switch to faster and better hash + random

src/afl-performance.c

@@ -0,0 +1,135 @@
+/*  Written in 2019 by David Blackman and Sebastiano Vigna (vigna@acm.org)
+
+To the extent possible under law, the author has dedicated all copyright
+and related and neighboring rights to this software to the public domain
+worldwide. This software is distributed without any warranty.
+
+See <http://creativecommons.org/publicdomain/zero/1.0/>.
+
+   This is xoshiro256++ 1.0, one of our all-purpose, rock-solid generators.
+   It has excellent (sub-ns) speed, a state (256 bits) that is large
+   enough for any parallel application, and it passes all tests we are
+   aware of.
+
+   For generating just floating-point numbers, xoshiro256+ is even faster.
+
+   The state must be seeded so that it is not everywhere zero. If you have
+   a 64-bit seed, we suggest to seed a splitmix64 generator and use its
+   output to fill s. */
+
+#include <stdint.h>
+#include "afl-fuzz.h"
+#include "types.h"
+#include "xxh3.h"
+
+static inline uint64_t rotl(const uint64_t x, int k) {
+
+  return (x << k) | (x >> (64 - k));
+
+}
+
+uint64_t rand_next(afl_state_t *afl) {
+
+  const uint64_t result =
+      rotl(afl->rand_seed[0] + afl->rand_seed[3], 23) + afl->rand_seed[0];
+
+  const uint64_t t = afl->rand_seed[1] << 17;
+
+  afl->rand_seed[2] ^= afl->rand_seed[0];
+  afl->rand_seed[3] ^= afl->rand_seed[1];
+  afl->rand_seed[1] ^= afl->rand_seed[2];
+  afl->rand_seed[0] ^= afl->rand_seed[3];
+
+  afl->rand_seed[2] ^= t;
+
+  afl->rand_seed[3] = rotl(afl->rand_seed[3], 45);
+
+  return result;
+
+}
+
+/* This is the jump function for the generator. It is equivalent
+   to 2^128 calls to rand_next(); it can be used to generate 2^128
+   non-overlapping subsequences for parallel computations. */
+
+void jump(afl_state_t *afl) {
+
+  static const uint64_t JUMP[] = {0x180ec6d33cfd0aba, 0xd5a61266f0c9392c,
+                                  0xa9582618e03fc9aa, 0x39abdc4529b1661c};
+
+  uint64_t s0 = 0;
+  uint64_t s1 = 0;
+  uint64_t s2 = 0;
+  uint64_t s3 = 0;
+  for (int i = 0; i < sizeof JUMP / sizeof *JUMP; i++)
+    for (int b = 0; b < 64; b++) {
+
+      if (JUMP[i] & UINT64_C(1) << b) {
+
+        s0 ^= afl->rand_seed[0];
+        s1 ^= afl->rand_seed[1];
+        s2 ^= afl->rand_seed[2];
+        s3 ^= afl->rand_seed[3];
+
+      }
+
+      rand_next(afl);
+
+    }
+
+  afl->rand_seed[0] = s0;
+  afl->rand_seed[1] = s1;
+  afl->rand_seed[2] = s2;
+  afl->rand_seed[3] = s3;
+
+}
+
+/* This is the long-jump function for the generator. It is equivalent to
+   2^192 calls to rand_next(); it can be used to generate 2^64 starting points,
+   from each of which jump() will generate 2^64 non-overlapping
+   subsequences for parallel distributed computations. */
+
+void long_jump(afl_state_t *afl) {
+
+  static const uint64_t LONG_JUMP[] = {0x76e15d3efefdcbbf, 0xc5004e441c522fb3,
+                                       0x77710069854ee241, 0x39109bb02acbe635};
+
+  uint64_t s0 = 0;
+  uint64_t s1 = 0;
+  uint64_t s2 = 0;
+  uint64_t s3 = 0;
+  for (int i = 0; i < sizeof LONG_JUMP / sizeof *LONG_JUMP; i++)
+    for (int b = 0; b < 64; b++) {
+
+      if (LONG_JUMP[i] & UINT64_C(1) << b) {
+
+        s0 ^= afl->rand_seed[0];
+        s1 ^= afl->rand_seed[1];
+        s2 ^= afl->rand_seed[2];
+        s3 ^= afl->rand_seed[3];
+
+      }
+
+      rand_next(afl);
+
+    }
+
+  afl->rand_seed[0] = s0;
+  afl->rand_seed[1] = s1;
+  afl->rand_seed[2] = s2;
+  afl->rand_seed[3] = s3;
+
+}
+
+u32 hash32(const void *key, u32 len, u32 seed) {
+
+  return XXH64(key, len, seed) % 0x100000000;
+
+}
+
+u64 hash64(const void *key, u32 len, u64 seed) {
+
+  return XXH64(key, len, seed);
+
+}
+