aureooms/js-integer-big-endian

import _add from '../../../core/arithmetic/add/_add.js';

/**
 * Adds two big endian arrays and puts result in a destination array.
 * Wraps on overflow. Works with any combination of array sizes.
 *
 * @param {Number} r base (radix)
 * @param {Array} a first operand
 * @param {Number} ai a left
 * @param {Number} aj a right
 * @param {Array} b second operand
 * @param {Number} bi b left
 * @param {Number} bj b right
 * @param {Array} c result, must be 0 initialized
 * @param {Number} ci c left
 * @param {Number} cj c right
 *
 */
export default function add(r, a, ai, aj, b, bi, bj, c, ci, cj) {
    ci = Math.max(0, ci);
    const k = cj - ci;

    ai = Math.max(0, ai, aj - k);
    bi = Math.max(0, bi, bj - k);
    const m = aj - ai;
    const n = bj - bi;

    return m < n
        ? _add(r, b, bi, bj, a, ai, aj, c, ci, cj)
        : _add(r, a, ai, aj, b, bi, bj, c, ci, cj);
}