diff --git a/NEWS b/NEWS
index 23051cf139..77635d5760 100644
--- a/NEWS
+++ b/NEWS
@@ -21,6 +21,13 @@ Major new features:
 
 * PRIb* and PRIB* macros from C2X have been added to <inttypes.h>.
 
+* printf-family functions now support the wN format length modifiers for
+  arguments of type intN_t, int_leastN_t, uintN_t or uint_leastN_t (for
+  example, %w32d to print int32_t or int_least32_t in decimal, or %w32x
+  to print uint32_t or uint_least32_t in hexadecimal) and the wfN format
+  length modifiers for arguments of type int_fastN_t or uint_fastN_t, as
+  specified in draft ISO C2X.
+
 * A new tunable, glibc.pthread.stack_hugetlb, can be used to disable
   Transparent Huge Pages (THP) in stack allocation at pthread_create.
 
diff --git a/manual/stdio.texi b/manual/stdio.texi
index 3820a24f3e..a981e6512a 100644
--- a/manual/stdio.texi
+++ b/manual/stdio.texi
@@ -2028,6 +2028,24 @@ Specifies that the argument is a @code{ptrdiff_t}.
 
 This modifier was introduced in @w{ISO C99}.
 
+@item w@var{n}
+Specifies that the argument is a @code{int@var{n}_t} or
+@code{int_least@var{n}_t} (which are the same type), for conversions
+taking signed integers, or @code{uint@var{n}_t} or
+@code{uint_least@var{n}_t} (which are the same type), for conversions
+taking unsigned integers.  If the type is narrower than @code{int},
+the promoted argument is converted back to the specified type.
+
+This modifier was introduced in @w{ISO C2X}.
+
+@item wf@var{n}
+Specifies that the argument is a @code{int_fast@var{n}_t} or
+@code{uint_fast@var{n}_t}, as appropriate.  If the type is narrower
+than @code{int}, the promoted argument is converted back to the
+specified type.
+
+This modifier was introduced in @w{ISO C2X}.
+
 @item z
 @itemx Z
 Specifies that the argument is a @code{size_t}.
diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index 4c15b97683..8871ec7668 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -219,6 +219,7 @@ tests := \
   tst-printf-bz25691 \
   tst-printf-fp-free \
   tst-printf-fp-leak \
+  tst-printf-intn \
   tst-printf-oct \
   tst-printf-round \
   tst-printfsz \
diff --git a/stdio-common/printf-parse.h b/stdio-common/printf-parse.h
index b25181496c..57673a331d 100644
--- a/stdio-common/printf-parse.h
+++ b/stdio-common/printf-parse.h
@@ -93,14 +93,17 @@ __find_specwc (const unsigned int *format)
    with the parsed details.  POSN is the number of arguments already
    consumed.  At most MAXTYPES - POSN types are filled in TYPES.  Return
    the number of args consumed by this spec; *MAX_REF_ARG is updated so it
-   remains the highest argument index used.  */
+   remains the highest argument index used.  *FAILED is set to indicate
+   whether parsing failed and printf should return with an error status.  */
 extern size_t __parse_one_specmb (const unsigned char *format, size_t posn,
 				  struct printf_spec *spec,
-				  size_t *max_ref_arg) attribute_hidden;
+				  size_t *max_ref_arg,
+				  bool *failed) attribute_hidden;
 
 extern size_t __parse_one_specwc (const unsigned int *format, size_t posn,
 				  struct printf_spec *spec,
-				  size_t *max_ref_arg) attribute_hidden;
+				  size_t *max_ref_arg,
+				  bool *failed) attribute_hidden;
 
 
 
diff --git a/stdio-common/printf-parsemb.c b/stdio-common/printf-parsemb.c
index c5d2704b02..414cbc7223 100644
--- a/stdio-common/printf-parsemb.c
+++ b/stdio-common/printf-parsemb.c
@@ -56,14 +56,17 @@ size_t
 attribute_hidden
 #ifdef COMPILE_WPRINTF
 __parse_one_specwc (const UCHAR_T *format, size_t posn,
-		    struct printf_spec *spec, size_t *max_ref_arg)
+		    struct printf_spec *spec, size_t *max_ref_arg,
+		    bool *failed)
 #else
 __parse_one_specmb (const UCHAR_T *format, size_t posn,
-		    struct printf_spec *spec, size_t *max_ref_arg)
+		    struct printf_spec *spec, size_t *max_ref_arg,
+		    bool *failed)
 #endif
 {
   unsigned int n;
   size_t nargs = 0;
+  bool is_fast;
 
   /* Skip the '%'.  */
   ++format;
@@ -81,6 +84,8 @@ __parse_one_specmb (const UCHAR_T *format, size_t posn,
   spec->info.wide = sizeof (UCHAR_T) > 1;
   spec->info.is_binary128 = 0;
 
+  *failed = false;
+
   /* Test for positional argument.  */
   if (ISDIGIT (*format))
     {
@@ -298,6 +303,53 @@ __parse_one_specmb (const UCHAR_T *format, size_t posn,
 #endif
 	spec->info.is_long = sizeof (uintmax_t) > sizeof (unsigned int);
 	break;
+      case L_('w'):
+	is_fast = false;
+	if (*format == L_('f'))
+	  {
+	    ++format;
+	    is_fast = true;
+	  }
+	int bitwidth = 0;
+	if (ISDIGIT (*format))
+	  bitwidth = read_int (&format);
+	if (is_fast)
+	  switch (bitwidth)
+	    {
+	    case 8:
+	      bitwidth = INT_FAST8_WIDTH;
+	      break;
+	    case 16:
+	      bitwidth = INT_FAST16_WIDTH;
+	      break;
+	    case 32:
+	      bitwidth = INT_FAST32_WIDTH;
+	      break;
+	    case 64:
+	      bitwidth = INT_FAST64_WIDTH;
+	      break;
+	    }
+	switch (bitwidth)
+	  {
+	  case 8:
+	    spec->info.is_char = 1;
+	    break;
+	  case 16:
+	    spec->info.is_short = 1;
+	    break;
+	  case 32:
+	    break;
+	  case 64:
+	    spec->info.is_long_double = 1;
+	    spec->info.is_long = 1;
+	    break;
+	  default:
+	    /* ISO C requires this error to be detected.  */
+	    __set_errno (EINVAL);
+	    *failed = true;
+	    break;
+	  }
+	break;
       default:
 	/* Not a recognized modifier.  Backup.  */
 	--format;
diff --git a/stdio-common/printf-prs.c b/stdio-common/printf-prs.c
index 2408a2e328..9d8bf306e4 100644
--- a/stdio-common/printf-prs.c
+++ b/stdio-common/printf-prs.c
@@ -63,6 +63,7 @@ parse_printf_format (const char *fmt, size_t n, int *argtypes)
   size_t max_ref_arg;		/* Highest index used in a positional arg.  */
   struct printf_spec spec;
   const unsigned char *f = (const unsigned char *) fmt;
+  bool failed;
 
