lib/rand: get rid of unused MAX_SEED_BUCKETS
[fio.git] / lib / rand.c
index 618a2f06349dbc90389971b8720c9ea067024e28..0e787a62bad152568eee08824abf723716fec040 100644 (file)
 */
 
 #include <string.h>
-#include <assert.h>
 #include "rand.h"
+#include "pattern.h"
 #include "../hash.h"
 
-static inline int __seed(unsigned int x, unsigned int m)
+int arch_random;
+
+static inline uint64_t __seed(uint64_t x, uint64_t m)
 {
        return (x < m) ? x + m : x;
 }
 
-static void __init_rand(struct frand_state *state, unsigned int seed)
+static void __init_rand32(struct taus88_state *state, unsigned int seed)
 {
        int cranks = 6;
 
@@ -54,70 +56,101 @@ static void __init_rand(struct frand_state *state, unsigned int seed)
        state->s3 = __seed(LCG(state->s2, seed), 15);
 
        while (cranks--)
-               __rand(state);
+               __rand32(state);
 }
 
-void init_rand(struct frand_state *state)
+void __init_rand64(struct taus258_state *state, uint64_t seed)
 {
-       __init_rand(state, 1);
+       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_seed(struct frand_state *state, unsigned int seed)
+void init_rand(struct frand_state *state, bool use64)
 {
-       __init_rand(state, seed);
+       state->use64 = use64;
+
+       if (!use64)
+               __init_rand32(&state->state32, 1);
+       else
+               __init_rand64(&state->state64, 1);
 }
 
-void __fill_random_buf(void *buf, unsigned int len, unsigned long seed)
+void init_rand_seed(struct frand_state *state, uint64_t seed, bool use64)
 {
-       long *ptr = buf;
+       state->use64 = use64;
 
-       while ((void *) ptr - buf < len) {
-               *ptr = seed;
-               ptr++;
-               seed *= GOLDEN_RATIO_PRIME;
-               seed >>= 3;
-       }
+       if (!use64)
+               __init_rand32(&state->state32, (unsigned int) seed);
+       else
+               __init_rand64(&state->state64, seed);
 }
 
-unsigned long fill_random_buf(struct frand_state *fs, void *buf,
-                             unsigned int len)
+void __fill_random_buf_small(void *buf, unsigned int len, uint64_t seed)
 {
-       unsigned long r = __rand(fs);
+       uint64_t *b = buf;
+       uint64_t *e = b  + len / sizeof(*b);
+       unsigned int rest = len % sizeof(*b);
 
-       if (sizeof(int) != sizeof(long *))
-               r *= (unsigned long) __rand(fs);
+       for (; b != e; ++b) {
+               *b = seed;
+               seed = __hash_u64(seed);
+       }
 
-       __fill_random_buf(buf, len, r);
-       return r;
+       if (fio_unlikely(rest))
+               __builtin_memcpy(e, &seed, rest);
 }
 
-void fill_pattern(void *p, unsigned int len, char *pattern,
-                 unsigned int pattern_bytes)
+void __fill_random_buf(void *buf, unsigned int len, uint64_t seed)
 {
-       switch (pattern_bytes) {
-       case 0:
-               assert(0);
-               break;
-       case 1:
-               memset(p, pattern[0], len);
-               break;
-       default: {
-               unsigned int i = 0, size = 0;
-               unsigned char *b = p;
-
-               while (i < len) {
-                       size = pattern_bytes;
-                       if (size > (len - i))
-                               size = len - i;
-                       memcpy(b+i, pattern, size);
-                       i += size;
-               }
-               break;
+       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]);
 }
 
-void __fill_random_buf_percentage(unsigned long seed, void *buf,
+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)
@@ -126,7 +159,7 @@ void __fill_random_buf_percentage(unsigned long seed, void *buf,
 
        if (percentage == 100) {
                if (pbytes)
-                       fill_pattern(buf, len, pattern, pbytes);
+                       (void)cpy_pattern(pattern, pbytes, buf, len);
                else
                        memset(buf, 0, len);
                return;
@@ -139,20 +172,25 @@ void __fill_random_buf_percentage(unsigned long seed, void *buf,
                /*
                 * Fill random chunk
                 */
-               this_len = (segment * (100 - percentage)) / 100;
+               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)
-                       fill_pattern(buf, this_len, pattern, pbytes);
+                       (void)cpy_pattern(pattern, pbytes, buf, this_len);
                else
                        memset(buf, 0, this_len);
 
@@ -161,15 +199,12 @@ void __fill_random_buf_percentage(unsigned long seed, void *buf,
        }
 }
 
-unsigned long 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 fill_random_buf_percentage(struct frand_state *fs, void *buf,
+                                   unsigned int percentage,
+                                   unsigned int segment, unsigned int len,
+                                   char *pattern, unsigned int pbytes)
 {
-       unsigned long r = __rand(fs);
-
-       if (sizeof(int) != sizeof(long *))
-               r *= (unsigned long) __rand(fs);
+       uint64_t r = __get_next_seed(fs);
 
        __fill_random_buf_percentage(r, buf, percentage, segment, len,
                                        pattern, pbytes);