Collatz Generators (#27)

* Create CG128.h

* Update rng.c

* Update rng.c

* Update rng.c

* Update rng.c

* Create CG64

* Rename CG64 to CG64.h

* Update rng.c

* Update CG128.h

* Update CG64.h

* Update CG128.h

* Create CG128-64.h

* Update CG128-64.h

* Update CG128.h

* Update CG64.h

* Update CG64.h

* Update rng.c

* Update rng.c

* Update CG64.h

* Update CG64.h

* Update CG64.h

* Update CG128-64.h

* Update CG128-64.h

* Update CG64.h

* Update CG128-64.h

* Update CG128-64.h

* Update CG128-64.h

* Create splitmix63.h

* Update splitmix63.h

* Update CG128-64.h

* Update CG64.h

* Update splitmix63.h

Author: TomaszRD

source/CG128-64.h

@@ -2,6 +2,7 @@
 #define CG128_64_H
 
 #include "splitmix64.h"
+#include "splitmix63.h"
 #include <stdint.h>
 
 /* Written in 2023 by Tomasz R. Dziala ([email protected]).
@@ -38,32 +39,16 @@ void initializator(void)
 static uint64_t CG_s, CG_k = 0, CG_weyl = 0;
 static __uint128_t CG_x;
 
-// call this to seed CG_x
+// call this to seed CG_x and CG_s
 static inline void CG128_64_seed(uint64_t seed) {
 	CG_x = ((__uint128_t)splitmix64_r(&seed) << 64) | (splitmix64_r(&seed) | 1);
+	CG_s = (splitmix63_r(&seed) << 1) | 1;
 }
 
-/* This is Splitmix63, modified Splitmix64 written in 2015 by Sebastiano Vigna. The state of Splitmix63
-may be seeded with any value. Outputs of Splitmix63 may be used to to serially seed c[0] states
-of Collatz Generator by s = (next_splitmix63() << 1) | 1; */
-
-// call this to seed CG_s
-
-static uint64_t CG64_128_y = 123;
-
-uint64_t CG64_128_next_splitmix63(void) {
- 	uint64_t CG64_128_z = (CG64_128_y += 0x9e3779b97f4a7c15) & 0x7fffffffffffffff;
-	CG64_128_z = ((CG64_128_z ^ (CG64_128_z >> 30)) * 0xbf58476d1ce4e5b9) & 0x7fffffffffffffff;
-	CG64_128_z = ((CG64_128_z ^ (CG64_128_z >> 27)) * 0x94d049bb133111eb) & 0x7fffffffffffffff;
-	return CG64_128_z ^ (CG64_128_z >> 31);
-}
-
-CG_s = (CG64_128_next_splitmix63() << 1) | 1;
-
 static inline __uint128_t CG128_64(void)
 {
-    CG_x = (CG_x | 1) * ((CG_k += CG_x) >> 1) ^ (CG_weyl += CG_s);
-    return CG_k >> 48 ^ CG_x;
+  CG_x = (CG_x | 1) * ((CG_k += CG_x) >> 1) ^ (CG_weyl += CG_s);
+  return CG_k >> 48 ^ CG_x;
 }
 
-#endif // CG128_64_H
+#endif // CG128_64_H

source/CG64.h

@@ -1,7 +1,7 @@
 #ifndef CG64_H
 #define CG64_H
 
-#include "splitmix64.h"
+#include "splitmix63.h"
 #include <stdint.h>
 
 /* Written in 2023 by Tomasz R. Dziala ([email protected]).
@@ -37,25 +37,15 @@ void initializator(void)
 
 static uint64_t CG64_c[4];
 
-/* This is Splitmix63, modified Splitmix64 written in 2015 by Sebastiano Vigna. The state of Splitmix63
-may be seeded with any value. Outputs of Splitmix63 may be used to to serially seed c[0] states
-of Collatz Generator by c[0] = (next_splitmix63() << 1) | 1; */
- 
-static uint64_t CG64_y = 123;
-
-uint64_t next_splitmix63(void) {
- 	uint64_t CG64_z = (CG64_y += 0x9e3779b97f4a7c15) & 0x7fffffffffffffff;
-	CG64_z = ((CG64_z ^ (CG64_z >> 30)) * 0xbf58476d1ce4e5b9) & 0x7fffffffffffffff;
-	CG64_z = ((CG64_z ^ (CG64_z >> 27)) * 0x94d049bb133111eb) & 0x7fffffffffffffff;
-	return CG64_z ^ (CG64_z >> 31);
+// call this to seed CG64_c[0]
+static inline void CG64_seed(uint64_t seed) {
+	CG64_c[0] = (splitmix63_r(&seed) << 1) | 1;
 }
 
-CG64_c[0] = (next_splitmix63() << 1) | 1;
-
 static inline uint64_t CG64(void)
 {
-    CG64_c[1] = (CG64_c[1] >> 1) * ((CG64_c[2] += CG64_c[1]) | 1) ^ (CG64_c[3] += CG64_c[0]);
-    return CG64_c[2] >> 48 ^ CG64_c[1];
+	CG64_c[1] = (CG64_c[1] >> 1) * ((CG64_c[2] += CG64_c[1]) | 1) ^ (CG64_c[3] += CG64_c[0]);
+	return CG64_c[2] >> 48 ^ CG64_c[1];
 }
 
-#endif // CG64_H
+#endif // CG64_H

source/splitmix63.h

@@ -0,0 +1,41 @@
+#ifndef SPLITMIX63_H
+#define SPLITMIX63_H
+
+/* This is Splitmix63, modified Splitmix64 written in 2015 by Sebastiano Vigna. The state of Splitmix63
+may be seeded with any value. */
+
+#include <stdint.h>
+
+// state for splitmix63
+uint64_t splitmix63_x; /* The state can be seeded with any value. */
+
+// call this one before calling splitmix64
+static inline void splitmix63_seed(uint64_t seed) { splitmix63_x = seed; }
+
+// floor( ( (1+sqrt(5))/2 ) * 2**64 MOD 2**64)
+#define GOLDEN_GAMMA UINT64_C(0x9E3779B97F4A7C15)
+
+static inline uint64_t splitmix63_r(uint64_t *seed) {
+  uint64_t z = (*seed += GOLDEN_GAMMA) & 0x7fffffffffffffff;
+  z = (z ^ (z >> 30)) * UINT64_C(0xBF58476D1CE4E5B9) & 0x7fffffffffffffff;
+  z = (z ^ (z >> 27)) * UINT64_C(0x94D049BB133111EB) & 0x7fffffffffffffff;
+  return z ^ (z >> 31);
+}
+
+static inline uint64_t splitmix63(void) {
+    return splitmix63_r(&splitmix63_x);
+}
+
+// returns the 32 least significant bits of a call to splitmix64
+// this is a simple (inlined) function call followed by a cast
+static inline uint32_t splitmix63_cast32(void) {
+  return (uint32_t)splitmix63();
+}
+
+// returns the value of splitmix64 "offset" steps from seed
+static inline uint64_t splitmix63_stateless(uint64_t seed, uint64_t offset) {
+  seed += offset*GOLDEN_GAMMA;
+  return splitmix63_r(&seed);
+}
+
+#endif // SPLITMIX63_H