   nargs = 0;
   max_ref_arg = 0;
@@ -71,7 +72,7 @@ parse_printf_format (const char *fmt, size_t n, int *argtypes)
   for (f = __find_specmb (f); *f != '\0'; f = spec.next_fmt)
     {
       /* Parse this spec.  */
-      nargs += __parse_one_specmb (f, nargs, &spec, &max_ref_arg);
+      nargs += __parse_one_specmb (f, nargs, &spec, &max_ref_arg, &failed);
 
       /* If the width is determined by an argument, it is an int.  */
       if (spec.width_arg != -1 && (size_t) spec.width_arg < n)
diff --git a/stdio-common/tst-printf-intn-main.c b/stdio-common/tst-printf-intn-main.c
new file mode 100644
index 0000000000..3c311de81c
--- /dev/null
+++ b/stdio-common/tst-printf-intn-main.c
@@ -0,0 +1,619 @@
+/* Test printf formats for intN_t, int_leastN_t and int_fastN_t types.
+   Copyright (C) 2023 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <inttypes.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <wchar.h>
+
+#include <libc-diag.h>
+#include <support/check.h>
+
+/* GCC does not know the %wN or %wfN length modifiers before GCC 13.  */
+DIAG_PUSH_NEEDS_COMMENT;
+#if !__GNUC_PREREQ (13, 0)
+DIAG_IGNORE_NEEDS_COMMENT (12, "-Wformat");
+DIAG_IGNORE_NEEDS_COMMENT (12, "-Wformat-extra-args");
+#endif
+
+#define CHECK_PRINTF(EXPECTED, FMT, ...)				\
+  do									\
+    {									\
+      int ret = SNPRINTF (buf, sizeof buf / sizeof buf[0], L_(FMT),	\
+			  __VA_ARGS__);					\
+      TEST_COMPARE_STRING_MACRO (buf, L_(EXPECTED));			\
+      TEST_COMPARE (ret, STRLEN (L_(EXPECTED)));			\
+    }									\
+  while (0)
+
+#define CHECK_PRINTF_ERR(FMT, ...)					\
+  do									\
+    {									\
+      int ret = SNPRINTF (buf, sizeof buf / sizeof buf[0], L_(FMT),	\
+			  __VA_ARGS__);					\
+      TEST_VERIFY (ret < 0);						\
+    }									\
+  while (0)
+
+static void
+test_w8 (void)
+{
+  CHAR buf[1024];
+  int8_t n;
+  int_least8_t ln;
+  CHECK_PRINTF ("123", "%w8d", (int8_t) 123);
+  CHECK_PRINTF ("-123", "%w8d", (int8_t) -123);
+  CHECK_PRINTF ("123", "%w8i", (int8_t) 123);
+  CHECK_PRINTF ("-123", "%w8i", (int8_t) -123);
+  CHECK_PRINTF ("1111011", "%w8b", (uint8_t) 123);
+  CHECK_PRINTF ("1111011", "%w8B", (uint8_t) 123);
+  CHECK_PRINTF ("173", "%w8o", (uint8_t) 123);
+  CHECK_PRINTF ("123", "%w8u", (uint8_t) 123);
+  CHECK_PRINTF ("7b", "%w8x", (uint8_t) 123);
+  CHECK_PRINTF ("7B", "%w8X", (uint8_t) 123);
+  CHECK_PRINTF ("  123", "%5w8d", (int8_t) 123);
+  CHECK_PRINTF ("  123", "%*w8d", 5, (int8_t) 123);
+  CHECK_PRINTF ("0x7b", "%#w8x", (uint8_t) 123);
+  CHECK_PRINTF ("00123", "%.5w8d", (int8_t) 123);
+  CHECK_PRINTF ("00123", "%.*w8d", 5, (int8_t) 123);
+  CHECK_PRINTF ("   00123", "%8.5w8d", (int8_t) 123);
+  CHECK_PRINTF ("   00123", "%*.5w8d", 8, (int8_t) 123);
+  CHECK_PRINTF ("   00123", "%8.*w8d", 5, (int8_t) 123);
+  CHECK_PRINTF ("   00123", "%*.*w8d", 8, 5, (int8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-8.5w8d", (int8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-*.5w8d", 8, (int8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-8.*w8d", 5, (int8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-*.*w8d", 8, 5, (int8_t) 123);
+  n = -1;
+  CHECK_PRINTF ("12345", "%d%w8n", 12345, &n);
+  TEST_COMPARE (n, 5);
+  CHECK_PRINTF ("123", "%w8d", (int_least8_t) 123);
+  CHECK_PRINTF ("-123", "%w8d", (int_least8_t) -123);
+  CHECK_PRINTF ("123", "%w8i", (int_least8_t) 123);
+  CHECK_PRINTF ("-123", "%w8i", (int_least8_t) -123);
+  CHECK_PRINTF ("1111011", "%w8b", (uint_least8_t) 123);
+  CHECK_PRINTF ("1111011", "%w8B", (uint_least8_t) 123);
+  CHECK_PRINTF ("173", "%w8o", (uint_least8_t) 123);
+  CHECK_PRINTF ("123", "%w8u", (uint_least8_t) 123);
+  CHECK_PRINTF ("7b", "%w8x", (uint_least8_t) 123);
+  CHECK_PRINTF ("7B", "%w8X", (uint_least8_t) 123);
+  CHECK_PRINTF ("  123", "%5w8d", (int_least8_t) 123);
+  CHECK_PRINTF ("  123", "%*w8d", 5, (int_least8_t) 123);
+  CHECK_PRINTF ("0x7b", "%#w8x", (uint_least8_t) 123);
+  CHECK_PRINTF ("00123", "%.5w8d", (int_least8_t) 123);
+  CHECK_PRINTF ("00123", "%.*w8d", 5, (int_least8_t) 123);
+  CHECK_PRINTF ("   00123", "%8.5w8d", (int_least8_t) 123);
+  CHECK_PRINTF ("   00123", "%*.5w8d", 8, (int_least8_t) 123);
+  CHECK_PRINTF ("   00123", "%8.*w8d", 5, (int_least8_t) 123);
+  CHECK_PRINTF ("   00123", "%*.*w8d", 8, 5, (int_least8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-8.5w8d", (int_least8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-*.5w8d", 8, (int_least8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-8.*w8d", 5, (int_least8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-*.*w8d", 8, 5, (int_least8_t) 123);
+  ln = -1;
+  CHECK_PRINTF ("12345", "%d%w8n", 12345, &ln);
+  TEST_COMPARE (ln, 5);
+  /* Test truncation of value in promoted type not representable in
+     narrower type.  */
+  CHECK_PRINTF ("57", "%w8d", 12345);
+  CHECK_PRINTF ("-57", "%w8d", -12345);
+  CHECK_PRINTF ("-121", "%w8d", 1234567);
+  CHECK_PRINTF ("121", "%w8d", -1234567);
+  CHECK_PRINTF ("135", "%w8u", 1234567);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 10 test2 20", "%4$s %3$w8d %2$s %1$w8d",
+		276, "test2", 266, "test");
