rm -f Makefile.tem
else
- if test x"$enable_sim_filter" != x"yes"; then
+ if test x"$enable_sim_filter" != x"yes" -a x"$enable_sim_filter" != x""; then
mv Makefile Makefile.tem
echo "Setting IGEN_FILTER= -f $enable_sim_filter" 1>&6
sed -e "s/^IGEN_FILTER.*=.*\$/IGEN_FILTER = -f $enable_sim_filter/" \