JumpAhead for LFSR113

Author: cmcqueen

src/lib.rs

@@ -591,3 +591,53 @@ impl RngCore for LFSR113 {
         Ok(self.fill_bytes(dest))
     }
 }
+impl RngJumpAhead for LFSR113 {
+    fn jumpahead<N>(&mut self, n: N)
+        where N: Unsigned + PrimInt
+    {
+        const LFSR113_Z1_MATRIX_ARRAY: [u32; 32] = [
+            0x00000000, 0x00080000, 0x00100000, 0x00200000, 0x00400000, 0x00800000, 0x01000000, 0x02000001,
+            0x04000002, 0x08000004, 0x10000008, 0x20000010, 0x40000020, 0x80000041, 0x00000082, 0x00000104,
+            0x00000208, 0x00000410, 0x00000820, 0x00001040, 0x00002080, 0x00004100, 0x00008200, 0x00010400,
+            0x00020800, 0x00041000, 0x00002000, 0x00004000, 0x00008000, 0x00010000, 0x00020000, 0x00040000
+        ];
+        const LFSR113_Z2_MATRIX_ARRAY: [u32; 32] = [
+            0x00000000, 0x00000000, 0x00000000, 0x00000020, 0x00000040, 0x00000080, 0x00000100, 0x00000200,
+            0x00000400, 0x00000800, 0x00001000, 0x00002000, 0x00004000, 0x00008000, 0x00010000, 0x00020000,
+            0x00040000, 0x00080000, 0x00100000, 0x00200000, 0x00400000, 0x00800000, 0x01000000, 0x02000000,
+            0x04000000, 0x08000001, 0x10000002, 0x20000005, 0x4000000A, 0x80000014, 0x00000008, 0x00000010
+        ];
+        const LFSR113_Z3_MATRIX_ARRAY: [u32; 32] = [
+            0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000800, 0x00001000, 0x00002000, 0x00004000,
+            0x00008001, 0x00010002, 0x00020004, 0x00040008, 0x00080010, 0x00100020, 0x00200040, 0x00400080,
+            0x00800100, 0x01000200, 0x02000400, 0x04000000, 0x08000000, 0x10000001, 0x20000002, 0x40000004,
+            0x80000008, 0x00000010, 0x00000020, 0x00000040, 0x00000080, 0x00000100, 0x00000200, 0x00000400
+        ];
+        const LFSR113_Z4_MATRIX_ARRAY: [u32; 32] = [
+            0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00100000,
+            0x00200000, 0x00400001, 0x00800002, 0x01000004, 0x02000009, 0x04000012, 0x08000024, 0x10000048,
+            0x20000090, 0x40000120, 0x80000240, 0x00000480, 0x00000900, 0x00001200, 0x00002400, 0x00004800,
+            0x00009000, 0x00012000, 0x00024000, 0x00048000, 0x00090000, 0x00020000, 0x00040000, 0x00080000
+        ];
+
+        self.sanitise_z1();
+        let lfsr113_matrix = bitcolumnmatrix::BitColumnMatrix32::new(&LFSR113_Z1_MATRIX_ARRAY);
+        let lfsr113_mult = lfsr113_matrix.pow(n);
+        self.z1 = lfsr113_mult.dot_vec(self.z1);
+
+        self.sanitise_z2();
+        let lfsr113_matrix = bitcolumnmatrix::BitColumnMatrix32::new(&LFSR113_Z2_MATRIX_ARRAY);
+        let lfsr113_mult = lfsr113_matrix.pow(n);
+        self.z2 = lfsr113_mult.dot_vec(self.z2);
+
+        self.sanitise_z3();
+        let lfsr113_matrix = bitcolumnmatrix::BitColumnMatrix32::new(&LFSR113_Z3_MATRIX_ARRAY);
+        let lfsr113_mult = lfsr113_matrix.pow(n);
+        self.z3 = lfsr113_mult.dot_vec(self.z3);
+
+        self.sanitise_z4();
+        let lfsr113_matrix = bitcolumnmatrix::BitColumnMatrix32::new(&LFSR113_Z4_MATRIX_ARRAY);
+        let lfsr113_mult = lfsr113_matrix.pow(n);
+        self.z4 = lfsr113_mult.dot_vec(self.z4);
+    }
+}

src/main.rs

@@ -12,8 +12,8 @@ fn test_new_and_next_u32() {
     //let mut s = simplerandom::KISS::new(1, 2, 3, 4);
     //let mut s = simplerandom::MWC64::new(1, 2);
     //let mut s = simplerandom::KISS2::new(1, 2, 3, 4);
-    let mut s = simplerandom::LFSR88::new(1, 2, 3);
-    //let mut s = simplerandom::LFSR113::new(1, 2, 3, 4);
+    //let mut s = simplerandom::LFSR88::new(1, 2, 3);
+    let mut s = simplerandom::LFSR113::new(1, 2, 3, 4);
     for _ in 0..4 {
         println!("{}, {:?}", s.next_u32(), s);
         //println!("{}, {:?}", s.gen::<u32>(), s);