Re: [PATCH 1/2] net: ethernet address comparison optimizations

Stephen Hemminger
2026-01-30T16:20:37Z

On Fri, 30 Jan 2026 10:46:16 +0000
Morten Brørup <mb@smartsharesystems.com> wrote:

> +__rte_pure
> static inline int rte_is_same_ether_addr(const struct rte_ether_addr *ea1,
> const struct rte_ether_addr *ea2)
> {
> +#if !defined(RTE_ARCH_STRICT_ALIGN)
> + return ((((const unaligned_uint32_t *)ea1)[0] ^ ((const unaligned_uint32_t *)ea2)[0]) |
> + (((const uint16_t *)ea1)[2] ^ ((const uint16_t *)ea2)[2])) == 0;
> +#else
> const uint16_t *w1 = (const uint16_t *)ea1;
> const uint16_t *w2 = (const uint16_t *)ea2;
>
> return ((w1[0] ^ w2[0]) | (w1[1] ^ w2[1]) | (w1[2] ^ w2[2])) == 0;
> +#endif
> }
>

FYI in Linux:

static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));

return fold == 0;
#else
const u16 *a = (const u16 *)addr1;
const u16 *b = (const u16 *)addr2;

return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
#endif
}

In FreeBSD kernel, there is no helper they just use memcmp