--- /dev/null
+/* Test for NaN that does not need libm.
+ Copyright (C) 2007 Free Software Foundation, Inc.
+
+ 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, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#if HAVE_ISNANL_IN_LIBC
+/* Get declaration of isnan macro or (older) isnanl function. */
+# include <math.h>
+# ifdef isnan
+# undef isnanl
+# define isnanl(x) isnan ((long double)(x))
+# endif
+#else
+/* Test whether X is a NaN. */
+# undef isnanl
+# define isnanl rpl_isnanl
+extern int isnanl (long double x);
+#endif