diff --git a/tools/ant-cl/plot-diag b/tools/ant-cl/plot-diag
new file mode 100755
index 0000000..629f755
--- /dev/null
+++ b/tools/ant-cl/plot-diag
@@ -0,0 +1,22 @@
+#!/bin/sh
+#
+# tools/ant-cl/plot-diag - Plot the output of  ant-cl -D >file
+#
+# Written 2012 by Werner Almesberger
+# Copyright 2012 Werner Almesberger
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+
+if [ -z "$1" -o ! -r "$1" ]; then
+	echo "usage: $0 file" 1>&2
+	exit 1
+fi
+gnuplot -p \
+    -e 'set style data lines' \
+    -e 'unset key' \
+    -e "plot '$1' using 0:2, '$1' using 0:3, '$1' using 0:4, '$1' using 0:5,
+   '$1' using 0:2 with impulses lt 7'"