+}
+
+static void
+test_wf8 (void)
+{
+  CHAR buf[1024];
+  int_fast8_t n;
+  _Static_assert (sizeof (int_fast8_t) == sizeof (char),
+		  "test assumes size of int_fast8_t");
+  CHECK_PRINTF ("123", "%wf8d", (int_fast8_t) 123);
+  CHECK_PRINTF ("-123", "%wf8d", (int_fast8_t) -123);
+  CHECK_PRINTF ("123", "%wf8i", (int_fast8_t) 123);
+  CHECK_PRINTF ("-123", "%wf8i", (int_fast8_t) -123);
+  CHECK_PRINTF ("1111011", "%wf8b", (uint_fast8_t) 123);
+  CHECK_PRINTF ("1111011", "%wf8B", (uint_fast8_t) 123);
+  CHECK_PRINTF ("173", "%wf8o", (uint_fast8_t) 123);
+  CHECK_PRINTF ("123", "%wf8u", (uint_fast8_t) 123);
+  CHECK_PRINTF ("7b", "%wf8x", (uint_fast8_t) 123);
+  CHECK_PRINTF ("7B", "%wf8X", (uint_fast8_t) 123);
+  CHECK_PRINTF ("  123", "%5w8d", (int_fast8_t) 123);
+  CHECK_PRINTF ("  123", "%*w8d", 5, (int_fast8_t) 123);
+  CHECK_PRINTF ("0x7b", "%#w8x", (uint_fast8_t) 123);
+  CHECK_PRINTF ("00123", "%.5w8d", (int_fast8_t) 123);
+  CHECK_PRINTF ("00123", "%.*w8d", 5, (int_fast8_t) 123);
+  CHECK_PRINTF ("   00123", "%8.5w8d", (int_fast8_t) 123);
+  CHECK_PRINTF ("   00123", "%*.5w8d", 8, (int_fast8_t) 123);
+  CHECK_PRINTF ("   00123", "%8.*w8d", 5, (int_fast8_t) 123);
+  CHECK_PRINTF ("   00123", "%*.*w8d", 8, 5, (int_fast8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-8.5w8d", (int_fast8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-*.5w8d", 8, (int_fast8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-8.*w8d", 5, (int_fast8_t) 123);
+  CHECK_PRINTF ("00123   ", "%-*.*w8d", 8, 5, (int_fast8_t) 123);
+  n = -1;
+  CHECK_PRINTF ("12345", "%d%wf8n", 12345, &n);
+  TEST_COMPARE (n, 5);
+  /* Test truncation of value in promoted type not representable in
+     narrower type.  */
+  CHECK_PRINTF ("57", "%wf8d", 12345);
+  CHECK_PRINTF ("-57", "%wf8d", -12345);
+  CHECK_PRINTF ("-121", "%wf8d", 1234567);
+  CHECK_PRINTF ("121", "%wf8d", -1234567);
+  CHECK_PRINTF ("135", "%wf8u", 1234567);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 10 test2 20", "%4$s %3$wf8d %2$s %1$wf8d",
+		276, "test2", 266, "test");
+}
+
+static void
+test_w16 (void)
+{
+  CHAR buf[1024];
+  int16_t n;
+  int_least16_t ln;
+  CHECK_PRINTF ("12345", "%w16d", (int16_t) 12345);
+  CHECK_PRINTF ("-12345", "%w16d", (int16_t) -12345);
+  CHECK_PRINTF ("12345", "%w16i", (int16_t) 12345);
+  CHECK_PRINTF ("-12345", "%w16i", (int16_t) -12345);
+  CHECK_PRINTF ("11000000111001", "%w16b", (uint16_t) 12345);
+  CHECK_PRINTF ("11000000111001", "%w16B", (uint16_t) 12345);
+  CHECK_PRINTF ("30071", "%w16o", (uint16_t) 12345);
+  CHECK_PRINTF ("12345", "%w16u", (uint16_t) 12345);
+  CHECK_PRINTF ("303a", "%w16x", (uint16_t) 12346);
+  CHECK_PRINTF ("303A", "%w16X", (uint16_t) 12346);
+  CHECK_PRINTF ("  12345", "%7w16d", (int16_t) 12345);
+  CHECK_PRINTF ("  12345", "%*w16d", 7, (int16_t) 12345);
+  CHECK_PRINTF ("0x3039", "%#w16x", (uint16_t) 12345);
+  CHECK_PRINTF ("0012345", "%.7w16d", (int16_t) 12345);
+  CHECK_PRINTF ("0012345", "%.*w16d", 7, (int16_t) 12345);
+  CHECK_PRINTF ("   0012345", "%10.7w16d", (int16_t) 12345);
+  CHECK_PRINTF ("   0012345", "%*.7w16d", 10, (int16_t) 12345);
+  CHECK_PRINTF ("   0012345", "%10.*w16d", 7, (int16_t) 12345);
+  CHECK_PRINTF ("   0012345", "%*.*w16d", 10, 7, (int16_t) 12345);
+  CHECK_PRINTF ("0012345   ", "%-10.7w16d", (int16_t) 12345);
+  CHECK_PRINTF ("0012345   ", "%-*.7w16d", 10, (int16_t) 12345);
+  CHECK_PRINTF ("0012345   ", "%-10.*w16d", 7, (int16_t) 12345);
+  CHECK_PRINTF ("0012345   ", "%-*.*w16d", 10, 7, (int16_t) 12345);
+  n = -1;
+  CHECK_PRINTF ("12345", "%d%w16n", 12345, &n);
+  TEST_COMPARE (n, 5);
+  CHECK_PRINTF ("12345", "%w16d", (int_least16_t) 12345);
+  CHECK_PRINTF ("-12345", "%w16d", (int_least16_t) -12345);
+  CHECK_PRINTF ("12345", "%w16i", (int_least16_t) 12345);
+  CHECK_PRINTF ("-12345", "%w16i", (int_least16_t) -12345);
+  CHECK_PRINTF ("11000000111001", "%w16b", (uint_least16_t) 12345);
+  CHECK_PRINTF ("11000000111001", "%w16B", (uint_least16_t) 12345);
+  CHECK_PRINTF ("30071", "%w16o", (uint_least16_t) 12345);
+  CHECK_PRINTF ("12345", "%w16u", (uint_least16_t) 12345);
+  CHECK_PRINTF ("303a", "%w16x", (uint_least16_t) 12346);
+  CHECK_PRINTF ("303A", "%w16X", (uint_least16_t) 12346);
+  CHECK_PRINTF ("  12345", "%7w16d", (int_least16_t) 12345);
+  CHECK_PRINTF ("  12345", "%*w16d", 7, (int_least16_t) 12345);
+  CHECK_PRINTF ("0x3039", "%#w16x", (uint_least16_t) 12345);
+  CHECK_PRINTF ("0012345", "%.7w16d", (int_least16_t) 12345);
+  CHECK_PRINTF ("0012345", "%.*w16d", 7, (int_least16_t) 12345);
+  CHECK_PRINTF ("   0012345", "%10.7w16d", (int_least16_t) 12345);
+  CHECK_PRINTF ("   0012345", "%*.7w16d", 10, (int_least16_t) 12345);
+  CHECK_PRINTF ("   0012345", "%10.*w16d", 7, (int_least16_t) 12345);
+  CHECK_PRINTF ("   0012345", "%*.*w16d", 10, 7, (int_least16_t) 12345);
+  CHECK_PRINTF ("0012345   ", "%-10.7w16d", (int_least16_t) 12345);
+  CHECK_PRINTF ("0012345   ", "%-*.7w16d", 10, (int_least16_t) 12345);
+  CHECK_PRINTF ("0012345   ", "%-10.*w16d", 7, (int_least16_t) 12345);
+  CHECK_PRINTF ("0012345   ", "%-*.*w16d", 10, 7, (int_least16_t) 12345);
