CARRY
x[2] = LOW(carry0 + carry1 + CARRY(p[1], r[0]) + q[1] + r[1] +
#define ADDEQU(x, y, z) (z = CARRY(x, (y)), x = LOW(x + (y)))
x[2] = LOW(carry0 + carry1 + CARRY(p[1], r[0]) + q[1] + r[1] +
#define ADDEQU(x, y, z) (z = CARRY(x, (y)), x = LOW(x + (y)))