PCG

code:c

// *Really* minimal PCG32 code / (c) 2014 M.E. O'Neill / pcg-random.org

// Licensed under Apache License 2.0 (NO WARRANTY, etc. see website)

typedef struct { uint64_t state; uint64_t inc; } pcg32_random_t;

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));

}