+  ln = -1;
+  CHECK_PRINTF ("12345", "%d%w16n", 12345, &ln);
+  TEST_COMPARE (ln, 5);
+  /* Test truncation of value in promoted type not representable in
+     narrower type.  */
+  CHECK_PRINTF ("4464", "%w16d", 70000);
+  CHECK_PRINTF ("-4464", "%w16d", -70000);
+  CHECK_PRINTF ("-7616", "%w16d", 123456);
+  CHECK_PRINTF ("7616", "%w16d", -123456);
+  CHECK_PRINTF ("57920", "%w16u", 123456);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 10 test2 20", "%4$s %3$w16d %2$s %1$w16d",
+		65556, "test2", 65546, "test");
+}
+
+static void
+test_wf16 (void)
+{
+  CHAR buf[1024];
+  int_fast16_t n;
+  _Static_assert (sizeof (int_fast16_t) == sizeof (long int),
+		  "test assumes size of int_fast16_t");
+  CHECK_PRINTF ("1234567", "%wf16d", (int_fast16_t) 1234567);
+  CHECK_PRINTF ("-1234567", "%wf16d", (int_fast16_t) -1234567);
+  CHECK_PRINTF ("1234567", "%wf16i", (int_fast16_t) 1234567);
+  CHECK_PRINTF ("-1234567", "%wf16i", (int_fast16_t) -1234567);
+  CHECK_PRINTF ("100101101011010000111", "%wf16b", (uint_fast16_t) 1234567);
+  CHECK_PRINTF ("100101101011010000111", "%wf16B", (uint_fast16_t) 1234567);
+  CHECK_PRINTF ("4553207", "%wf16o", (uint_fast16_t) 1234567);
+  CHECK_PRINTF ("1234567", "%wf16u", (uint_fast16_t) 1234567);
+  CHECK_PRINTF ("12d687", "%wf16x", (uint_fast16_t) 1234567);
+  CHECK_PRINTF ("12D687", "%wf16X", (uint_fast16_t) 1234567);
+  CHECK_PRINTF ("  1234567", "%9wf16d", (int_fast16_t) 1234567);
+  CHECK_PRINTF ("  1234567", "%*wf16d", 9, (int_fast16_t) 1234567);
+  CHECK_PRINTF ("0x12d687", "%#wf16x", (uint_fast16_t) 1234567);
+  CHECK_PRINTF ("001234567", "%.9wf16d", (int_fast16_t) 1234567);
+  CHECK_PRINTF ("001234567", "%.*wf16d", 9, (int_fast16_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%12.9wf16d", (int_fast16_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%*.9wf16d", 12, (int_fast16_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%12.*wf16d", 9, (int_fast16_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%*.*wf16d", 12, 9, (int_fast16_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-12.9wf16d", (int_fast16_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-*.9wf16d", 12, (int_fast16_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-12.*wf16d", 9, (int_fast16_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-*.*wf16d", 12, 9, (int_fast16_t) 1234567);
+  n = -1;
+  CHECK_PRINTF ("12345", "%d%wf16n", 12345, &n);
+  TEST_COMPARE (n, 5);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 123456 test2 234567", "%4$s %3$wf16d %2$s %1$wf16d",
+		(int_fast16_t) 234567, "test2", (int_fast16_t) 123456, "test");
+#if INT_FAST16_MAX > 0x7fffffff
+  CHECK_PRINTF ("12345678901", "%wf16d", (int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%wf16d", (int_fast16_t) -12345678901LL);
+  CHECK_PRINTF ("12345678901", "%wf16i", (int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%wf16i", (int_fast16_t) -12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%wf16b",
+		(uint_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%wf16B",
+		(uint_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("133767016065", "%wf16o", (uint_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("12345678901", "%wf16u", (uint_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("2dfdc1c35", "%wf16x", (uint_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("2DFDC1C35", "%wf16X", (uint_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%13wf16d", (int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%*wf16d", 13, (int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("0x2dfdc1c35", "%#wf16x", (uint_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.13wf16d", (int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.*wf16d", 13, (int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.13wf16d",
+		(int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.13wf16d", 16,
+		(int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.*wf16d", 13,
+		(int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.*wf16d", 16, 13,
+		(int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.13wf16d",
+		(int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.13wf16d", 16,
+		(int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.*wf16d", 13,
+		(int_fast16_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.*wf16d", 16, 13,
+		(int_fast16_t) 12345678901LL);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 123456789012 test2 234567890123",
+		"%4$s %3$wf16d %2$s %1$wf16d",
+		(int_fast16_t) 234567890123ULL, "test2",
+		(int_fast16_t) 123456789012ULL, "test");
+#endif
+}
+
+static void
+test_w32 (void)
+{
+  CHAR buf[1024];
+  int32_t n;
+  int_least32_t ln;
+  CHECK_PRINTF ("1234567", "%w32d", (int32_t) 1234567);
+  CHECK_PRINTF ("-1234567", "%w32d", (int32_t) -1234567);
+  CHECK_PRINTF ("1234567", "%w32i", (int32_t) 1234567);
+  CHECK_PRINTF ("-1234567", "%w32i", (int32_t) -1234567);
+  CHECK_PRINTF ("100101101011010000111", "%w32b", (uint32_t) 1234567);
+  CHECK_PRINTF ("100101101011010000111", "%w32B", (uint32_t) 1234567);
+  CHECK_PRINTF ("4553207", "%w32o", (uint32_t) 1234567);
