[haiku-commits] r40360 - haiku/trunk/src/kits/network/libnetapi
- From: kallisti5@xxxxxxxxxxx
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Sat, 5 Feb 2011 00:32:58 +0100 (CET)
Author: kallisti5
Date: 2011-02-05 00:32:58 +0100 (Sat, 05 Feb 2011)
New Revision: 40360
Changeset: http://dev.haiku-os.org/changeset/40360
Modified:
haiku/trunk/src/kits/network/libnetapi/NetworkAddress.cpp
Log:
added optimized gcc builtin bit population count as per Axel's recommendation;
the optimized function might be used for the ipv6 netmask length as well.. i
just don't want to touch that double for loop without *LOTS* of testing; lets
hope this isn't my first build-breaker
Modified: haiku/trunk/src/kits/network/libnetapi/NetworkAddress.cpp
===================================================================
--- haiku/trunk/src/kits/network/libnetapi/NetworkAddress.cpp 2011-02-04
22:42:56 UTC (rev 40359)
+++ haiku/trunk/src/kits/network/libnetapi/NetworkAddress.cpp 2011-02-04
23:32:58 UTC (rev 40360)
@@ -17,6 +17,26 @@
#include <sys/sockio.h>
+/* The GCC builtin below only exists in > GCC 3.4
+ * Benefits include faster execution time as the builtin
+ * uses a bitcounting cpu instruction if it exists
+ */
+#if __GNUC__ >= 4
+# define BitCount(buffer) __builtin_popcount(buffer)
+#else
+ssize_t BitCount(uint32 buf)
+{
+ ssize_t result = 0;
+ for (uint8 i = 32; i > 0; i--) {
+ if ((buf & (1 << (i - 1))) == 0)
+ break;
+ result++;
+ }
+ return result;
+}
+#endif
+
+
static uint8
from_hex(char hex)
{
@@ -763,21 +783,15 @@
{
sockaddr_in& mask = (sockaddr_in&)fAddress;
- ssize_t result = 0;
uint32 hostMask = ntohl(mask.sin_addr.s_addr);
- for (uint8 i = 32; i > 0; i--) {
- if ((hostMask & (1 << (i - 1))) == 0)
- break;
- result++;
- }
-
- return result;
+ return BitCount(hostMask);
}
case AF_INET6:
{
sockaddr_in6& mask = (sockaddr_in6&)fAddress;
+ // TODO : see if we can use the optimized BitCount for
this
ssize_t result = 0;
for (uint8 i = 0; i < sizeof(in6_addr); i++) {
for (uint8 j = 0; j < 8; j++) {
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