_REG_Y
r[_REG_Y] = tf->tf_y;
tf->tf_y = r[_REG_Y];
gr[_REG_Y] = tf->tf_y;
tf->tf_y = (uint64_t)gr[_REG_Y];
gr[_REG_Y] = tf->tf_y;
tf->tf_y = (uint64_t)gr[_REG_Y];