C7
# define C7(K,i) ROTATE(Cx.q[K.c[(i)*8+7]],56)
# define C7(K,i) (Cx.q[7+8*K.c[(i)*8+7]])
# define C7(K,i) (((u64*)(Cx.c+1))[2*K.c[(i)*8+7]])