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optimize 16- and 32-bit moves

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function                                             old     new   delta
udhcpd_main                                         1239    1257     +18
udhcp_add_simple_option                               93      92      -1
buffer_read_le_u32                                    19      18      -1
unpack_gz_stream_with_info                           526     520      -6
dnsd_main                                           1470    1463      -7
udhcp_run_script                                    1208    1186     -22
send_ACK                                             255     229     -26
arping_main                                         1661    1623     -38
send_offer                                           470     428     -42
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/8 up/down: 18/-143)          Total: -125 bytes
This commit is contained in:
Denis Vlasenko 2008-12-08 22:56:18 +00:00
parent d1a84a2880
commit efb545b9bd
13 changed files with 97 additions and 77 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
archival/libunarchive/decompress_unzip.c
View File

@ -1083,8 +1083,7 @@ static uint16_t buffer_read_le_u16(STATE_PARAM_ONLY)
{
uint16_t res;
#if BB_LITTLE_ENDIAN
/* gcc 4.2.1 is very clever */
memcpy(&res, &bytebuffer[bytebuffer_offset], 2);
move_from_unaligned16(res, &bytebuffer[bytebuffer_offset]);
#else
res = bytebuffer[bytebuffer_offset];
res |= bytebuffer[bytebuffer_offset + 1] << 8;
@ -1097,7 +1096,7 @@ static uint32_t buffer_read_le_u32(STATE_PARAM_ONLY)
{
uint32_t res;
#if BB_LITTLE_ENDIAN
memcpy(&res, &bytebuffer[bytebuffer_offset], 4);
move_from_unaligned32(res, &bytebuffer[bytebuffer_offset]);
#else
res = bytebuffer[bytebuffer_offset];
res |= bytebuffer[bytebuffer_offset + 1] << 8;

12
include/platform.h
View File

@ -151,13 +151,19 @@
/* ---- Unaligned access ------------------------------------ */
/* parameter is supposed to be an uint32_t* ptr */
/* NB: unaligned parameter should be a pointer, aligned one -
* a lvalue. This makes it more likely to not swap them by mistake
*/
#if defined(i386) || defined(__x86_64__)
#define get_unaligned_u32p(u32p) (*(u32p))
#define move_from_unaligned16(v, u16p) ((v) = *(uint16_t*)(u16p))
#define move_from_unaligned32(v, u32p) ((v) = *(uint32_t*)(u32p))
#define move_to_unaligned32(u32p, v) (*(uint32_t*)(u32p) = (v))
/* #elif ... - add your favorite arch today! */
#else
/* performs reasonably well (gcc usually inlines memcpy here) */
#define get_unaligned_u32p(u32p) ({ uint32_t __t; memcpy(&__t, (u32p), 4); __t; })
#define move_from_unaligned16(v, u16p) (memcpy(&(v), (u16p), 2))
#define move_from_unaligned32(v, u32p) (memcpy(&(v), (u32p), 4))
#define move_to_unaligned32(u32p, v) (memcpy((u32p), &(v), 4))
#endif
/* ---- Networking ------------------------------------------ */

15
networking/arping.c
View File

@ -153,6 +153,15 @@ static bool recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM)
struct arphdr *ah = (struct arphdr *) buf;
unsigned char *p = (unsigned char *) (ah + 1);
struct in_addr src_ip, dst_ip;
/* moves below assume in_addr is 4 bytes big, ensure that */
struct BUG_in_addr_must_be_4 {
char BUG_in_addr_must_be_4[
sizeof(struct in_addr) == 4 ? 1 : -1
];
char BUG_s_addr_must_be_4[
sizeof(src_ip.s_addr) == 4 ? 1 : -1
];
};
/* Filter out wild packets */
if (FROM->sll_pkttype != PACKET_HOST
@ -176,8 +185,8 @@ static bool recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM)
|| (len < (int)(sizeof(*ah) + 2 * (4 + ah->ar_hln))))
return false;
memcpy(&src_ip, p + ah->ar_hln, 4);
memcpy(&dst_ip, p + ah->ar_hln + 4 + ah->ar_hln, 4);
move_from_unaligned32(src_ip.s_addr, p + ah->ar_hln);
move_from_unaligned32(dst_ip.s_addr, p + ah->ar_hln + 4 + ah->ar_hln);
if (dst.s_addr != src_ip.s_addr)
return false;
@ -306,7 +315,7 @@ int arping_main(int argc UNUSED_PARAM, char **argv)
/* if (!inet_aton(target, &dst)) - not needed */ {
len_and_sockaddr *lsa;
lsa = xhost_and_af2sockaddr(target, 0, AF_INET);
memcpy(&dst, &lsa->u.sin.sin_addr.s_addr, 4);
dst = lsa->u.sin.sin_addr;
if (ENABLE_FEATURE_CLEAN_UP)
free(lsa);
}

