diff --git a/include/stdlib.h b/include/stdlib.h
index dcb83a5027..352339e859 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -203,6 +203,24 @@ libc_hidden_proto (strtoll)
 libc_hidden_proto (strtoul)
 libc_hidden_proto (strtoull)
 
+extern float __strtof_nan (const char *, char **, char) internal_function;
+extern double __strtod_nan (const char *, char **, char) internal_function;
+extern long double __strtold_nan (const char *, char **, char)
+     internal_function;
+extern float __wcstof_nan (const wchar_t *, wchar_t **, wchar_t)
+     internal_function;
+extern double __wcstod_nan (const wchar_t *, wchar_t **, wchar_t)
+     internal_function;
+extern long double __wcstold_nan (const wchar_t *, wchar_t **, wchar_t)
+     internal_function;
+
+libc_hidden_proto (__strtof_nan)
+libc_hidden_proto (__strtod_nan)
+libc_hidden_proto (__strtold_nan)
+libc_hidden_proto (__wcstof_nan)
+libc_hidden_proto (__wcstod_nan)
+libc_hidden_proto (__wcstold_nan)
+
 extern char *__ecvt (double __value, int __ndigit, int *__restrict __decpt,
 		     int *__restrict __sign);
 extern char *__fcvt (double __value, int __ndigit, int *__restrict __decpt,
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -52,6 +52,9 @@ extern unsigned long long int __wcstoull_internal (const wchar_t *
 						   __restrict __endptr,
 						   int __base,
 						   int __group) __THROW;
+extern unsigned long long int ____wcstoull_l_internal (const wchar_t *,
+						       wchar_t **, int, int,
+						       __locale_t);
 libc_hidden_proto (__wcstof_internal)
 libc_hidden_proto (__wcstod_internal)
 libc_hidden_proto (__wcstold_internal)
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -50,6 +50,7 @@ routines	:=							      \
 	strtol_l strtoul_l strtoll_l strtoull_l				      \
 	strtof strtod strtold						      \
 	strtof_l strtod_l strtold_l					      \
+	strtof_nan strtod_nan strtold_nan				      \
 	system canonicalize						      \
 	a64l l64a							      \
 	rpmatch strfmon strfmon_l getsubopt xpg_basename fmtmsg		      \
--- /dev/null
+++ b/stdlib/strtod_nan.c
@@ -0,0 +1,24 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow
+   strings, double.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <strtod_nan_narrow.h>
+#include <strtod_nan_double.h>
+
+#define STRTOD_NAN __strtod_nan
+#include <strtod_nan_main.c>
--- /dev/null
+++ b/stdlib/strtod_nan_double.h
@@ -0,0 +1,30 @@
+/* Convert string for NaN payload to corresponding NaN.  For double.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define FLOAT		double
+#define SET_MANTISSA(flt, mant)				\
+  do							\
+    {							\
+      union ieee754_double u;				\
+      u.d = (flt);					\
+      u.ieee_nan.mantissa0 = (mant) >> 32;		\
+      u.ieee_nan.mantissa1 = (mant);			\
+      if ((u.ieee.mantissa0 | u.ieee.mantissa1) != 0)	\
+	(flt) = u.d;					\
+    }							\
+  while (0)
--- /dev/null
+++ b/stdlib/strtod_nan_float.h
@@ -0,0 +1,29 @@
+/* Convert string for NaN payload to corresponding NaN.  For float.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define	FLOAT		float
+#define SET_MANTISSA(flt, mant)			\
+  do						\
+    {						\
+      union ieee754_float u;			\
+      u.f = (flt);				\
+      u.ieee_nan.mantissa = (mant);		\
+      if (u.ieee.mantissa != 0)			\
+	(flt) = u.f;				\
+    }						\
+  while (0)
--- /dev/null
+++ b/stdlib/strtod_nan_main.c
@@ -0,0 +1,63 @@
+/* Convert string for NaN payload to corresponding NaN.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <ieee754.h>
+#include <locale.h>
+#include <math.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+
+/* If STR starts with an optional n-char-sequence as defined by ISO C
+   (a sequence of ASCII letters, digits and underscores), followed by
+   ENDC, return a NaN whose payload is set based on STR.  Otherwise,
+   return a default NAN.  If ENDPTR is not NULL, set *ENDPTR to point
+   to the character after the initial n-char-sequence.  */
+
+internal_function
+FLOAT
+STRTOD_NAN (const STRING_TYPE *str, STRING_TYPE **endptr, STRING_TYPE endc)
+{
+  const STRING_TYPE *cp = str;
+
+  while ((*cp >= L_('0') && *cp <= L_('9'))
+	 || (*cp >= L_('A') && *cp <= L_('Z'))
+	 || (*cp >= L_('a') && *cp <= L_('z'))
+	 || *cp == L_('_'))
+    ++cp;
+
+  FLOAT retval = NAN;
+  if (*cp != endc)
+    goto out;
+
+  /* This is a system-dependent way to specify the bitmask used for
+     the NaN.  We expect it to be a number which is put in the
+     mantissa of the number.  */
+  STRING_TYPE *endp;
+  unsigned long long int mant;
+
+  mant = STRTOULL (str, &endp, 0);
+  if (endp == cp)
+    SET_MANTISSA (retval, mant);
+
+ out:
+  if (endptr != NULL)
+    *endptr = (STRING_TYPE *) cp;
+  return retval;
+}
+libc_hidden_def (STRTOD_NAN)
--- /dev/null
+++ b/stdlib/strtod_nan_narrow.h
@@ -0,0 +1,22 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow strings.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define STRING_TYPE char
+#define L_(Ch) Ch
+#define STRTOULL(S, E, B) ____strtoull_l_internal ((S), (E), (B), 0,	\
+						   _nl_C_locobj_ptr)
--- /dev/null
+++ b/stdlib/strtod_nan_wide.h
@@ -0,0 +1,22 @@
+/* Convert string for NaN payload to corresponding NaN.  Wide strings.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define STRING_TYPE wchar_t
+#define L_(Ch) L##Ch
+#define STRTOULL(S, E, B) ____wcstoull_l_internal ((S), (E), (B), 0,	\
+						   _nl_C_locobj_ptr)
--- /dev/null
+++ b/stdlib/strtof_nan.c
@@ -0,0 +1,24 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow
+   strings, float.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <strtod_nan_narrow.h>
+#include <strtod_nan_float.h>
+
+#define STRTOD_NAN __strtof_nan
+#include <strtod_nan_main.c>
--- /dev/null
+++ b/stdlib/strtold_nan.c
@@ -0,0 +1,30 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow
+   strings, long double.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+
+/* This function is unused if long double and double have the same
+   representation.  */
+#ifndef __NO_LONG_DOUBLE_MATH
+# include <strtod_nan_narrow.h>
+# include <strtod_nan_ldouble.h>
+
+# define STRTOD_NAN __strtold_nan
+# include <strtod_nan_main.c>
+#endif
--- a/wcsmbs/Makefile
+++ b/wcsmbs/Makefile
@@ -33,6 +33,7 @@ routines := wcscat wcschr wcscmp wcscpy wcscspn wcsdup wcslen wcsncat \
 	    wcstol wcstoul wcstoll wcstoull wcstod wcstold wcstof \
 	    wcstol_l wcstoul_l wcstoll_l wcstoull_l \
 	    wcstod_l wcstold_l wcstof_l \
+	    wcstod_nan wcstold_nan wcstof_nan \
 	    wcscoll wcsxfrm \
 	    wcwidth wcswidth \
 	    wcscoll_l wcsxfrm_l \
--- a/wcsmbs/wcstod_l.c
+++ b/wcsmbs/wcstod_l.c
@@ -23,9 +23,6 @@
 
