disable unused result warnings when possible
diff --git a/configure.in b/configure.in
index 315a832..d5f00b2 100644
--- a/configure.in
+++ b/configure.in
@@ -981,6 +981,28 @@
       BASECFLAGS="$BASECFLAGS -fno-strict-aliasing"
     fi
 
+    AC_MSG_CHECKING(if we can turn off $CC unused result warning)
+     ac_save_cc="$CC"
+     CC="$CC -Wunused-result -Werror"
+     save_CFLAGS="$CFLAGS"
+     AC_CACHE_VAL(ac_cv_disable_unused_result_warning,
+       AC_COMPILE_IFELSE(
+         [
+	   AC_LANG_PROGRAM([[]], [[]])
+	 ],[
+           ac_cv_disable_unused_result_warning=yes
+	 ],[
+           ac_cv_disable_unused_result_warning=no
+	 ]))
+     CFLAGS="$save_CFLAGS"
+     CC="$ac_save_cc"
+    AC_MSG_RESULT($ac_cv_disable_unused_result_warning)
+
+    if test $ac_cv_disable_unused_result_warning = yes
+    then
+      BASECFLAGS="$BASECFLAGS -Wno-unused-result"
+    fi
+
     # if using gcc on alpha, use -mieee to get (near) full IEEE 754
     # support.  Without this, treatment of subnormals doesn't follow
     # the standard.