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

Bruce Richardson bruce.richardson at intel.com
Fri Jan 30 17:24:19 CET 2026


On Fri, Jan 30, 2026 at 08:20:28AM -0800, Stephen Hemminger wrote:
> On Fri, 30 Jan 2026 10:46:16 +0000
> Morten Brørup <mb at 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

+1 for just memcmp :-)


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