+  CHECK_PRINTF ("1234567", "%w32u", (uint32_t) 1234567);
+  CHECK_PRINTF ("12d687", "%w32x", (uint32_t) 1234567);
+  CHECK_PRINTF ("12D687", "%w32X", (uint32_t) 1234567);
+  CHECK_PRINTF ("  1234567", "%9w32d", (int32_t) 1234567);
+  CHECK_PRINTF ("  1234567", "%*w32d", 9, (int32_t) 1234567);
+  CHECK_PRINTF ("0x12d687", "%#w32x", (uint32_t) 1234567);
+  CHECK_PRINTF ("001234567", "%.9w32d", (int32_t) 1234567);
+  CHECK_PRINTF ("001234567", "%.*w32d", 9, (int32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%12.9w32d", (int32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%*.9w32d", 12, (int32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%12.*w32d", 9, (int32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%*.*w32d", 12, 9, (int32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-12.9w32d", (int32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-*.9w32d", 12, (int32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-12.*w32d", 9, (int32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-*.*w32d", 12, 9, (int32_t) 1234567);
+  n = -1;
+  CHECK_PRINTF ("12345", "%d%w32n", 12345, &n);
+  TEST_COMPARE (n, 5);
+  CHECK_PRINTF ("1234567", "%w32d", (int_least32_t) 1234567);
+  CHECK_PRINTF ("-1234567", "%w32d", (int_least32_t) -1234567);
+  CHECK_PRINTF ("1234567", "%w32i", (int_least32_t) 1234567);
+  CHECK_PRINTF ("-1234567", "%w32i", (int_least32_t) -1234567);
+  CHECK_PRINTF ("100101101011010000111", "%w32b", (uint_least32_t) 1234567);
+  CHECK_PRINTF ("100101101011010000111", "%w32B", (uint_least32_t) 1234567);
+  CHECK_PRINTF ("4553207", "%w32o", (uint_least32_t) 1234567);
+  CHECK_PRINTF ("1234567", "%w32u", (uint_least32_t) 1234567);
+  CHECK_PRINTF ("12d687", "%w32x", (uint_least32_t) 1234567);
+  CHECK_PRINTF ("12D687", "%w32X", (uint_least32_t) 1234567);
+  CHECK_PRINTF ("  1234567", "%9w32d", (int_least32_t) 1234567);
+  CHECK_PRINTF ("  1234567", "%*w32d", 9, (int_least32_t) 1234567);
+  CHECK_PRINTF ("0x12d687", "%#w32x", (uint_least32_t) 1234567);
+  CHECK_PRINTF ("001234567", "%.9w32d", (int_least32_t) 1234567);
+  CHECK_PRINTF ("001234567", "%.*w32d", 9, (int_least32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%12.9w32d", (int_least32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%*.9w32d", 12, (int_least32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%12.*w32d", 9, (int_least32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%*.*w32d", 12, 9, (int_least32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-12.9w32d", (int_least32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-*.9w32d", 12, (int_least32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-12.*w32d", 9, (int_least32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-*.*w32d", 12, 9, (int_least32_t) 1234567);
+  ln = -1;
+  CHECK_PRINTF ("12345", "%d%w32n", 12345, &ln);
+  TEST_COMPARE (ln, 5);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 123456 test2 234567", "%4$s %3$w32d %2$s %1$w32d",
+		INT32_C (234567), "test2", INT32_C (123456), "test");
+}
+
+static void
+test_wf32 (void)
+{
+  CHAR buf[1024];
+  int_fast32_t n;
+  _Static_assert (sizeof (int_fast32_t) == sizeof (long int),
+		  "test assumes size of int_fast32_t");
+  CHECK_PRINTF ("1234567", "%wf32d", (int_fast32_t) 1234567);
+  CHECK_PRINTF ("-1234567", "%wf32d", (int_fast32_t) -1234567);
+  CHECK_PRINTF ("1234567", "%wf32i", (int_fast32_t) 1234567);
+  CHECK_PRINTF ("-1234567", "%wf32i", (int_fast32_t) -1234567);
+  CHECK_PRINTF ("100101101011010000111", "%wf32b", (uint_fast32_t) 1234567);
+  CHECK_PRINTF ("100101101011010000111", "%wf32B", (uint_fast32_t) 1234567);
+  CHECK_PRINTF ("4553207", "%wf32o", (uint_fast32_t) 1234567);
+  CHECK_PRINTF ("1234567", "%wf32u", (uint_fast32_t) 1234567);
+  CHECK_PRINTF ("12d687", "%wf32x", (uint_fast32_t) 1234567);
+  CHECK_PRINTF ("12D687", "%wf32X", (uint_fast32_t) 1234567);
+  CHECK_PRINTF ("  1234567", "%9wf32d", (int_fast32_t) 1234567);
+  CHECK_PRINTF ("  1234567", "%*wf32d", 9, (int_fast32_t) 1234567);
+  CHECK_PRINTF ("0x12d687", "%#wf32x", (uint_fast32_t) 1234567);
+  CHECK_PRINTF ("001234567", "%.9wf32d", (int_fast32_t) 1234567);
+  CHECK_PRINTF ("001234567", "%.*wf32d", 9, (int_fast32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%12.9wf32d", (int_fast32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%*.9wf32d", 12, (int_fast32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%12.*wf32d", 9, (int_fast32_t) 1234567);
+  CHECK_PRINTF ("   001234567", "%*.*wf32d", 12, 9, (int_fast32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-12.9wf32d", (int_fast32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-*.9wf32d", 12, (int_fast32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-12.*wf32d", 9, (int_fast32_t) 1234567);
+  CHECK_PRINTF ("001234567   ", "%-*.*wf32d", 12, 9, (int_fast32_t) 1234567);
+  n = -1;
+  CHECK_PRINTF ("12345", "%d%wf32n", 12345, &n);
+  TEST_COMPARE (n, 5);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 123456 test2 234567", "%4$s %3$wf32d %2$s %1$wf32d",
+		(int_fast32_t) 234567, "test2", (int_fast32_t) 123456, "test");
