Function philox_round

src/framework/sampling/torch_random.cpp:38–51

    lo = static_cast<uint32_t>(product);
    hi = static_cast<uint32_t>(product >> 32U);
}

Philox4 philox_round(Philox4 counter, uint32_t key0, uint32_t key1) {
    uint32_t hi0 = 0;
    uint32_t lo0 = 0;
    uint32_t hi1 = 0;
    uint32_t lo1 = 0;
    mul_hi_lo(kPhiloxM0, counter.x, hi0, lo0);
    mul_hi_lo(kPhiloxM1, counter.z, hi1, lo1);
    return Philox4{
        hi1 ^ counter.y ^ key0,
        lo1,
        hi0 ^ counter.w ^ key1,
        lo0,
    };
}