 extern double ____wcstod_l_internal (const wchar_t *, wchar_t **, int,
 				     __locale_t);
-extern unsigned long long int ____wcstoull_l_internal (const wchar_t *,
-						       wchar_t **, int, int,
-						       __locale_t);
 
 #define	USE_WIDE_CHAR	1
 
--- /dev/null
+++ b/wcsmbs/wcstod_nan.c
@@ -0,0 +1,23 @@
+/* Convert string for NaN payload to corresponding NaN.  Wide strings, double.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "../stdlib/strtod_nan_wide.h"
+#include "../stdlib/strtod_nan_double.h"
+
+#define STRTOD_NAN __wcstod_nan
+#include "../stdlib/strtod_nan_main.c"
--- a/wcsmbs/wcstof_l.c
+++ b/wcsmbs/wcstof_l.c
@@ -25,8 +25,5 @@
 
 extern float ____wcstof_l_internal (const wchar_t *, wchar_t **, int,
 				    __locale_t);
-extern unsigned long long int ____wcstoull_l_internal (const wchar_t *,
-						       wchar_t **, int, int,
-						       __locale_t);
 
 #include <stdlib/strtof_l.c>
--- /dev/null
+++ b/wcsmbs/wcstof_nan.c
@@ -0,0 +1,23 @@
+/* Convert string for NaN payload to corresponding NaN.  Wide strings, float.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "../stdlib/strtod_nan_wide.h"
+#include "../stdlib/strtod_nan_float.h"
+
+#define STRTOD_NAN __wcstof_nan
+#include "../stdlib/strtod_nan_main.c"
--- a/wcsmbs/wcstold_l.c
+++ b/wcsmbs/wcstold_l.c
@@ -24,8 +24,5 @@
 
 extern long double ____wcstold_l_internal (const wchar_t *, wchar_t **, int,
 					   __locale_t);
-extern unsigned long long int ____wcstoull_l_internal (const wchar_t *,
-						       wchar_t **, int, int,
-						       __locale_t);
 
 #include <strtold_l.c>
--- /dev/null
+++ b/wcsmbs/wcstold_nan.c
@@ -0,0 +1,30 @@
+/* Convert string for NaN payload to corresponding NaN.  Wide strings,
+   long double.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+
+/* This function is unused if long double and double have the same
+   representation.  */
+#ifndef __NO_LONG_DOUBLE_MATH
+# include "../stdlib/strtod_nan_wide.h"
+# include <strtod_nan_ldouble.h>
+
+# define STRTOD_NAN __wcstold_nan
+# include "../stdlib/strtod_nan_main.c"
+#endif