+#if INT_FAST32_MAX > 0x7fffffff
+  CHECK_PRINTF ("12345678901", "%wf32d", (int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%wf32d", (int_fast32_t) -12345678901LL);
+  CHECK_PRINTF ("12345678901", "%wf32i", (int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%wf32i", (int_fast32_t) -12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%wf32b",
+		(uint_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%wf32B",
+		(uint_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("133767016065", "%wf32o", (uint_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("12345678901", "%wf32u", (uint_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("2dfdc1c35", "%wf32x", (uint_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("2DFDC1C35", "%wf32X", (uint_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%13wf32d", (int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%*wf32d", 13, (int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("0x2dfdc1c35", "%#wf32x", (uint_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.13wf32d", (int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.*wf32d", 13, (int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.13wf32d",
+		(int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.13wf32d", 16,
+		(int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.*wf32d", 13,
+		(int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.*wf32d", 16, 13,
+		(int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.13wf32d",
+		(int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.13wf32d", 16,
+		(int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.*wf32d", 13,
+		(int_fast32_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.*wf32d", 16, 13,
+		(int_fast32_t) 12345678901LL);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 123456789012 test2 234567890123",
+		"%4$s %3$wf32d %2$s %1$wf32d",
+		(int_fast32_t) 234567890123ULL, "test2",
+		(int_fast32_t) 123456789012ULL, "test");
+#endif
+}
+
+static void
+test_w64 (void)
+{
+  CHAR buf[1024];
+  int64_t n;
+  int_least64_t ln;
+  CHECK_PRINTF ("12345678901", "%w64d", (int64_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%w64d", (int64_t) -12345678901LL);
+  CHECK_PRINTF ("12345678901", "%w64i", (int64_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%w64i", (int64_t) -12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%w64b",
+		(uint64_t) 12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%w64B",
+		(uint64_t) 12345678901LL);
+  CHECK_PRINTF ("133767016065", "%w64o", (uint64_t) 12345678901LL);
+  CHECK_PRINTF ("12345678901", "%w64u", (uint64_t) 12345678901LL);
+  CHECK_PRINTF ("2dfdc1c35", "%w64x", (uint64_t) 12345678901LL);
+  CHECK_PRINTF ("2DFDC1C35", "%w64X", (uint64_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%13w64d", (int64_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%*w64d", 13, (int64_t) 12345678901LL);
+  CHECK_PRINTF ("0x2dfdc1c35", "%#w64x", (uint64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.13w64d", (int64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.*w64d", 13, (int64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.13w64d", (int64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.13w64d", 16, (int64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.*w64d", 13, (int64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.*w64d", 16, 13,
+		(int64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.13w64d", (int64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.13w64d", 16, (int64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.*w64d", 13, (int64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.*w64d", 16, 13,
+		(int64_t) 12345678901LL);
+  n = -1;
+  CHECK_PRINTF ("12345", "%d%w64n", 12345, &n);
+  TEST_COMPARE (n, 5);
+  CHECK_PRINTF ("12345678901", "%w64d", (int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%w64d", (int_least64_t) -12345678901LL);
+  CHECK_PRINTF ("12345678901", "%w64i", (int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%w64i", (int_least64_t) -12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%w64b",
+		(uint_least64_t) 12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%w64B",
+		(uint_least64_t) 12345678901LL);
+  CHECK_PRINTF ("133767016065", "%w64o", (uint_least64_t) 12345678901LL);
+  CHECK_PRINTF ("12345678901", "%w64u", (uint_least64_t) 12345678901LL);
+  CHECK_PRINTF ("2dfdc1c35", "%w64x", (uint_least64_t) 12345678901LL);
+  CHECK_PRINTF ("2DFDC1C35", "%w64X", (uint_least64_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%13w64d", (int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%*w64d", 13, (int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("0x2dfdc1c35", "%#w64x", (uint_least64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.13w64d", (int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.*w64d", 13, (int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.13w64d",
+		(int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.13w64d", 16,
+		(int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.*w64d", 13,
