1 files changed, 47 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_nan.c b/sysdeps/libm-ieee754/s_nan.c
new file mode 100644
index 0000000000..58551c1ad5
--- /dev/null
+++ b/sysdeps/libm-ieee754/s_nan.c
@@ -0,0 +1,47 @@
+/* Return quiet nan.
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* XXX The ISO C 9X standard mentions a `n-char-sequence' which is provided
+   as the argument to this function but I have no clue what this means.
+   Perhaps it is a description of the bits set in the mantissa.  */
+#include <math.h>
+#ifdef HANDLE_TAGP
+# include <stdlib.h>
+# include <string.h>
+#else
+# include <ieee754.h>
+#endif
+
+
+double
+nan (const char *tagp)
+{
+#ifdef HANDLE_TAGP
+  /* If we ever should have use of the TAGP parameter we will use the
+     strtod function to analyze it.  */
+  char buf[6 + strlen (tagp)];
+  sprintf (buf, "NAN(%s)", tagp);
+  return strtod (buf, NULL);
+#else
+  static const union ieee754_double nan_value =
+  { ieee: { mantissa1: 0x1, mantissa0: 0x0, exponent: 0x7ff, negative: 0 } };
+  return nan_value.d;
+#endif
+}