[13c5e19] | 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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[611f29d] | 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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[13c5e19] | 8 | //-------------------------------------------------- |
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[7812a7b5] | 9 | #if defined(__SIZEOF_INT128__) |
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[611f29d] | 10 | static inline uint64_t lehmer64( __uint128_t & state ) { |
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| 11 | __uint128_t ret = state; |
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[7812a7b5] | 12 | state *= 0xda942042e4dd58b5; |
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[611f29d] | 13 | return ret >> 64; |
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[7812a7b5] | 14 | } |
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[13c5e19] | 15 | |
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| 16 | //-------------------------------------------------- |
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[611f29d] | 17 | static inline uint64_t wyhash64( uint64_t & state ) { |
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[7812a7b5] | 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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[13c5e19] | 27 | |
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| 28 | //-------------------------------------------------- |
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[611f29d] | 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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[13c5e19] | 35 | } |
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| 36 | |
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[611f29d] | 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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[13c5e19] | 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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[611f29d] | 50 | } xorwow__state_t; |
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[13c5e19] | 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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[611f29d] | 53 | static inline uint32_t xorwow( xorwow__state_t & state ) { |
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[13c5e19] | 54 | /* Algorithm "xorwow" from p. 5 of Marsaglia, "Xorshift RNGs" */ |
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[611f29d] | 55 | uint32_t ret = state.a + state.counter; |
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[13c5e19] | 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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[611f29d] | 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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[4177592f] | 89 | } |
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[611f29d] | 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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