tweet dep break-up details

foo.c

// SEE: https://lemire.me/blog/2019/03/19/the-fastest-conventional-random-number-generator-that-can-pass-big-crush/

__uint128_t g_lehmer64_state;

uint64_t lehmer64() {
  uint64_t r = (g_lehmer64_state >> 64);
  g_lehmer64_state *= 0xda942042e4dd58b5;
  return r;
}


uint64_t wyhash64_x; 

uint64_t wyhash64()
{
  //wyhash64_x += 0x60bee2bee120fc15;
  __uint128_t tmp;
  tmp = (__uint128_t) wyhash64_x * 0xa3b195354a39b70d;

  wyhash64_x += 0x60bee2bee120fc15;
  
  uint64_t m1 = (tmp >> 64) ^ tmp;
  tmp = (__uint128_t)m1 * 0x1b03738712fad5c9;
  uint64_t m2 = (tmp >> 64) ^ tmp;
  
  return m2;
}