+/*
+ This is a maximally equidistributed combined Tausworthe generator
+ based on code from GNU Scientific Library 1.5 (30 Jun 2004)
+
+ x_n = (s1_n ^ s2_n ^ s3_n)
+
+ s1_{n+1} = (((s1_n & 4294967294) <<12) ^ (((s1_n <<13) ^ s1_n) >>19))
+ s2_{n+1} = (((s2_n & 4294967288) << 4) ^ (((s2_n << 2) ^ s2_n) >>25))
+ s3_{n+1} = (((s3_n & 4294967280) <<17) ^ (((s3_n << 3) ^ s3_n) >>11))
+
+ The period of this generator is about 2^88.
+
+ From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe
+ Generators", Mathematics of Computation, 65, 213 (1996), 203--213.
+
+ This is available on the net from L'Ecuyer's home page,
+
+ http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
+ ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps
+
+ There is an erratum in the paper "Tables of Maximally
+ Equidistributed Combined LFSR Generators", Mathematics of
+ Computation, 68, 225 (1999), 261--269:
+ http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
+
+ ... the k_j most significant bits of z_j must be non-
+ zero, for each j. (Note: this restriction also applies to the
+ computer code given in [4], but was mistakenly not mentioned in
+ that paper.)
+
+ This affects the seeding procedure by imposing the requirement
+ s1 > 1, s2 > 7, s3 > 15.
+
+*/
+
+#include <string.h>
#include "rand.h"
+#include "pattern.h"
+#include "../hash.h"
-struct frand_state __fio_rand_state;
+int arch_random;
-static inline int __seed(unsigned int x, unsigned int m)
+static inline uint64_t __seed(uint64_t x, uint64_t m)
{
return (x < m) ? x + m : x;
}
-void init_rand(struct frand_state *state)
+static void __init_rand32(struct taus88_state *state, unsigned int seed)
+{
+ int cranks = 6;
+
+#define LCG(x, seed) ((x) * 69069 ^ (seed))
+
+ state->s1 = __seed(LCG((2^31) + (2^17) + (2^7), seed), 1);
+ state->s2 = __seed(LCG(state->s1, seed), 7);
+ state->s3 = __seed(LCG(state->s2, seed), 15);
+
+ while (cranks--)
+ __rand32(state);
+}
+
+void __init_rand64(struct taus258_state *state, uint64_t seed)
+{
+ int cranks = 6;
+
+#define LCG64(x, seed) ((x) * 6906969069ULL ^ (seed))
+
+ state->s1 = __seed(LCG64((2^31) + (2^17) + (2^7), seed), 1);
+ state->s2 = __seed(LCG64(state->s1, seed), 7);
+ state->s3 = __seed(LCG64(state->s2, seed), 15);
+ state->s4 = __seed(LCG64(state->s3, seed), 33);
+ state->s5 = __seed(LCG64(state->s4, seed), 49);
+
+ while (cranks--)
+ __rand64(state);
+}
+
+void init_rand(struct frand_state *state, bool use64)
{
-#define LCG(x) ((x) * 69069) /* super-duper LCG */
+ state->use64 = use64;
- state->s1 = __seed(LCG((2^31) + (2^17) + (2^7)), 1);
- state->s2 = __seed(LCG(state->s1), 7);
- state->s3 = __seed(LCG(state->s2), 15);
+ if (!use64)
+ __init_rand32(&state->state32, 1);
+ else
+ __init_rand64(&state->state64, 1);
+}
+
+void init_rand_seed(struct frand_state *state, uint64_t seed, bool use64)
+{
+ state->use64 = use64;
+
+ if (!use64)
+ __init_rand32(&state->state32, (unsigned int) seed);
+ else
+ __init_rand64(&state->state64, seed);
+}
+
+void __fill_random_buf_small(void *buf, unsigned int len, uint64_t seed)
+{
+ uint64_t *b = buf;
+ uint64_t *e = b + len / sizeof(*b);
+ unsigned int rest = len % sizeof(*b);
+
+ for (; b != e; ++b) {
+ *b = seed;
+ seed = __hash_u64(seed);
+ }
+
+ if (fio_unlikely(rest))
+ __builtin_memcpy(e, &seed, rest);
+}
+
+void __fill_random_buf(void *buf, unsigned int len, uint64_t seed)
+{
+ static uint64_t prime[] = {1, 2, 3, 5, 7, 11, 13, 17,
+ 19, 23, 29, 31, 37, 41, 43, 47};
+ uint64_t *b, *e, s[CONFIG_SEED_BUCKETS];
+ unsigned int rest;
+ int p;
+
+ /*
+ * Calculate the max index which is multiples of the seed buckets.
+ */
+ rest = (len / sizeof(*b) / CONFIG_SEED_BUCKETS) * CONFIG_SEED_BUCKETS;
+
+ b = buf;
+ e = b + rest;
+
+ rest = len - (rest * sizeof(*b));
+
+ for (p = 0; p < CONFIG_SEED_BUCKETS; p++)
+ s[p] = seed * prime[p];
+
+ for (; b != e; b += CONFIG_SEED_BUCKETS) {
+ for (p = 0; p < CONFIG_SEED_BUCKETS; ++p) {
+ b[p] = s[p];
+ s[p] = __hash_u64(s[p]);
+ }
+ }
+
+ __fill_random_buf_small(b, rest, s[0]);
+}
+
+uint64_t fill_random_buf(struct frand_state *fs, void *buf,
+ unsigned int len)
+{
+ uint64_t r = __get_next_seed(fs);
+
+ __fill_random_buf(buf, len, r);
+ return r;
+}
+
+void __fill_random_buf_percentage(uint64_t seed, void *buf,
+ unsigned int percentage,
+ unsigned int segment, unsigned int len,
+ char *pattern, unsigned int pbytes)
+{
+ unsigned int this_len;
+
+ if (percentage == 100) {
+ if (pbytes)
+ (void)cpy_pattern(pattern, pbytes, buf, len);
+ else
+ memset(buf, 0, len);
+ return;
+ }
+
+ if (segment > len)
+ segment = len;
+
+ while (len) {
+ /*
+ * Fill random chunk
+ */
+ this_len = ((unsigned long long)segment * (100 - percentage)) / 100;
+ if (this_len > len)
+ this_len = len;
+
+ __fill_random_buf(buf, this_len, seed);
+
+ len -= this_len;
+ if (!len)
+ break;
+ buf += this_len;
+ this_len = segment - this_len;
+
+ if (this_len > len)
+ this_len = len;
+ else if (len - this_len <= sizeof(long))
+ this_len = len;
+
+ if (pbytes)
+ (void)cpy_pattern(pattern, pbytes, buf, this_len);
+ else
+ memset(buf, 0, this_len);
+
+ len -= this_len;
+ buf += this_len;
+ }
+}
+
+uint64_t fill_random_buf_percentage(struct frand_state *fs, void *buf,
+ unsigned int percentage,
+ unsigned int segment, unsigned int len,
+ char *pattern, unsigned int pbytes)
+{
+ uint64_t r = __get_next_seed(fs);
- __rand(state);
- __rand(state);
- __rand(state);
- __rand(state);
- __rand(state);
- __rand(state);
+ __fill_random_buf_percentage(r, buf, percentage, segment, len,
+ pattern, pbytes);
+ return r;
}
projects / fio.git / blobdiff