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Commit db3459d1 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

[IPV6]: Some cleanups in include/net/ipv6.h 



1) struct ip6_flowlabel : moves 'users' field to avoid two 32bits
   holes for 64bit arches. Shrinks by 8 bytes sizeof(struct
   ip6_flowlabel)

2) ipv6_addr_cmp() and ipv6_addr_copy() dont need (void *) casts :
   Compiler might take into account natural alignement of in6_addr
   structs to emit better code for memcpy()/memcmp() Casts to (void *)
   force byte accesses.

3) ipv6_addr_prefix() optimization :

Better to clear whole struct, as compiler can emit better code for
memset(addr, 0, 16) (2 stores on x86_64), and avoid some conditional
branches.

# size vmlinux.after vmlinux.before
   text    data     bss     dec     hex filename
5262262  647612  557432 6467306  62aeea vmlinux.after
5262550  647612  557432 6467594  62b00a vmlinux.before

thats 288 bytes saved.

Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b40b4f79

include/net/ipv6.h

+5 −8
Original line number Diff line number Diff line
@@ -204,9 +204,9 @@ struct ip6_flowlabel 
{

	struct ip6_flowlabel	*next;

	__be32			label;

	atomic_t		users;

	struct in6_addr		dst;

	struct ipv6_txoptions	*opt;

	atomic_t		users;

	unsigned long		linger;

	u8			share;

	u32			owner;
@@ -291,7 +291,7 @@ static inline int ipv6_addr_src_scope(const struct in6_addr *addr) 


static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)

{

	return memcmp((const void *) a1, (const void *) a2, sizeof(struct in6_addr));

	return memcmp(a1, a2, sizeof(struct in6_addr));

}



static inline int
@@ -308,7 +308,7 @@ ipv6_masked_addr_cmp(const struct in6_addr *a1, const struct in6_addr *m, 


static inline void ipv6_addr_copy(struct in6_addr *a1, const struct in6_addr *a2)

{

	memcpy((void *) a1, (const void *) a2, sizeof(struct in6_addr));

	memcpy(a1, a2, sizeof(struct in6_addr));

}



static inline void ipv6_addr_prefix(struct in6_addr *pfx,
@@ -319,13 +319,10 @@ static inline void ipv6_addr_prefix(struct in6_addr *pfx, 
	int o = plen >> 3,

	    b = plen & 0x7;



	memset(pfx->s6_addr, 0, sizeof(pfx->s6_addr));

	memcpy(pfx->s6_addr, addr, o);

	if (b != 0) {

	if (b != 0)

		pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b);

		o++;

	}

	if (o < 16)

		memset(pfx->s6_addr + o, 0, 16 - o);

}



static inline void ipv6_addr_set(struct in6_addr *addr,