netfilter: optimize nf_inet_addr_cmp

optimize nf_inet_addr_cmp by 64bit xor computation
similar to ipv6_addr_equal()
Signed-off-by: Yuan Linsi <yuanlinsi01@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/linux/netfilter.h

@@ -24,10 +24,17 @@ static inline int NF_DROP_GETERR(int verdict)
 static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
 				   const union nf_inet_addr *a2)
 {
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
+	const unsigned long *ul1 = (const unsigned long *)a1;
+	const unsigned long *ul2 = (const unsigned long *)a2;
+
+	return ((ul1[0] ^ ul2[0]) | (ul1[1] ^ ul2[1])) == 0UL;
+#else
 	return a1->all[0] == a2->all[0] &&
 	       a1->all[1] == a2->all[1] &&
 	       a1->all[2] == a2->all[2] &&
 	       a1->all[3] == a2->all[3];
+#endif
 }
 
 static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,