random routines

test_scripts/pseudorandom_gens/splitmix32.c

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+/* SplitMix32 test program
+ * Copyright (c) 2022 Joel K. Pettersson
+ * <joelkpettersson@gmail.com>.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+ #include "testwrite.h"
+ #include "muvaror32.h"
+ 
+ /*
+  * Here's SplitMix32 for comparison and a quick test.
+  */
+ 
+//FIBH32 = 2654435769U
+
+ /**
+  * Get next value for and update \p pos.
+  */
+ static inline uint32_t splitmix32(uint32_t *restrict pos) {
+     uint32_t s = *pos += FIBH32;
+     s ^= s >> 16;
+     s *= 0x85ebca6b;
+     s ^= s >> 13;
+     s *= 0xc2b2ae35;
+     s ^= s >> 16;
+     return s;
+ }
+ 
+ int main(int argc, char *argv[]) {
+     uint32_t pos = 0;
+     for (;;) {
+         /* SplitMix32 test */
+         add_output(splitmix32(&pos));
+     }
+     return 0;
+ }