1 files changed, 33 insertions, 0 deletions
diff --git a/sys/base/rng/random.c b/sys/base/rng/random.c
new file mode 100644
index 0000000..bd1bd6b
--- /dev/null
+++ b/sys/base/rng/random.c
@@ -0,0 +1,33 @@
+#include "internal.h"
+
+static uint64
+xoshiro256ss(Rng *state)
+{
+    uint64 *s     = state->s;
+    uint64 result = rol64(s[1] * 5, 7) * 9;
+    uint64 t      = s[1] << 17;
+
+    s[2] ^= s[0];
+    s[3] ^= s[1];
+    s[1] ^= s[2];
+    s[0] ^= s[3];
+
+    s[2] ^= t;
+    s[3] = rol64(s[3], 45);
+
+    return result;
+}
+
+double
+rng·random(void)
+{
+    uint64 r = xoshiro256ss(&rng·RNG);
+    return (double)r / (double)UINT64_MAX;
+}
+
+uint64
+rng·randi(int max)
+{
+    uint64 r = xoshiro256ss(&rng·RNG);
+    return r % max;
+}