Function AtomicInverseModPower2

src/cryptlib/integer.cpp:412–427

}

static void AtomicInverseModPower2(word *C, word A0, word A1)
{
    assert(A0%2==1);

    const dword A = MAKE_DWORD(A0, A1);
    dword_union R;
    R.dw = A0%8;

    for (unsigned i=3; i<2*WORD_BITS; i*=2)
        R.dw = R.dw*(2-R.dw*A);

    assert(R.dw*A==1);

    C[0] = R.low;
    C[1] = R.high;
}

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