ipv6: Optimize ipv6_addr_is_solict_mult().

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/addrconf.h

@@ -307,10 +307,17 @@ static inline bool ipv6_addr_is_isatap(const struct in6_addr *addr)
 
 static inline bool ipv6_addr_is_solict_mult(const struct in6_addr *addr)
 {
-	return (addr->s6_addr32[0] == htonl(0xff020000) &&
-		addr->s6_addr32[1] == htonl(0x00000000) &&
-		addr->s6_addr32[2] == htonl(0x00000001) &&
-		addr->s6_addr[12] == 0xff);
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
+	__u64 *p = (__u64 *)addr;
+	return ((p[0] ^ cpu_to_be64(0xff02000000000000UL)) |
+		((p[1] ^ cpu_to_be64(0x00000001ff000000UL)) &
+		 cpu_to_be64(0xffffffffff000000UL))) == 0UL;
+#else
+	return ((addr->s6_addr32[0] ^ htonl(0xff020000)) |
+		addr->s6_addr32[1] |
+		(addr->s6_addr32[2] ^ htonl(0x00000001)) |
+		(addr->s6_addr[12] ^ 0xff)) == 0;
+#endif
 }
 
 #ifdef CONFIG_PROC_FS