diff options
Diffstat (limited to 'thirdparty/misc/pcg.cpp')
-rw-r--r-- | thirdparty/misc/pcg.cpp | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/thirdparty/misc/pcg.cpp b/thirdparty/misc/pcg.cpp new file mode 100644 index 0000000000..eac3b36d36 --- /dev/null +++ b/thirdparty/misc/pcg.cpp @@ -0,0 +1,15 @@ +// *Really* minimal PCG32 code / (c) 2014 M.E. O'Neill / pcg-random.org +// Licensed under Apache License 2.0 (NO WARRANTY, etc. see website) + +#include "pcg.h" + +uint32_t pcg32_random_r(pcg32_random_t* rng) +{ + uint64_t oldstate = rng->state; + // Advance internal state + rng->state = oldstate * 6364136223846793005ULL + (rng->inc|1); + // Calculate output function (XSH RR), uses old state for max ILP + uint32_t xorshifted = ((oldstate >> 18u) ^ oldstate) >> 27u; + uint32_t rot = oldstate >> 59u; + return (xorshifted >> rot) | (xorshifted << ((-rot) & 31)); +} |