2
networking/dnsd.c
View File

@ -253,7 +253,7 @@ static int process_packet(uint8_t *buf)
goto empty_packet;
}
v32 = a.s_addr; /* in case long != int */
memcpy(answstr, &v32, 4);
move_to_unaligned32(answstr, v32);
outr_rlen = 4; // uint32_t IP
} else
outr_rlen = strlen((char *)answstr) + 1; // a host name

4
networking/libiproute/libnetlink.c
View File

@ -341,7 +341,7 @@ int FAST_FUNC addattr32(struct nlmsghdr *n, int maxlen, int type, uint32_t data)
rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len));
rta->rta_type = type;
rta->rta_len = len;
memcpy(RTA_DATA(rta), &data, 4);
move_to_unaligned32(RTA_DATA(rta), data);
n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
return 0;
}
@ -372,7 +372,7 @@ int FAST_FUNC rta_addattr32(struct rtattr *rta, int maxlen, int type, uint32_t d
subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
subrta->rta_type = type;
subrta->rta_len = len;
memcpy(RTA_DATA(subrta), &data, 4);
move_to_unaligned32(RTA_DATA(subrta), data);
rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
return 0;
}

8
networking/libiproute/ll_addr.c
View File

@ -43,6 +43,8 @@ const char *ll_addr_n2a(unsigned char *addr, int alen, int type, char *buf, int
int ll_addr_a2n(unsigned char *lladdr, int len, char *arg)
{
int i;
if (strchr(arg, '.')) {
inet_prefix pfx;
if (get_addr_1(&pfx, arg, AF_INET)) {
@ -54,10 +56,9 @@ int ll_addr_a2n(unsigned char *lladdr, int len, char *arg)
}
memcpy(lladdr, pfx.data, 4);
return 4;
} else {
int i;
}
for (i=0; i<len; i++) {
for (i = 0; i < len; i++) {
int temp;
char *cp = strchr(arg, ':');
if (cp) {
@ -75,5 +76,4 @@ int ll_addr_a2n(unsigned char *lladdr, int len, char *arg)
arg = cp;
}
return i+1;
}
}

4
networking/udhcp/dhcpc.c
View File

@ -503,7 +503,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
/* still selecting - this server looks bad */
}
/* it IS unaligned sometimes, don't "optimize" */
server_addr = get_unaligned_u32p((uint32_t*)temp);
move_from_unaligned32(server_addr, temp);
xid = packet.xid;
requested_ip = packet.yiaddr;
@ -525,7 +525,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
lease_seconds = 60 * 60;
} else {
/* it IS unaligned sometimes, don't "optimize" */
lease_seconds = get_unaligned_u32p((uint32_t*)temp);
move_from_unaligned32(lease_seconds, temp);
lease_seconds = ntohl(lease_seconds);
lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */
if (lease_seconds < 10) /* and not too small */

