Commit 1a203cb3 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ipv6: optimize ipv6 addresses compares 



On 64 bit arches having efficient unaligned accesses (eg x86_64) we can
use long words to reduce number of instructions for free.

Joe Perches suggested to change ipv6_masked_addr_cmp() to return a bool
instead of 'int', to make sure ipv6_masked_addr_cmp() cannot be used
in a sorting function.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1aa8b471

include/net/ipv6.h

+23 −1
Original line number Diff line number Diff line
@@ -298,14 +298,23 @@ static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr 
	return memcmp(a1, a2, sizeof(struct in6_addr));

}



static inline int

static inline bool

ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m,

		     const struct in6_addr *a2)

{

#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64

	const unsigned long *ul1 = (const unsigned long *)a1;

	const unsigned long *ulm = (const unsigned long *)m;

	const unsigned long *ul2 = (const unsigned long *)a2;



	return !!(((ul1[0] ^ ul2[0]) & ulm[0]) |

		  ((ul1[1] ^ ul2[1]) & ulm[1]));

#else

	return !!(((a1->s6_addr32[0] ^ a2->s6_addr32[0]) & m->s6_addr32[0]) |

		  ((a1->s6_addr32[1] ^ a2->s6_addr32[1]) & m->s6_addr32[1]) |

		  ((a1->s6_addr32[2] ^ a2->s6_addr32[2]) & m->s6_addr32[2]) |

		  ((a1->s6_addr32[3] ^ a2->s6_addr32[3]) & m->s6_addr32[3]));

#endif

}



static inline void ipv6_addr_prefix(struct in6_addr *pfx,
@@ -335,10 +344,17 @@ static inline void ipv6_addr_set(struct in6_addr *addr, 
static inline bool ipv6_addr_equal(const struct in6_addr *a1,

				   const struct in6_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->s6_addr32[0] ^ a2->s6_addr32[0]) |

		(a1->s6_addr32[1] ^ a2->s6_addr32[1]) |

		(a1->s6_addr32[2] ^ a2->s6_addr32[2]) |

		(a1->s6_addr32[3] ^ a2->s6_addr32[3])) == 0;

#endif

}



static inline bool __ipv6_prefix_equal(const __be32 *a1, const __be32 *a2,
@@ -391,8 +407,14 @@ bool ip6_frag_match(struct inet_frag_queue *q, void *a); 


static inline bool ipv6_addr_any(const struct in6_addr *a)

{

#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64

	const unsigned long *ul = (const unsigned long *)a;



	return (ul[0] | ul[1]) == 0UL;

#else

	return (a->s6_addr32[0] | a->s6_addr32[1] |

		a->s6_addr32[2] | a->s6_addr32[3]) == 0;

#endif

}



static inline bool ipv6_addr_loopback(const struct in6_addr *a)

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