diff -up ./configure.in.orig ./configure.in
--- ./configure.in.orig	2013-03-26 18:11:42.574526209 +0000
+++ ./configure.in	2013-03-26 18:11:05.573049249 +0000
@@ -86,7 +86,7 @@ AC_PROG_LIBTOOL
 
 if test "$GCC" = "yes" ; then
   CFLAGS="$CFLAGS -O2"
-  AC_DEFINE([CP_HAS___BUILTIN_CLZ])
+  AC_DEFINE([CP_HAS___BUILTIN_CLZ], 1, [Define to 1 if you have the `__builtin_clz` function.])
 fi
 
 dnl -------------------------------------------------------------------------
@@ -103,19 +103,19 @@ dnl Checks for header files
 dnl -------------------------------------------------------------------------
 
 AC_HEADER_STDC
-AC_CHECK_HEADER(fcntl.h, AC_DEFINE([CP_HAS_FCNTL_H]), )
-AC_CHECK_HEADER(sys/time.h, AC_DEFINE([CP_HAS_SYS_TIME_H]), )
-AC_CHECK_HEADER(stdarg.h, AC_DEFINE([CP_HAS_STDARG_H]), )
-AC_CHECK_HEADER(unistd.h, AC_DEFINE([CP_HAS_UNISTD_H]), )
-AC_CHECK_HEADER(pthread.h, AC_DEFINE([CP_HAS_PTHREAD_H]), )
-AC_CHECK_HEADER(regex.h, AC_DEFINE([CP_HAS_REGEX_H]), )
-AC_CHECK_HEADER(sys/socket.h, AC_DEFINE([CP_HAS_SYS_SOCKET_H]), )
-AC_CHECK_HEADER(sys/select.h, AC_DEFINE([CP_HAS_SYS_SELECT_H]), )
-AC_CHECK_HEADER(arpa/inet.h, AC_DEFINE([CP_HAS_ARPA_INET_H]), )
-AC_CHECK_HEADER(netinet/in.h, AC_DEFINE([CP_HAS_NETINET_IN_H]), )
-AC_CHECK_HEADER(netdb.h, AC_DEFINE([CP_HAS_NETDB_H]), )
-AC_CHECK_HEADER(sys/poll.h, AC_DEFINE([CP_HAS_SYS_POLL_H]), )
-AC_CHECK_HEADER(dirent.h, AC_DEFINE([CP_HAS_DIRENT_H]), )
+AC_CHECK_HEADER(fcntl.h, AC_DEFINE([CP_HAS_FCNTL_H], 1, [Define to 1 if you have the <fcntl.h> header file.]), )
+AC_CHECK_HEADER(sys/time.h, AC_DEFINE([CP_HAS_SYS_TIME_H], 1, [Define to 1 if you have the <sys/time.h> header file.]), )
+AC_CHECK_HEADER(stdarg.h, AC_DEFINE([CP_HAS_STDARG_H], 1, [Define to 1 if you have the <stdarg.h> header file.]), )
+AC_CHECK_HEADER(unistd.h, AC_DEFINE([CP_HAS_UNISTD_H], 1, [Define to 1 if you have the <unistd.h> header file.]), )
+AC_CHECK_HEADER(pthread.h, AC_DEFINE([CP_HAS_PTHREAD_H], 1, [Define to 1 if you have the <pthread.h> header file.]), )
+AC_CHECK_HEADER(regex.h, AC_DEFINE([CP_HAS_REGEX_H], 1, [Define to 1 if you have the <regex.h> header file.]), )
+AC_CHECK_HEADER(sys/socket.h, AC_DEFINE([CP_HAS_SYS_SOCKET_H], 1, [Define to 1 if you have the <sys/socket.h> header file.]), )
+AC_CHECK_HEADER(sys/select.h, AC_DEFINE([CP_HAS_SYS_SELECT_H], 1, [Define to 1 if you have the <sys/select> header file.]), )
+AC_CHECK_HEADER(arpa/inet.h, AC_DEFINE([CP_HAS_ARPA_INET_H], 1, [Define to 1 if you have the <arpa/inet.h> header file.]), )
+AC_CHECK_HEADER(netinet/in.h, AC_DEFINE([CP_HAS_NETINET_IN_H], 1, [Define to 1 if you have the <netinet/in.h> header file.]), )
+AC_CHECK_HEADER(netdb.h, AC_DEFINE([CP_HAS_NETDB_H], 1, [Define to 1 if you have the <netdb.h> header file.]), )
+AC_CHECK_HEADER(sys/poll.h, AC_DEFINE([CP_HAS_SYS_POLL_H], 1, [Define to 1 if you have the <sys/poll.h> header file.]), )
+AC_CHECK_HEADER(dirent.h, AC_DEFINE([CP_HAS_DIRENT_H], 1, [Define to 1 if you have the <dirent.h> header file.]), )
 