25
networking/udhcp/dhcpd.c
View File

@ -30,7 +30,9 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
int server_socket = -1, bytes, retval, max_sock;
struct dhcpMessage packet;
uint8_t *state, *server_id, *requested;
uint32_t server_id_align, requested_align, static_lease_ip;
uint32_t server_id_aligned = server_id_aligned; /* for compiler */
uint32_t requested_aligned = requested_aligned;
uint32_t static_lease_ip;
unsigned timeout_end;
unsigned num_ips;
unsigned opt;
@ -79,7 +81,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
option = find_option(server_config.options, DHCP_LEASE_TIME);
server_config.lease = LEASE_TIME;
if (option) {
memcpy(&server_config.lease, option->data + 2, 4);
move_from_unaligned32(server_config.lease, option->data + 2);
server_config.lease = ntohl(server_config.lease);
}
@ -190,21 +192,24 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
requested = get_option(&packet, DHCP_REQUESTED_IP);
server_id = get_option(&packet, DHCP_SERVER_ID);
if (requested) memcpy(&requested_align, requested, 4);
if (server_id) memcpy(&server_id_align, server_id, 4);
if (requested)
move_from_unaligned32(requested_aligned, requested);
if (server_id)
move_from_unaligned32(server_id_aligned, server_id);
if (lease) {
if (server_id) {
/* SELECTING State */
DEBUG("server_id = %08x", ntohl(server_id_align));
if (server_id_align == server_config.server && requested
&& requested_align == lease->yiaddr
DEBUG("server_id = %08x", ntohl(server_id_aligned));
if (server_id_aligned == server_config.server
&& requested
&& requested_aligned == lease->yiaddr
) {
send_ACK(&packet, lease->yiaddr);
}
} else if (requested) {
/* INIT-REBOOT State */
if (lease->yiaddr == requested_align)
if (lease->yiaddr == requested_aligned)
send_ACK(&packet, lease->yiaddr);
else
send_NAK(&packet);
@ -221,7 +226,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
} else if (requested) {
/* INIT-REBOOT State */
lease = find_lease_by_yiaddr(requested_align);
lease = find_lease_by_yiaddr(requested_aligned);
if (lease) {
if (lease_expired(lease)) {
/* probably best if we drop this lease */
@ -230,7 +235,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
} else
send_NAK(&packet);
} else {
uint32_t r = ntohl(requested_align);
uint32_t r = ntohl(requested_aligned);
if (r < server_config.start_ip
|| r > server_config.end_ip
) {

5
networking/udhcp/options.c
View File

@ -224,9 +224,8 @@ int FAST_FUNC add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data)
option[OPT_LEN] = len;
if (BB_BIG_ENDIAN)
data <<= 8 * (4 - len);
/* This memcpy is for processors which can't
* handle a simple unaligned 32-bit assignment */
memcpy(&option[OPT_DATA], &data, 4);
/* Assignment is unaligned! */
move_to_unaligned32(&option[OPT_DATA], data);
return add_option_string(optionptr, option);
}
}

10
networking/udhcp/script.c
View File

@ -90,19 +90,19 @@ static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p,
dest += sprintf(dest, "%u", *option);
break;
case OPTION_U16:
memcpy(&val_u16, option, 2);
move_from_unaligned16(val_u16, option);
dest += sprintf(dest, "%u", ntohs(val_u16));
break;
case OPTION_S16:
memcpy(&val_s16, option, 2);
move_from_unaligned16(val_s16, option);
dest += sprintf(dest, "%d", ntohs(val_s16));
break;
case OPTION_U32:
memcpy(&val_u32, option, 4);
move_from_unaligned32(val_u32, option);
dest += sprintf(dest, "%lu", (unsigned long) ntohl(val_u32));
break;
case OPTION_S32:
memcpy(&val_s32, option, 4);
move_from_unaligned32(val_s32, option);
dest += sprintf(dest, "%ld", (long) ntohl(val_s32));
break;
case OPTION_STRING:
@ -183,7 +183,7 @@ static char **fill_envp(struct dhcpMessage *packet)
/* Fill in a subnet bits option for things like /24 */
if (dhcp_options[i].code == DHCP_SUBNET) {
uint32_t subnet;
memcpy(&subnet, temp, 4);
move_from_unaligned32(subnet, temp);
envp[j++] = xasprintf("mask=%d", mton(subnet));
}
next:

