new file mode 100644
--- /dev/null
+++ b/tests/test-isnand-nolibm.c
@@ -0,0 +1,78 @@
+/* Test of isnand() substitute.
+   Copyright (C) 2007-2008 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */
+
+#include <config.h>
+
+#include "isnand-nolibm.h"
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "nan.h"
+
+#define ASSERT(expr) \
+  do									     \
+    {									     \
+      if (!(expr))							     \
+        {								     \
+          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
+          fflush (stderr);						     \
+          abort ();							     \
+        }								     \
+    }									     \
+  while (0)
+
+int
+main ()
+{
+  /* Finite values.  */
+  ASSERT (!isnand (3.141));
+  ASSERT (!isnand (3.141e30));
+  ASSERT (!isnand (3.141e-30));
+  ASSERT (!isnand (-2.718));
+  ASSERT (!isnand (-2.718e30));
+  ASSERT (!isnand (-2.718e-30));
+  ASSERT (!isnand (0.0));
+  ASSERT (!isnand (-0.0));
+  /* Infinite values.  */
+  ASSERT (!isnand (1.0 / 0.0));
+  ASSERT (!isnand (-1.0 / 0.0));
+  /* Quiet NaN.  */
+  ASSERT (isnand (NaNd ()));
+#if defined DBL_EXPBIT0_WORD && defined DBL_EXPBIT0_BIT
+  /* Signalling NaN.  */
+  {
+    #define NWORDS \
+      ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
+    typedef union { double value; unsigned int word[NWORDS]; } memory_double;
+    memory_double m;
+    m.value = NaNd ();
+# if DBL_EXPBIT0_BIT > 0
+    m.word[DBL_EXPBIT0_WORD] ^= (unsigned int) 1 << (DBL_EXPBIT0_BIT - 1);
+# else
+    m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
+      ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
+# endif
+    m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
+      |= (unsigned int) 1 << DBL_EXPBIT0_BIT;
+    ASSERT (isnand (m.value));
+  }
+#endif
+  return 0;
+}