 AC_CHECK_HEADER(dlfcn.h,[
 AC_DEFINE_UNQUOTED(CP_HAS_DLFCN_H, 1, [define if you have <dlfcn.h>])
@@ -272,41 +272,41 @@ AC_MSG_RESULT(no)
 AC_FUNC_MEMCMP
 AC_FUNC_STRFTIME
 AC_FUNC_VPRINTF
-AC_CHECK_FUNC(strstr, AC_DEFINE([CP_HAS_STRSTR]),)
-AC_CHECK_FUNC(memset, AC_DEFINE([CP_HAS_MEMSET]),)
-AC_CHECK_FUNC(strdup, AC_DEFINE([CP_HAS_STRDUP]),)
-AC_CHECK_FUNC(strndup, AC_DEFINE([CP_HAS_STRNDUP]),)
-AC_CHECK_FUNC(regcomp, AC_DEFINE([CP_HAS_REGCOMP]),)
-AC_CHECK_FUNC(strerror_r, AC_DEFINE([CP_HAS_STRERROR_R]),)
-AC_CHECK_FUNC(gettimeofday, AC_DEFINE([CP_HAS_GETTIMEOFDAY]),)
-AC_CHECK_FUNC(getopt, AC_DEFINE([CP_HAS_GETOPT]),)
-AC_CHECK_FUNC(dlopen, AC_DEFINE([CP_HAS_DLOPEN]),)
-AC_CHECK_FUNC(sigaction, AC_DEFINE([CP_HAS_SIGACTION]),)
-AC_CHECK_FUNC(read, AC_DEFINE([CP_HAS_READ]),)
-AC_CHECK_FUNC(write, AC_DEFINE([CP_HAS_WRITE]),)
-AC_CHECK_FUNC(socket, AC_DEFINE([CP_HAS_SOCKET]),)
-AC_CHECK_FUNC(select, AC_DEFINE([CP_HAS_SELECT]),)
-AC_CHECK_FUNC(poll, AC_DEFINE([CP_HAS_POLL]),)
-AC_CHECK_FUNC(inet_ntoa, AC_DEFINE([CP_HAS_INET_NTOA]),)
-AC_CHECK_FUNC(inet_ntop, AC_DEFINE([CP_HAS_INET_NTOP]),)
-AC_CHECK_FUNC(gethostname, AC_DEFINE([CP_HAS_GETHOSTNAME]),)
-AC_CHECK_FUNC(getaddrinfo, AC_DEFINE([CP_HAS_GETADDRINFO]),)
-AC_CHECK_FUNC(getcwd, AC_DEFINE([CP_HAS_GETCWD]),)
-AC_CHECK_FUNC(gmtime_r, AC_DEFINE([CP_HAS_GMTIME_R]),)
-AC_CHECK_FUNC(localtime_r, AC_DEFINE([CP_HAS_LOCALTIME_R]),)
-AC_CHECK_FUNC(pthread_getunique_np, AC_DEFINE([CP_HAS_PTHREAD_GETUNIQUE_NP]),)
-AC_CHECK_FUNC(random, AC_DEFINE([CP_HAS_RANDOM]),)
-AC_CHECK_FUNC(strlcat, AC_DEFINE([CP_HAS_STRLCAT]),)
-AC_CHECK_FUNC(strlcpy, AC_DEFINE([CP_HAS_STRLCPY]),)
-AC_CHECK_FUNC(snprintf, AC_DEFINE([CP_HAS_SNPRINTF]),)
-AC_CHECK_FUNC(vsprintf, AC_DEFINE([CP_HAS_VSPRINTF]),)
-AC_CHECK_FUNC(vsnprintf, AC_DEFINE([CP_HAS_VSNPRINTF]),)
-AC_CHECK_FUNC(strcasecmp, AC_DEFINE([CP_HAS_STRCASECMP]),)
-AC_CHECK_FUNC(strncasecmp, AC_DEFINE([CP_HAS_STRNCASECMP]),)
-AC_CHECK_FUNC(srandom, AC_DEFINE([CP_HAS_SRANDOM]),)
-AC_CHECK_FUNC(stat, AC_DEFINE([CP_HAS_STAT]),)
-AC_CHECK_FUNC(strptime, AC_DEFINE([CP_HAS_STRPTIME]),)
-AC_CHECK_FUNC(getpagesize, AC_DEFINE([CP_HAS_GETPAGESIZE]),)
+AC_CHECK_FUNC(strstr, AC_DEFINE([CP_HAS_STRSTR], 1, [Define to 1 if you have the `strstr' function.]), )
+AC_CHECK_FUNC(memset, AC_DEFINE([CP_HAS_MEMSET], 1, [Define to 1 if you have the `memset' function.]), )
+AC_CHECK_FUNC(strdup, AC_DEFINE([CP_HAS_STRDUP], 1, [Define to 1 if you have the `strdup' function.]), )
+AC_CHECK_FUNC(strndup, AC_DEFINE([CP_HAS_STRNDUP], 1, [Define to 1 if you have the `strndup' function.]), )
+AC_CHECK_FUNC(regcomp, AC_DEFINE([CP_HAS_REGCOMP], 1, [Define to 1 if you have the `regcomp' function.]), )
+AC_CHECK_FUNC(strerror_r, AC_DEFINE([CP_HAS_STRERROR_R], 1, [Define to 1 if you have the `strerror_r' function.]), )
+AC_CHECK_FUNC(gettimeofday, AC_DEFINE([CP_HAS_GETTIMEOFDAY], 1, [Define to 1 if you have the `gettimeofday' function.]), )
+AC_CHECK_FUNC(getopt, AC_DEFINE([CP_HAS_GETOPT], 1, [Define to 1 if you have the `getopt' function.]), )
