written to avoid multiple conditional jumps and avoid ugly repetitive
lines in the header file.
#define IN6_IS_ADDR_MC_GLOBAL(a) \
(IN6_IS_ADDR_MULTICAST(a) && ((((uint8_t *) (a))[1] & 0xf) == 0xe))
+#define __ARE_4_EQUAL(a,b) \
+ (!( 0[a]-0[b] | 1[a]-1[b] | 2[a]-2[b] | 3[a]-3[b] ))
+#define IN6_ARE_ADDR_EQUAL(a,b) \
+ __ARE_4_EQUAL((const uint32_t *)(a), (const uint32_t *)(b))
+
#define IN_CLASSA(a) ((((in_addr_t)(a)) & 0x80000000) == 0)
#define IN_CLASSA_NET 0xff000000
#define IN_CLASSA_NSHIFT 24