--- nono/configure.ac	2026/04/29 17:05:26	1.1.1.15
+++ nono/configure.ac	2026/04/29 17:05:34	1.1.1.16
@@ -286,6 +286,28 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],
 		AC_MSG_RESULT(no)
 	])
 
+AC_MSG_CHECKING(for __builtin_bitreverse16)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],
+	[[
+		return __builtin_bitreverse16(1);
+	]])], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE___BUILTIN_BITREVERSE16)
+	], [
+		AC_MSG_RESULT(no)
+	])
+
+AC_MSG_CHECKING(for __builtin_bitreverse32)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],
+	[[
+		return __builtin_bitreverse32(1);
+	]])], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE___BUILTIN_BITREVERSE32)
+	], [
+		AC_MSG_RESULT(no)
+	])
+
 AC_MSG_CHECKING(for __builtin_bswap16)
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],
 	[[
@@ -1007,6 +1029,32 @@ AC_CHECK_LIB(z, gzclose,
 *** If use use Ubuntu, sudo apt install zlib1g-dev])]
 )
 
+# libslirp
+AC_ARG_WITH([libslirp],
+	[AS_HELP_STRING([--without-libslirp],
+		[disable usermode network (using SLIRP)])],
+	[],
+	[with_libslirp=yes])
+
+AS_IF([test "x$with_libslirp" != "xno"], [
+	CHECK_LIB([libslirp], [-lslirp], [
+		#include <slirp/libslirp.h>
+	], [
+		slirp_version_string();
+	])
+	if test x"${has_libslirp}" = x"yes"; then
+		AC_DEFINE([HAVE_HOSTNET_SLIRP])
+		AC_SUBST([HOSTNET_SLIRP], [yes])
+	else
+		AC_MSG_ERROR([*** libslirp is not found.
+*** If use use pkgsrc, install net/libslirp.
+*** If you use Ubuntu, sudo apt install libslirp-dev.
+*** Or specify --without-libslirp (it disables hostnet-driver=usermode).])
+	fi
+], [
+	AC_SUBST([HOSTNET_SLIRP], [no])
+])
+
 # wxWidgets
 AC_ARG_WITH([gui],
 	[AS_HELP_STRING([--without-gui], [disable GUI support])],
@@ -1070,7 +1118,15 @@ AS_IF([test "x$with_gui" != xno], [
 
 # nono 本体のチェックはここまで。
 nono_CPPFLAGS=${CPPFLAGS}
-nono_LIBS=${LIBS}
+case "${host_os}" in
+ netbsd*)
+	# どうしたもんかこれ。
+	nono_LIBS=[`echo ${LIBS} | sed -e 's/-L\([^ ]*\) /-L\1 -Wl,-R,\1 /'`]
+	;;
+ *)
+	nono_LIBS=${LIBS}
+	;;
+esac
 AC_SUBST([NONO_CPPFLAGS], [${nono_CPPFLAGS}])
 AC_SUBST([NONO_LIBS], [${nono_LIBS}])