+AC_CHECK_FUNC(dlopen, AC_DEFINE([CP_HAS_DLOPEN], 1, [Define to 1 if you have the `dlopen' function.]), )
+AC_CHECK_FUNC(sigaction, AC_DEFINE([CP_HAS_SIGACTION], 1, [Define to 1 if you have the `sigaction' function.]), )
+AC_CHECK_FUNC(read, AC_DEFINE([CP_HAS_READ], 1, [Define to 1 if you have the `read' function.]), )
+AC_CHECK_FUNC(write, AC_DEFINE([CP_HAS_WRITE], 1, [Define to 1 if you have the `write' function.]), )
+AC_CHECK_FUNC(socket, AC_DEFINE([CP_HAS_SOCKET], 1, [Define to 1 if you have the `socket' function.]), )
+AC_CHECK_FUNC(select, AC_DEFINE([CP_HAS_SELECT], 1, [Define to 1 if you have the `select' function.]), )
+AC_CHECK_FUNC(poll, AC_DEFINE([CP_HAS_POLL], 1, [Define to 1 if you have the `poll' function.]), )
+AC_CHECK_FUNC(inet_ntoa, AC_DEFINE([CP_HAS_INET_NTOA], 1, [Define to 1 if you have the `inet_ntoa' function.]), )
+AC_CHECK_FUNC(inet_ntop, AC_DEFINE([CP_HAS_INET_NTOP], 1, [Define to 1 if you have the `inet_ntop' function.]), )
+AC_CHECK_FUNC(gethostname, AC_DEFINE([CP_HAS_GETHOSTNAME], 1, [Define to 1 if you have the `gethostname' function.]), )
+AC_CHECK_FUNC(getaddrinfo, AC_DEFINE([CP_HAS_GETADDRINFO], 1, [Define to 1 if you have the `getaddrinfo' function.]), )
+AC_CHECK_FUNC(getcwd, AC_DEFINE([CP_HAS_GETCWD], 1, [Define to 1 if you have the `getcwd' function.]), )
+AC_CHECK_FUNC(gmtime_r, AC_DEFINE([CP_HAS_GMTIME_R], 1, [Define to 1 if you have the `gmtime_r' function.]), )
+AC_CHECK_FUNC(localtime_r, AC_DEFINE([CP_HAS_LOCALTIME_R], 1, [Define to 1 if you have the `localtime_r' function.]), )
+AC_CHECK_FUNC(pthread_getunique_np, AC_DEFINE([CP_HAS_PTHREAD_GETUNIQUE_NP], 1, [Define to 1 if you have the `pthread_getunique_np' function.]), )
+AC_CHECK_FUNC(random, AC_DEFINE([CP_HAS_RANDOM], 1, [Define to 1 if you have the `random' function.]), )
+AC_CHECK_FUNC(strlcat, AC_DEFINE([CP_HAS_STRLCAT], 1, [Define to 1 if you have the `strlcat' function.]), )
+AC_CHECK_FUNC(strlcpy, AC_DEFINE([CP_HAS_STRLCPY], 1, [Define to 1 if you have the `strlcopy' function.]), )
+AC_CHECK_FUNC(snprintf, AC_DEFINE([CP_HAS_SNPRINTF], 1, [Define to 1 if you have the `snprintf' function.]), )
+AC_CHECK_FUNC(vsprintf, AC_DEFINE([CP_HAS_VSPRINTF], 1, [Define to 1 if you have the `vsprintf' function.]), )
+AC_CHECK_FUNC(vsnprintf, AC_DEFINE([CP_HAS_VSNPRINTF], 1, [Define to 1 if you have the `vsnprintf' function.]), )
+AC_CHECK_FUNC(strcasecmp, AC_DEFINE([CP_HAS_STRCASECMP], 1, [Define to 1 if you have the `strcasecmp' function.]), )
+AC_CHECK_FUNC(strncasecmp, AC_DEFINE([CP_HAS_STRNCASECMP], 1, [Define to 1 if you have the `strncasecmp' function.]), )
+AC_CHECK_FUNC(srandom, AC_DEFINE([CP_HAS_SRANDOM], 1, [Define to 1 if you have the `srandom' function.]), )
+AC_CHECK_FUNC(stat, AC_DEFINE([CP_HAS_STAT], 1, [Define to 1 if you have the `stat' function.]), )
+AC_CHECK_FUNC(strptime, AC_DEFINE([CP_HAS_STRPTIME], 1, [Define to 1 if you have the `strptime' function.]), )
+AC_CHECK_FUNC(getpagesize, AC_DEFINE([CP_HAS_GETPAGESIZE], 1, [Define to 1 if you have the `getpagesize' function.]), )
 
 
 dnl -------------------------------------------------------------------------