+		(int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.*w64d", 16, 13,
+		(int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.13w64d",
+		(int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.13w64d", 16,
+		(int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.*w64d", 13,
+		(int_least64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.*w64d", 16, 13,
+		(int_least64_t) 12345678901LL);
+  ln = -1;
+  CHECK_PRINTF ("12345", "%d%w64n", 12345, &ln);
+  TEST_COMPARE (ln, 5);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 123456789012 test2 234567890123",
+		"%4$s %3$w64d %2$s %1$w64d",
+		INT64_C (234567890123), "test2",
+		INT64_C (123456789012), "test");
+}
+
+static void
+test_wf64 (void)
+{
+  CHAR buf[1024];
+  int_fast64_t n;
+  _Static_assert (sizeof (int_fast64_t) == sizeof (long long int),
+		  "test assumes size of int_fast64_t");
+  CHECK_PRINTF ("12345678901", "%wf64d", (int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%wf64d", (int_fast64_t) -12345678901LL);
+  CHECK_PRINTF ("12345678901", "%wf64i", (int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("-12345678901", "%wf64i", (int_fast64_t) -12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%wf64b",
+		(uint_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("1011011111110111000001110000110101", "%wf64B",
+		(uint_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("133767016065", "%wf64o", (uint_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("12345678901", "%wf64u", (uint_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("2dfdc1c35", "%wf64x", (uint_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("2DFDC1C35", "%wf64X", (uint_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%13wf64d", (int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("  12345678901", "%*wf64d", 13, (int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("0x2dfdc1c35", "%#wf64x", (uint_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.13wf64d", (int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901", "%.*wf64d", 13, (int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.13wf64d",
+		(int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.13wf64d", 16,
+		(int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%16.*wf64d", 13,
+		(int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("   0012345678901", "%*.*wf64d", 16, 13,
+		(int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.13wf64d",
+		(int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.13wf64d", 16,
+		(int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-16.*wf64d", 13,
+		(int_fast64_t) 12345678901LL);
+  CHECK_PRINTF ("0012345678901   ", "%-*.*wf64d", 16, 13,
+		(int_fast64_t) 12345678901LL);
+  n = -1;
+  CHECK_PRINTF ("12345", "%d%wf64n", 12345, &n);
+  TEST_COMPARE (n, 5);
+  /* Test positional argument handling.  */
+  CHECK_PRINTF ("test 123456789012 test2 234567890123",
+		"%4$s %3$wf64d %2$s %1$wf64d",
+		(int_fast64_t) 234567890123ULL, "test2",
+		(int_fast64_t) 123456789012ULL, "test");
+}
+
+static int
+do_test (void)
+{
+  test_w8 ();
+  test_wf8 ();
+  test_w16 ();
+  test_wf16 ();
+  test_w32 ();
+  test_wf32 ();
+  test_w64 ();
+  test_wf64 ();
+  /* Bad N in %wN and %wfN are required to produce an error return
+     from printf functions (and can also be seen to be invalid at
+     compile time).  */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (13, "-Wformat");
+  DIAG_IGNORE_NEEDS_COMMENT (13, "-Wformat-extra-args");
+  CHAR buf[1024];
+  CHECK_PRINTF_ERR ("%w1d", 123);
+  CHECK_PRINTF_ERR ("%w123d", 123);
+  CHECK_PRINTF_ERR ("%wf1d", 123);
+  CHECK_PRINTF_ERR ("%wf123d", 123);
+  CHECK_PRINTF_ERR ("%1$w1d", 123);
+  CHECK_PRINTF_ERR ("%1$w123d", 123);
+  CHECK_PRINTF_ERR ("%1$wf1d", 123);
+  CHECK_PRINTF_ERR ("%1$wf123d", 123);
+  DIAG_POP_NEEDS_COMMENT;
+  return 0;
+}
+
+DIAG_POP_NEEDS_COMMENT;
+
+#include <support/test-driver.c>
diff --git a/stdio-common/tst-printf-intn.c b/stdio-common/tst-printf-intn.c
new file mode 100644
index 0000000000..975aebecf7
--- /dev/null
+++ b/stdio-common/tst-printf-intn.c
@@ -0,0 +1,26 @@
+/* Test printf formats for intN_t, int_leastN_t and int_fastN_t types.
+   Narrow string version.
+   Copyright (C) 2023 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
+   <https://www.gnu.org/licenses/>.  */
+
+#define SNPRINTF snprintf
+#define TEST_COMPARE_STRING_MACRO TEST_COMPARE_STRING
+#define STRLEN strlen
+#define CHAR char
+#define L_(C) C
+
+#include <tst-printf-intn-main.c>
diff --git a/stdio-common/vfprintf-internal.c b/stdio-common/vfprintf-internal.c
index c76c06e49b..f30a9e9f3a 100644
--- a/stdio-common/vfprintf-internal.c
+++ b/stdio-common/vfprintf-internal.c
@@ -315,7 +315,7 @@ static const uint8_t jump_table[] =
     /* 'h' */ 10, /* 'i' */ 15, /* 'j' */ 28,            0,
     /* 'l' */ 11, /* 'm' */ 24, /* 'n' */ 23, /* 'o' */ 17,
     /* 'p' */ 22, /* 'q' */ 12,            0, /* 's' */ 21,
-    /* 't' */ 27, /* 'u' */ 16,            0,            0,
+    /* 't' */ 27, /* 'u' */ 16,            0, /* 'w' */ 31,
     /* 'x' */ 18,            0, /* 'z' */ 13
   };
 
