PCG is covered in sources [0-2] and my comment. It's great, but without AVX512, it's ~70% as fast as AES-CTR, lehmer64, splitmix64, and the xorshi*[0-9]\+plus families of RNGs, which in [1] were all roughly the same speed. In [2], Lemire's PCG implementation is even faster than his AVX512 version of xorshift128+.