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| author | Denys Vlasenko <vda.linux@googlemail.com> | 2024-05-31 12:01:43 +0200 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2024-05-31 16:03:23 +0200 |
| commit | 2075553a1b0eb843d4ee73a039b3e30bed9274e0 (patch) | |
| tree | 904f192fa9d7c920c9dde6a7bc26b208c3b03312 /networking/libiproute | |
| parent | 5a68a246e750359819d63bcff5ef97dd9c7788fc (diff) | |
| download | busybox-w32-2075553a1b0eb843d4ee73a039b3e30bed9274e0.tar.gz busybox-w32-2075553a1b0eb843d4ee73a039b3e30bed9274e0.tar.bz2 busybox-w32-2075553a1b0eb843d4ee73a039b3e30bed9274e0.zip | |
libbb: add bit counting function, use where appropriate
Although "naive" counting function is not too slow and is smaller,
using it on e.g. each of 1024 words of CPU mask feels wrong.
function old new delta
bb_popcnt_32 - 52 +52
get_prefix 323 321 -2
nproc_main 206 199 -7
d4_run_script 739 731 -8
ipcalc_main 533 507 -26
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 0/4 up/down: 52/-43) Total: 9 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'networking/libiproute')
| -rw-r--r-- | networking/libiproute/utils.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/networking/libiproute/utils.c b/networking/libiproute/utils.c index 4ce230356..3cce4a06e 100644 --- a/networking/libiproute/utils.c +++ b/networking/libiproute/utils.c | |||
| @@ -175,14 +175,13 @@ static void get_prefix_1(inet_prefix *dst, char *arg, int family) | |||
| 175 | if (netmask_pfx.family == AF_INET) { | 175 | if (netmask_pfx.family == AF_INET) { |
| 176 | /* fill in prefix length of dotted quad */ | 176 | /* fill in prefix length of dotted quad */ |
| 177 | uint32_t mask = ntohl(netmask_pfx.data[0]); | 177 | uint32_t mask = ntohl(netmask_pfx.data[0]); |
| 178 | uint32_t host = ~mask; | 178 | uint32_t inv = ~mask; |
| 179 | 179 | ||
| 180 | /* a valid netmask must be 2^n - 1 */ | 180 | /* a valid netmask must be 11..10..00 */ |
| 181 | if (host & (host + 1)) | 181 | if (inv & (inv + 1)) |
| 182 | goto bad; | 182 | goto bad; /* inv is not 00..01..11 */ |
| 183 | 183 | ||
| 184 | for (plen = 0; mask; mask <<= 1) | 184 | plen = bb_popcnt_32(mask); |
| 185 | ++plen; | ||
| 186 | if (plen > dst->bitlen) | 185 | if (plen > dst->bitlen) |
| 187 | goto bad; | 186 | goto bad; |
| 188 | /* dst->flags |= PREFIXLEN_SPECIFIED; */ | 187 | /* dst->flags |= PREFIXLEN_SPECIFIED; */ |