From: Tom Gundersen <teg@jklm.no>
Date: Thu, 30 Jan 2014 16:23:34 +0000 (+0100)
Subject: shared: net - use u32ctz to compute prefixlen
X-Git-Tag: v209~278
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=ba91431154ad7bac82ddf0a540ec1b40db62d782;p=elogind.git

shared: net - use u32ctz to compute prefixlen
---

diff --git a/src/shared/net-util.c b/src/shared/net-util.c
index 630be18e5..ba21ae437 100644
--- a/src/shared/net-util.c
+++ b/src/shared/net-util.c
@@ -59,18 +59,9 @@ bool net_match_config(const struct ether_addr *match_mac,
 }
 
 unsigned net_netmask_to_prefixlen(const struct in_addr *addr) {
-        unsigned len = 0;
-        uint32_t mask;
-
         assert(addr);
 
-        mask = be32toh(addr->s_addr);
-        while (mask) {
-                len++;
-                mask = mask << 1;
-        }
-
-        return len;
+        return 32 - u32ctz(be32toh(addr->s_addr));
 }
 
 int config_parse_ifname(const char *unit,