Function transform

programs/obfuscator/Obfuscator.cpp:188–201

Pseudorandom permutation within set of numbers with the same log2(x).

/// Pseudorandom permutation within set of numbers with the same log2(x).
static UInt64 transform(UInt64 x, UInt64 seed)
{
    /// Keep 0 and 1 as is.
    if (x == 0 || x == 1)
        return x;

    /// Pseudorandom permutation of two elements.
    if (x == 2 || x == 3)
        return x ^ (seed & 1);

    size_t num_leading_zeros = std::countl_zero(x);

    return feistelNetwork(x, 64 - num_leading_zeros - 1, seed);
}


class UnsignedIntegerModel : public IModel