Method Square

src/crypto/muhash.cpp:218–253

}

void Num3072::Square()
{
    limb_t c0 = 0, c1 = 0, c2 = 0;
    Num3072 tmp;

    /* Compute limbs 0..N-2 of this*this into tmp, including one reduction. */
    for (int j = 0; j < LIMBS - 1; ++j) {
        limb_t d0 = 0, d1 = 0, d2 = 0;
        for (int i = 0; i < (LIMBS - 1 - j) / 2; ++i) muldbladd3(d0, d1, d2, this->limbs[i + j + 1], this->limbs[LIMBS - 1 - i]);
        if ((j + 1) & 1) muladd3(d0, d1, d2, this->limbs[(LIMBS - 1 - j) / 2 + j + 1], this->limbs[LIMBS - 1 - (LIMBS - 1 - j) / 2]);
        mulnadd3(c0, c1, c2, d0, d1, d2, MAX_PRIME_DIFF);
        for (int i = 0; i < (j + 1) / 2; ++i) muldbladd3(c0, c1, c2, this->limbs[i], this->limbs[j - i]);
        if ((j + 1) & 1) muladd3(c0, c1, c2, this->limbs[(j + 1) / 2], this->limbs[j - (j + 1) / 2]);
        extract3(c0, c1, c2, tmp.limbs[j]);
    }

    assert(c2 == 0);
    for (int i = 0; i < LIMBS / 2; ++i) muldbladd3(c0, c1, c2, this->limbs[i], this->limbs[LIMBS - 1 - i]);
    extract3(c0, c1, c2, tmp.limbs[LIMBS - 1]);

    /* Perform a second reduction. */
    muln2(c0, c1, MAX_PRIME_DIFF);
    for (int j = 0; j < LIMBS; ++j) {
        addnextract2(c0, c1, tmp.limbs[j], this->limbs[j]);
    }

    assert(c1 == 0);
    assert(c0 == 0 || c0 == 1);

    /* Perform up to two more reductions if the internal state has already
     * overflown the MAX of Num3072 or if it is larger than the modulus or
     * if both are the case.
     * */
    if (this->IsOverflow()) this->FullReduce();
    if (c0) this->FullReduce();
}

void Num3072::SetToOne()
{