 | |
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52 | /* The state array must be initialized to not be all zero in the first four words */ |
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53 | static inline uint32_t xorwow( xorwow__state_t & state ) { |
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54 | /* Algorithm "xorwow" from p. 5 of Marsaglia, "Xorshift RNGs" */ |
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55 | uint32_t ret = state.a + state.counter; |
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56 | uint32_t t = state.d; |
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57 | |
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58 | uint32_t const s = state.a; |
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59 | state.d = state.c; |
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60 | state.c = state.b; |
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61 | state.b = s; |
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62 | |
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63 | t ^= t >> 2; |
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64 | t ^= t << 1; |
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65 | t ^= s ^ (s << 4); |
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66 | state.a = t; |
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67 | |
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68 | state.counter += 362437; |
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69 | return ret; |
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70 | } |
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71 | |
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72 | //-------------------------------------------------- |
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73 | static inline uint32_t LCG( uint32_t & state ) { // linear congruential generator |
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74 | uint32_t ret = state; |
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75 | state = 36969 * (state & 65535) + (state >> 16); // 36969 is NOT prime! No not change it! |
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76 | return ret; |
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77 | } // LCG |
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78 | |
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79 | //-------------------------------------------------- |
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80 | #define M (1_l64u << 48_l64u) |
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81 | #define A (25214903917_l64u) |
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82 | #define AI (18446708753438544741_l64u) |
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83 | #define C (11_l64u) |
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84 | #define D (16_l64u) |
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85 | |
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86 | static inline uint32_t LCGBI_fwd( uint64_t & state ) { |
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87 | state = (A * state + C) & (M - 1); |
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88 | return state >> D; |
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89 | } |
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90 | |
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91 | static inline uint32_t LCGBI_bck( uint64_t & state ) { |
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92 | unsigned int r = state >> D; |
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93 | state = AI * (state - C) & (M - 1); |
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94 | return r; |
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95 | } |
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96 | |
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97 | #undef M |
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98 | #undef A |
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99 | #undef AI |
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100 | #undef C |
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101 | #undef D |
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