1 files changed, 41 insertions, 0 deletions
diff --git a/test/mppa/prng/prng.c b/test/mppa/prng/prng.c
new file mode 100644
index 00000000..71de1dc3
--- /dev/null
+++ b/test/mppa/prng/prng.c
@@ -0,0 +1,41 @@
+// https://en.wikipedia.org/wiki/Linear_congruential_generator -> MMIX Donald Knuth
+// modulo 2^64 = no need to do it explicitly
+
+#include "types.h"
+
+#define MULTIPLIER 6364136223846793005LL
+#define INCREMENT 1442695040888963407LL
+
+static uint64_t current;
+
+void srand(uint64_t seed){
+    current = seed;
+}
+
+uint64_t randlong(void){
+    return (current = MULTIPLIER * current + INCREMENT);
+}
+
+#ifdef __UNIT_TEST_PRNG__
+char bytewise_sum(uint64_t to_check){
+    char sum = 0;
+    int i;
+
+    for (i = 0 ; i < 8 ; i++)
+        sum += (to_check & (uint64_t)(0xFFULL << i*8)) >> i*8;
+
+    return sum;
+}
+
+int main(void){
+    srand(42);
+    int i;
+
+    for (i = 0 ; i < 1000 ; i++)
+        randlong();
+
+    uint64_t last = randlong();
+
+    return !((unsigned char)bytewise_sum(last) == 155);
+}
+#endif // __UNIT_TEST_PRNG__