Define the Xor Shift Random Generator

valkyrie-language · Dec 11, 2023 · d679819 · d679819
1 parent 6db9d76
commit d679819
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diff --git a/projects/valkyrie-std/source/random/generator/LinearCongruential.vk b/projects/valkyrie-std/source/random/generator/LinearCongruential.vk
@@ -19,55 +19,3 @@ extends LinearCongruential {
         self.seed
     }
 }
-
-extends XorShift {
-    constructor(seed: u32?) {
-        self.state = seed ?? random_seed_safe() as u32;
-    }
-    random(mut self): u32 {
-        self.state.bit_xor_assign(self.state.bit_shift_left(13));
-        self.state.bit_xor_assign(self.state.bit_shift_right(17));
-        self.state.bit_xor_assign(self.state.bit_shift_left(5));
-        self.state
-    }
-}
-
-/// MT19937
-structure MersenneTwister32 {
-    seed: u64,
-    index: u64,
-    state: [u64; 624],
-}
-
-extends MersenneTwister32 {
-    constructor(seed: u64?) {
-        self.seed = seed ?? random_seed_safe();
-        self.index = 0;
-        self.state = [0; 624];
-        self.state[0] = self.seed;
-        for i in 1..624 {
-            self.state[i] = 1812433253 * (self.state[i - 1] ^ (self.state[i - 1] >> 30)) + i;
-        }
-    }
-    random(): u64 {
-        if self.index == 0 {
-            self.generate();
-        }
-        let mut y = self.state[self.index];
-        y ^= y >> 11;
-        y ^= (y << 7) & 2636928640;
-        y ^= (y << 15) & 4022730752;
-        y ^= y >> 18;
-        self.index = (self.index + 1) % 624;
-        y
-    }
-    sealed generate(): unit {
-        for i in range(624) {
-            let y = (self.state[i] & 16⁂80000000) + (self.state[(i + 1) % 624] & 16⁂7fffffff);
-            self.state[i] = self.state[(i + 397) % 624] ^ (y >> 1);
-            if y % 2 != 0 {
-                self.state[i] ^= 16⁂9908b0df;
-            }
-        }
-    }
-}
diff --git a/projects/valkyrie-std/source/random/generator/XorShift32.vk b/projects/valkyrie-std/source/random/generator/XorShift32.vk
@@ -0,0 +1,36 @@
+
+structure XorShift32 {
+    state: u32,
+    #constant
+    a: u32,
+    #constant
+    b: u32,
+    #constant
+    c: u32,
+}
+
+extends XorShift32 {
+    constructor(seed: u32?) {
+        self.a = 13;
+        self.b = 17;
+        self.c = 5;
+        self.state = seed ?? random_seed_safe().split_u32.2;
+    }
+    with_parameters(move self, a: u32, b: u32, c: u32): Self {
+        self.a = a;
+        self.b = b;
+        self.c = c;
+        self
+    }
+    #override(random_u32)
+    random(mut self): u32 {
+        self.state.bit_xor_assign(self.a.bit_shift_left(13));
+        self.state.bit_xor_assign(self.b.bit_shift_right(17));
+        self.state.bit_xor_assign(self.c.bit_shift_left(5));
+        self.state
+    }
+    #override(random_u32)
+    random(mut self): u64 {
+        u64::merge_u32(self.random(), self.random())
+    }
+}
diff --git a/projects/valkyrie-std/source/random/generator/XorShift64.vk b/projects/valkyrie-std/source/random/generator/XorShift64.vk
@@ -0,0 +1,35 @@
+
+
+structure XorShift64 {
+    state: u64,
+    #constant
+    a: u64,
+    #constant
+    b: u64,
+    #constant
+    c: u64,
+}
+
+extends XorShift32 {
+    constructor(seed: u64?) {
+        self.a = 13;
+        self.b = 7;
+        self.c = 17;
+        self.state = seed ?? random_seed_safe();
+    }
+    with_parameters(move self, a: u64, b: u64, c: u64): Self {
+        self.a = a;
+        self.b = b;
+        self.c = c;
+        self
+    }
+    random(mut self): u32 {
+        self.random().split_u32.2
+    }
+    random(mut self): u64 {
+        self.state.bit_xor_assign(self.a.bit_shift_left(13));
+        self.state.bit_xor_assign(self.b.bit_shift_right(17));
+        self.state.bit_xor_assign(self.c.bit_shift_left(5));
+        self.state
+    }
+}