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-rw-r--r--src/util/rand_xor.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/src/util/rand_xor.c b/src/util/rand_xor.c
new file mode 100644
index 0000000000..07b4c22ee1
--- /dev/null
+++ b/src/util/rand_xor.c
@@ -0,0 +1,20 @@
+#include "rand_xor.h"
+
+/* Super fast random number generator.
+ *
+ * This rand_xorshift128plus function by Sebastiano Vigna belongs
+ * to the public domain.
+ */
+uint64_t
+rand_xorshift128plus(uint64_t *seed)
+{
+ uint64_t *s = seed;
+
+ uint64_t s1 = s[0];
+ const uint64_t s0 = s[1];
+ s[0] = s0;
+ s1 ^= s1 << 23;
+ s[1] = s1 ^ s0 ^ (s1 >> 18) ^ (s0 >> 5);
+
+ return s[1] + s0;
+}