aureooms/js-integer-big-endian

import assert from 'assert';

/**
 * Divides a big endian number by a single limb number.
 * Can only work with limbs of size at most sqrt( 2^53 ).
 * Allows to prefix the dividend with an intermediate remainder.
 *
 * Does not update the remainder.
 *
 * Input
 * -----
 *  - 0 <= tmp <= d - 1
 *  - 1 <= d <= r - 1
 *  - |Q| = |D|
 *
 * @param {Number} r The radix.
 * @param {Number} tmp Intermediate remainder (MUST be <code>< d</code>).
 * @param {Number} d The divisor >= 1.
 * @param {Array} D The dividend (NOT modified).
 * @param {Number} Di Left of dividend.
 * @param {Number} Dj Right of dividend.
 * @param {Array} Q The quotient.
 * @param {Number} Qi Left of quotient.
 */
export default function _div_limb_with_prefix(r, tmp, d, D, Di, Dj, Q, Qi) {
    assert(r >= 2);
    assert(d >= 1 && d <= r - 1);
    assert(tmp >= 0 && tmp <= d - 1);
    assert(Di >= 0 && Dj <= D.length);
    assert(Qi >= 0);
    assert(Dj - Di <= Q.length - Qi);

    while (Di < Dj) {
        tmp *= r;
        tmp += D[Di];

        Q[Qi] = (tmp / d) | 0;
        tmp %= d;

        ++Qi;
        ++Di;
    }
}