| 1 | #ifndef FIO_RAND_H |
| 2 | #define FIO_RAND_H |
| 3 | |
| 4 | #include <inttypes.h> |
| 5 | #include <assert.h> |
| 6 | #include "types.h" |
| 7 | |
| 8 | #define FRAND32_MAX (-1U) |
| 9 | #define FRAND64_MAX (-1ULL) |
| 10 | |
| 11 | struct taus88_state { |
| 12 | unsigned int s1, s2, s3; |
| 13 | }; |
| 14 | |
| 15 | struct taus258_state { |
| 16 | uint64_t s1, s2, s3, s4, s5; |
| 17 | }; |
| 18 | |
| 19 | struct frand_state { |
| 20 | unsigned int use64; |
| 21 | union { |
| 22 | struct taus88_state state32; |
| 23 | struct taus258_state state64; |
| 24 | }; |
| 25 | }; |
| 26 | |
| 27 | static inline uint64_t rand_max(struct frand_state *state) |
| 28 | { |
| 29 | if (state->use64) |
| 30 | return FRAND64_MAX; |
| 31 | else |
| 32 | return FRAND32_MAX; |
| 33 | } |
| 34 | |
| 35 | static inline void __frand32_copy(struct taus88_state *dst, |
| 36 | struct taus88_state *src) |
| 37 | { |
| 38 | dst->s1 = src->s1; |
| 39 | dst->s2 = src->s2; |
| 40 | dst->s3 = src->s3; |
| 41 | } |
| 42 | |
| 43 | static inline void __frand64_copy(struct taus258_state *dst, |
| 44 | struct taus258_state *src) |
| 45 | { |
| 46 | dst->s1 = src->s1; |
| 47 | dst->s2 = src->s2; |
| 48 | dst->s3 = src->s3; |
| 49 | dst->s4 = src->s4; |
| 50 | dst->s5 = src->s5; |
| 51 | } |
| 52 | |
| 53 | static inline void frand_copy(struct frand_state *dst, struct frand_state *src) |
| 54 | { |
| 55 | if (src->use64) |
| 56 | __frand64_copy(&dst->state64, &src->state64); |
| 57 | else |
| 58 | __frand32_copy(&dst->state32, &src->state32); |
| 59 | |
| 60 | dst->use64 = src->use64; |
| 61 | } |
| 62 | |
| 63 | static inline unsigned int __rand32(struct taus88_state *state) |
| 64 | { |
| 65 | #define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b) |
| 66 | |
| 67 | state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12); |
| 68 | state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4); |
| 69 | state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17); |
| 70 | |
| 71 | return (state->s1 ^ state->s2 ^ state->s3); |
| 72 | } |
| 73 | |
| 74 | static inline uint64_t __rand64(struct taus258_state *state) |
| 75 | { |
| 76 | uint64_t xval; |
| 77 | |
| 78 | xval = ((state->s1 << 1) ^ state->s1) >> 53; |
| 79 | state->s1 = ((state->s1 & 18446744073709551614ULL) << 10) ^ xval; |
| 80 | |
| 81 | xval = ((state->s2 << 24) ^ state->s2) >> 50; |
| 82 | state->s2 = ((state->s2 & 18446744073709551104ULL) << 5) ^ xval; |
| 83 | |
| 84 | xval = ((state->s3 << 3) ^ state->s3) >> 23; |
| 85 | state->s3 = ((state->s3 & 18446744073709547520ULL) << 29) ^ xval; |
| 86 | |
| 87 | xval = ((state->s4 << 5) ^ state->s4) >> 24; |
| 88 | state->s4 = ((state->s4 & 18446744073709420544ULL) << 23) ^ xval; |
| 89 | |
| 90 | xval = ((state->s5 << 3) ^ state->s5) >> 33; |
| 91 | state->s5 = ((state->s5 & 18446744073701163008ULL) << 8) ^ xval; |
| 92 | |
| 93 | return (state->s1 ^ state->s2 ^ state->s3 ^ state->s4 ^ state->s5); |
| 94 | } |
| 95 | |
| 96 | static inline uint64_t __rand(struct frand_state *state) |
| 97 | { |
| 98 | if (state->use64) |
| 99 | return __rand64(&state->state64); |
| 100 | else |
| 101 | return __rand32(&state->state32); |
| 102 | } |
| 103 | |
| 104 | static inline double __rand_0_1(struct frand_state *state) |
| 105 | { |
| 106 | if (state->use64) { |
| 107 | uint64_t val = __rand64(&state->state64); |
| 108 | |
| 109 | return (val + 1.0) / (FRAND64_MAX + 1.0); |
| 110 | } else { |
| 111 | uint32_t val = __rand32(&state->state32); |
| 112 | |
| 113 | return (val + 1.0) / (FRAND32_MAX + 1.0); |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | /* |
| 118 | * Generate a random value between 'start' and 'end', both inclusive |
| 119 | */ |
| 120 | static inline int rand32_between(struct frand_state *state, int start, int end) |
| 121 | { |
| 122 | uint32_t r; |
| 123 | |
| 124 | assert(!state->use64); |
| 125 | |
| 126 | r = __rand32(&state->state32); |
| 127 | return start + (int) ((double)end * (r / (FRAND32_MAX + 1.0))); |
| 128 | } |
| 129 | |
| 130 | extern void init_rand(struct frand_state *, bool); |
| 131 | extern void init_rand_seed(struct frand_state *, unsigned int seed, bool); |
| 132 | extern void __fill_random_buf(void *buf, unsigned int len, unsigned long seed); |
| 133 | extern unsigned long fill_random_buf(struct frand_state *, void *buf, unsigned int len); |
| 134 | extern void __fill_random_buf_percentage(unsigned long, void *, unsigned int, unsigned int, unsigned int, char *, unsigned int); |
| 135 | extern unsigned long fill_random_buf_percentage(struct frand_state *, void *, unsigned int, unsigned int, unsigned int, char *, unsigned int); |
| 136 | |
| 137 | #endif |