1 #ifndef FIO_RAND_H
2 #define FIO_RAND_H
3
4 #include <inttypes.h>
5 #include <assert.h>
6 #include "types.h"
7 #include "../arch/arch.h"
8
9 #define FRAND32_MAX (-1U)
10 #define FRAND64_MAX (-1ULL)
11
12 struct taus88_state {
13 unsigned int s1, s2, s3;
14 };
15
16 struct taus258_state {
17 uint64_t s1, s2, s3, s4, s5;
18 };
19
20 struct frand_state {
21 unsigned int use64;
22 union {
23 struct taus88_state state32;
24 struct taus258_state state64;
25 };
26 };
27
rand_max(struct frand_state * state)28 static inline uint64_t rand_max(struct frand_state *state)
29 {
30 if (state->use64)
31 return FRAND64_MAX;
32 else
33 return FRAND32_MAX;
34 }
35
__frand32_copy(struct taus88_state * dst,struct taus88_state * src)36 static inline void __frand32_copy(struct taus88_state *dst,
37 struct taus88_state *src)
38 {
39 dst->s1 = src->s1;
40 dst->s2 = src->s2;
41 dst->s3 = src->s3;
42 }
43
__frand64_copy(struct taus258_state * dst,struct taus258_state * src)44 static inline void __frand64_copy(struct taus258_state *dst,
45 struct taus258_state *src)
46 {
47 dst->s1 = src->s1;
48 dst->s2 = src->s2;
49 dst->s3 = src->s3;
50 dst->s4 = src->s4;
51 dst->s5 = src->s5;
52 }
53
frand_copy(struct frand_state * dst,struct frand_state * src)54 static inline void frand_copy(struct frand_state *dst, struct frand_state *src)
55 {
56 if (src->use64)
57 __frand64_copy(&dst->state64, &src->state64);
58 else
59 __frand32_copy(&dst->state32, &src->state32);
60
61 dst->use64 = src->use64;
62 }
63
__rand32(struct taus88_state * state)64 static inline unsigned int __rand32(struct taus88_state *state)
65 {
66 #define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
67
68 state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12);
69 state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4);
70 state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17);
71
72 return (state->s1 ^ state->s2 ^ state->s3);
73 }
74
__rand64(struct taus258_state * state)75 static inline uint64_t __rand64(struct taus258_state *state)
76 {
77 uint64_t xval;
78
79 xval = ((state->s1 << 1) ^ state->s1) >> 53;
80 state->s1 = ((state->s1 & 18446744073709551614ULL) << 10) ^ xval;
81
82 xval = ((state->s2 << 24) ^ state->s2) >> 50;
83 state->s2 = ((state->s2 & 18446744073709551104ULL) << 5) ^ xval;
84
85 xval = ((state->s3 << 3) ^ state->s3) >> 23;
86 state->s3 = ((state->s3 & 18446744073709547520ULL) << 29) ^ xval;
87
88 xval = ((state->s4 << 5) ^ state->s4) >> 24;
89 state->s4 = ((state->s4 & 18446744073709420544ULL) << 23) ^ xval;
90
91 xval = ((state->s5 << 3) ^ state->s5) >> 33;
92 state->s5 = ((state->s5 & 18446744073701163008ULL) << 8) ^ xval;
93
94 return (state->s1 ^ state->s2 ^ state->s3 ^ state->s4 ^ state->s5);
95 }
96
__rand(struct frand_state * state)97 static inline uint64_t __rand(struct frand_state *state)
98 {
99 if (state->use64)
100 return __rand64(&state->state64);
101 else
102 return __rand32(&state->state32);
103 }
104
__rand_0_1(struct frand_state * state)105 static inline double __rand_0_1(struct frand_state *state)
106 {
107 if (state->use64) {
108 uint64_t val = __rand64(&state->state64);
109
110 return (val + 1.0) / (FRAND64_MAX + 1.0);
111 } else {
112 uint32_t val = __rand32(&state->state32);
113
114 return (val + 1.0) / (FRAND32_MAX + 1.0);
115 }
116 }
117
118 /*
119 * Generate a random value between 'start' and 'end', both inclusive
120 */
rand32_between(struct frand_state * state,int start,int end)121 static inline int rand32_between(struct frand_state *state, int start, int end)
122 {
123 uint32_t r;
124
125 assert(!state->use64);
126
127 r = __rand32(&state->state32);
128 return start + (int) ((double)end * (r / (FRAND32_MAX + 1.0)));
129 }
130
131 extern void init_rand(struct frand_state *, bool);
132 extern void init_rand_seed(struct frand_state *, unsigned int seed, bool);
133 extern void __fill_random_buf(void *buf, unsigned int len, unsigned long seed);
134 extern unsigned long fill_random_buf(struct frand_state *, void *buf, unsigned int len);
135 extern void __fill_random_buf_percentage(unsigned long, void *, unsigned int, unsigned int, unsigned int, char *, unsigned int);
136 extern unsigned long fill_random_buf_percentage(struct frand_state *, void *, unsigned int, unsigned int, unsigned int, char *, unsigned int);
137
138 #endif
139