Switch to xorshift32 for fuzztest
Handling 64-bit seed values got annoying on AVR, and 32-bit
generator is enough for this test.
diff --git a/tests/fuzztest/fuzztest.c b/tests/fuzztest/fuzztest.c
index fac148c..a6c1330 100644
--- a/tests/fuzztest/fuzztest.c
+++ b/tests/fuzztest/fuzztest.c
@@ -22,16 +22,16 @@
#ifndef LLVMFUZZER
-static uint64_t random_seed;
+static uint32_t random_seed;
/* Uses xorshift64 here instead of rand() for both speed and
* reproducibility across platforms. */
static uint32_t rand_word()
{
- random_seed ^= random_seed >> 12;
- random_seed ^= random_seed << 25;
- random_seed ^= random_seed >> 27;
- return random_seed * 2685821657736338717ULL;
+ random_seed ^= random_seed << 13;
+ random_seed ^= random_seed >> 17;
+ random_seed ^= random_seed << 5;
+ return random_seed;
}
/* Get a random integer in range, with approximately flat distribution. */
@@ -511,13 +511,12 @@
if (argc >= 2)
{
/* Run in stand-alone mode */
- random_seed = atol(argv[1]);
+ random_seed = strtoul(argv[1], NULL, 0);
iterations = (argc >= 3) ? atol(argv[2]) : 10000;
- fprintf(stderr, "Random seed: %lu, iterations: %d\n", (unsigned long)random_seed, iterations);
for (i = 0; i < iterations; i++)
{
- fprintf(stderr, "Iteration %d/%d\n", i, iterations);
+ fprintf(stderr, "Iteration %d/%d, seed %lu\n", i, iterations, (unsigned long)random_seed);
run_iteration();
}
}
