add tests for jump() and long_jump() to Xoshiro128PlusPlus and Xoshiro128StarStar

Author: walterdejong

rand_xoshiro/src/xoshiro128plusplus.rs

@@ -117,4 +117,30 @@ mod tests {
             assert_eq!(rng.next_u32(), e);
         }
     }
+
+    #[test]
+    fn test_jump() {
+        let mut rng = Xoshiro128PlusPlus::from_seed(
+            [1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4, 0, 0, 0]);
+        rng.jump();
+        // These values were produced by instrumenting the reference implementation:
+        // http://xoshiro.di.unimi.it/xoshiro128plus.c
+        assert_eq!(rng.s[0], 2843103750);
+        assert_eq!(rng.s[1], 2038079848);
+        assert_eq!(rng.s[2], 1533207345);
+        assert_eq!(rng.s[3], 44816753);
+    }
+
+    #[test]
+    fn test_long_jump() {
+        let mut rng = Xoshiro128PlusPlus::from_seed(
+            [1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4, 0, 0, 0]);
+        rng.long_jump();
+        // These values were produced by instrumenting the reference implementation:
+        // http://xoshiro.di.unimi.it/xoshiro128plus.c
+        assert_eq!(rng.s[0], 1611968294);
+        assert_eq!(rng.s[1], 2125834322);
+        assert_eq!(rng.s[2], 966769569);
+        assert_eq!(rng.s[3], 3193880526);
+    }
 }

rand_xoshiro/src/xoshiro128starstar.rs

@@ -117,4 +117,30 @@ mod tests {
             assert_eq!(rng.next_u32(), e);
         }
     }
+
+    #[test]
+    fn test_jump() {
+        let mut rng = Xoshiro128StarStar::from_seed(
+            [1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4, 0, 0, 0]);
+        rng.jump();
+        // These values were produced by instrumenting the reference implementation:
+        // http://xoshiro.di.unimi.it/xoshiro128plus.c
+        assert_eq!(rng.s[0], 2843103750);
+        assert_eq!(rng.s[1], 2038079848);
+        assert_eq!(rng.s[2], 1533207345);
+        assert_eq!(rng.s[3], 44816753);
+    }
+
+    #[test]
+    fn test_long_jump() {
+        let mut rng = Xoshiro128StarStar::from_seed(
+            [1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4, 0, 0, 0]);
+        rng.long_jump();
+        // These values were produced by instrumenting the reference implementation:
+        // http://xoshiro.di.unimi.it/xoshiro128plus.c
+        assert_eq!(rng.s[0], 1611968294);
+        assert_eq!(rng.s[1], 2125834322);
+        assert_eq!(rng.s[2], 966769569);
+        assert_eq!(rng.s[3], 3193880526);
+    }
 }