37
networking/udhcp/serverpacket.c
View File

@ -103,7 +103,8 @@ int FAST_FUNC send_offer(struct dhcpMessage *oldpacket)
{
struct dhcpMessage packet;
struct dhcpOfferedAddr *lease = NULL;
uint32_t req_align, lease_time_align = server_config.lease;
uint32_t req_align;
uint32_t lease_time_aligned = server_config.lease;
uint8_t *req, *lease_time;
struct option_set *curr;
struct in_addr addr;
@ -120,7 +121,7 @@ int FAST_FUNC send_offer(struct dhcpMessage *oldpacket)
lease = find_lease_by_chaddr(oldpacket->chaddr);
if (lease) {
if (!lease_expired(lease))
lease_time_align = lease->expires - time(0);
lease_time_aligned = lease->expires - time(0);
packet.yiaddr = lease->yiaddr;
/* Or the client has a requested ip */
} else if ((req = get_option(oldpacket, DHCP_REQUESTED_IP))
@ -155,22 +156,22 @@ int FAST_FUNC send_offer(struct dhcpMessage *oldpacket)
}
lease_time = get_option(oldpacket, DHCP_LEASE_TIME);
if (lease_time) {
memcpy(&lease_time_align, lease_time, 4);
lease_time_align = ntohl(lease_time_align);
if (lease_time_align > server_config.lease)
lease_time_align = server_config.lease;
move_from_unaligned32(lease_time_aligned, lease_time);
lease_time_aligned = ntohl(lease_time_aligned);
if (lease_time_aligned > server_config.lease)
lease_time_aligned = server_config.lease;
}
/* Make sure we aren't just using the lease time from the previous offer */
if (lease_time_align < server_config.min_lease)
lease_time_align = server_config.lease;
if (lease_time_aligned < server_config.min_lease)
lease_time_aligned = server_config.lease;
/* ADDME: end of short circuit */
} else {
/* It is a static lease... use it */
packet.yiaddr = static_lease_ip;
}
add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_align));
add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_aligned));
curr = server_config.options;
while (curr) {
@ -203,7 +204,7 @@ int FAST_FUNC send_ACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
struct dhcpMessage packet;
struct option_set *curr;
uint8_t *lease_time;
uint32_t lease_time_align = server_config.lease;
uint32_t lease_time_aligned = server_config.lease;
struct in_addr addr;
init_packet(&packet, oldpacket, DHCPACK);
@ -211,15 +212,15 @@ int FAST_FUNC send_ACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
lease_time = get_option(oldpacket, DHCP_LEASE_TIME);
if (lease_time) {
memcpy(&lease_time_align, lease_time, 4);
lease_time_align = ntohl(lease_time_align);
if (lease_time_align > server_config.lease)
lease_time_align = server_config.lease;
else if (lease_time_align < server_config.min_lease)
lease_time_align = server_config.lease;
move_from_unaligned32(lease_time_aligned, lease_time);
lease_time_aligned = ntohl(lease_time_aligned);
if (lease_time_aligned > server_config.lease)
lease_time_aligned = server_config.lease;
else if (lease_time_aligned < server_config.min_lease)
lease_time_aligned = server_config.lease;
}
add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_align));
add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_aligned));
curr = server_config.options;
while (curr) {
@ -236,7 +237,7 @@ int FAST_FUNC send_ACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
if (send_packet(&packet, 0) < 0)
return -1;
add_lease(packet.chaddr, packet.yiaddr, lease_time_align);
add_lease(packet.chaddr, packet.yiaddr, lease_time_aligned);
if (ENABLE_FEATURE_UDHCPD_WRITE_LEASES_EARLY) {
/* rewrite the file with leases at every new acceptance */
write_leases();

3
networking/zcip.c
View File

@ -279,7 +279,8 @@ int zcip_main(int argc, char **argv)
// NOTE: the sequence of addresses we try changes only
// depending on when we detect conflicts.
{
uint32_t t = get_unaligned_u32p((uint32_t *) ((char *)&eth_addr + 2));
uint32_t t;
move_from_unaligned32(t, ((char *)&eth_addr + 2));
srand(t);
}
if (ip.s_addr == 0)

2
util-linux/volume_id/linux_raid.c
View File

@ -62,7 +62,7 @@ int volume_id_probe_linux_raid(struct volume_id *id, uint64_t off, uint64_t size
if (mdp->md_magic != cpu_to_le32(MD_MAGIC))
return -1;
memcpy(uuid, &mdp->set_uuid0, 4);
*(uint32_t*)uuid = mdp->set_uuid0;
memcpy(&uuid[4], &mdp->set_uuid1, 12);
volume_id_set_uuid(id, uuid, UUID_DCE);