[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: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 2ce3941..4fa5dfe 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -204,9 +204,9 @@
{
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_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 @@
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 @@
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,