function md5cmn(q, a, b, x, s, t) {
        return safeAdd(
          bitRotateLeft(safeAdd(safeAdd(a, q), safeAdd(x, t)), s),
          b
        );
      }
Basic operation the algorithm uses.

@param {number} q q
@param {number} a a
@param {number} b b
@param {number} x x
@param {number} s s
@param {number} t t
@returns {number} Result