@@ -356,7 +356,7 @@ static const uint8_t jump_table[] =
 
 #define STEP0_3_TABLE							      \
     /* Step 0: at the beginning.  */					      \
-    static JUMP_TABLE_TYPE step0_jumps[31] =				      \
+    static JUMP_TABLE_TYPE step0_jumps[32] =				      \
     {									      \
       REF (form_unknown),						      \
       REF (flag_space),		/* for ' ' */				      \
@@ -389,9 +389,10 @@ static const uint8_t jump_table[] =
       REF (mod_intmax_t),       /* for 'j' */				      \
       REF (flag_i18n),		/* for 'I' */				      \
       REF (form_binary),	/* for 'B', 'b' */			      \
+      REF (mod_bitwidth),	/* for 'w' */				      \
     };									      \
     /* Step 1: after processing width.  */				      \
-    static JUMP_TABLE_TYPE step1_jumps[31] =				      \
+    static JUMP_TABLE_TYPE step1_jumps[32] =				      \
     {									      \
       REF (form_unknown),						      \
       REF (form_unknown),	/* for ' ' */				      \
@@ -424,9 +425,10 @@ static const uint8_t jump_table[] =
       REF (mod_intmax_t),       /* for 'j' */				      \
       REF (form_unknown),       /* for 'I' */				      \
       REF (form_binary),	/* for 'B', 'b' */			      \
+      REF (mod_bitwidth),	/* for 'w' */				      \
     };									      \
     /* Step 2: after processing precision.  */				      \
-    static JUMP_TABLE_TYPE step2_jumps[31] =				      \
+    static JUMP_TABLE_TYPE step2_jumps[32] =				      \
     {									      \
       REF (form_unknown),						      \
       REF (form_unknown),	/* for ' ' */				      \
@@ -459,9 +461,10 @@ static const uint8_t jump_table[] =
       REF (mod_intmax_t),       /* for 'j' */				      \
       REF (form_unknown),       /* for 'I' */				      \
       REF (form_binary),	/* for 'B', 'b' */			      \
+      REF (mod_bitwidth),	/* for 'w' */				      \
     };									      \
     /* Step 3a: after processing first 'h' modifier.  */		      \
-    static JUMP_TABLE_TYPE step3a_jumps[31] =				      \
+    static JUMP_TABLE_TYPE step3a_jumps[32] =				      \
     {									      \
       REF (form_unknown),						      \
       REF (form_unknown),	/* for ' ' */				      \
@@ -494,9 +497,10 @@ static const uint8_t jump_table[] =
       REF (form_unknown),       /* for 'j' */				      \
       REF (form_unknown),       /* for 'I' */				      \
       REF (form_binary),	/* for 'B', 'b' */			      \
+      REF (form_unknown),	/* for 'w' */				      \
     };									      \
     /* Step 3b: after processing first 'l' modifier.  */		      \
-    static JUMP_TABLE_TYPE step3b_jumps[31] =				      \
+    static JUMP_TABLE_TYPE step3b_jumps[32] =				      \
     {									      \
       REF (form_unknown),						      \
       REF (form_unknown),	/* for ' ' */				      \
@@ -529,11 +533,12 @@ static const uint8_t jump_table[] =
       REF (form_unknown),       /* for 'j' */				      \
       REF (form_unknown),       /* for 'I' */				      \
       REF (form_binary),	/* for 'B', 'b' */			      \
+      REF (form_unknown),	/* for 'w' */				      \
     }
 
 #define STEP4_TABLE							      \
     /* Step 4: processing format specifier.  */				      \
-    static JUMP_TABLE_TYPE step4_jumps[31] =				      \
+    static JUMP_TABLE_TYPE step4_jumps[32] =				      \
     {									      \
       REF (form_unknown),						      \
       REF (form_unknown),	/* for ' ' */				      \
@@ -566,6 +571,7 @@ static const uint8_t jump_table[] =
       REF (form_unknown),       /* for 'j' */				      \
       REF (form_unknown),       /* for 'I' */				      \
       REF (form_binary),	/* for 'B', 'b' */			      \
+      REF (form_unknown),	/* for 'w' */				      \
     }
 
 /* Handle positional format specifiers.  */
@@ -886,6 +892,56 @@ Xprintf_buffer (struct Xprintf_buffer *buf, const CHAR_T *format,
       is_long = sizeof (intmax_t) > sizeof (unsigned int);
       JUMP (*++f, step4_jumps);
 
+      /* Process 'wN' or 'wfN' modifier.  */
+    LABEL (mod_bitwidth):
+      ++f;
+      bool is_fast = false;
+      if (*f == L_('f'))
+	{
+	  ++f;
+	  is_fast = true;
+	}
+      int bitwidth = 0;
+      if (ISDIGIT (*f))
+	bitwidth = read_int (&f);
+      if (is_fast)
+	switch (bitwidth)
+	  {
+	  case 8:
+	    bitwidth = INT_FAST8_WIDTH;
+	    break;
+	  case 16:
+	    bitwidth = INT_FAST16_WIDTH;
+	    break;
+	  case 32:
+	    bitwidth = INT_FAST32_WIDTH;
+	    break;
+	  case 64:
+	    bitwidth = INT_FAST64_WIDTH;
+	    break;
+	  }
+      switch (bitwidth)
+	{
+	case 8:
+	  is_char = 1;
+	  break;
+	case 16:
+	  is_short = 1;
+	  break;
+	case 32:
+	  break;
+	case 64:
+	  is_long_double = 1;
+	  is_long = 1;
+	  break;
+	default:
+	  /* ISO C requires this error to be detected.  */
+	  __set_errno (EINVAL);
+	  Xprintf_buffer_mark_failed (buf);
+	  goto all_done;
+	}
+      JUMP (*f, step4_jumps);
+
       /* Process current format.  */
       while (1)
 	{
@@ -1053,11 +1109,19 @@ printf_positional (struct Xprintf_buffer * buf, const CHAR_T *format,
 	}
 
       /* Parse the format specifier.  */
+      bool failed;
 #ifdef COMPILE_WPRINTF
-      nargs += __parse_one_specwc (f, nargs, &specs[nspecs], &max_ref_arg);
+      nargs += __parse_one_specwc (f, nargs, &specs[nspecs], &max_ref_arg,
+				   &failed);
 #else
-      nargs += __parse_one_specmb (f, nargs, &specs[nspecs], &max_ref_arg);
+      nargs += __parse_one_specmb (f, nargs, &specs[nspecs], &max_ref_arg,
+				   &failed);
 #endif
+      if (failed)
+	{
+	  Xprintf_buffer_mark_failed (buf);
+	  goto all_done;
+	}
     }
 
   /* Determine the number of arguments the format string consumes.  */
diff --git a/wcsmbs/Makefile b/wcsmbs/Makefile
index ea8ea7b3e6..b03423d1e7 100644
--- a/wcsmbs/Makefile
+++ b/wcsmbs/Makefile
@@ -166,6 +166,7 @@ tests := \
   tst-wcstol-binary-gnu2x \
   tst-wcstol-locale \
   tst-wprintf-binary \
+  tst-wprintf-intn \
   tst-wscanf-binary-c11 \
   tst-wscanf-binary-c2x \
   tst-wscanf-binary-gnu11 \
diff --git a/wcsmbs/tst-wprintf-intn.c b/wcsmbs/tst-wprintf-intn.c
new file mode 100644
index 0000000000..0c0eb80c2c
--- /dev/null
+++ b/wcsmbs/tst-wprintf-intn.c
@@ -0,0 +1,26 @@
+/* Test printf formats for intN_t, int_leastN_t and int_fastN_t types.
+   Wide string version.
+   Copyright (C) 2023 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
+   <https://www.gnu.org/licenses/>.  */
+
+#define SNPRINTF swprintf
+#define TEST_COMPARE_STRING_MACRO TEST_COMPARE_STRING_WIDE
+#define STRLEN wcslen
+#define CHAR wchar_t
+#define L_(C) L ## C
+
+#include "../stdio-common/tst-printf-intn-main.c"
