Add bitpop16() in util.c.

common/util.c

@@ -30,6 +30,14 @@ uint8_t bitpop(uint8_t bits)
 */
 }
 
+uint8_t bitpop16(uint16_t bits)
+{
+    uint8_t c;
+    for (c = 0; bits; c++)
+        bits &= bits - 1;
+    return c;
+}
+
 // most significant on-bit - return highest location of on-bit
 uint8_t biton(uint8_t bits)
 {

common/util.h

@@ -16,7 +16,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #ifndef UTIL_H
-#define UTIL_H 1
+#define UTIL_H
 
 #include <stdint.h>
 
@@ -29,6 +29,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
 uint8_t bitpop(uint8_t bits);
+uint8_t bitpop16(uint16_t bits);
 uint8_t biton(uint8_t bits);
 
 #endif