diff --git a/stdlib/stdbit.h b/stdlib/stdbit.h
new file mode 100644
index 0000000000..1baf27953a
--- /dev/null
+++ b/stdlib/stdbit.h
@@ -0,0 +1,1002 @@
+/* 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/>.  */
+
+/*
+ *      ISO C23: 7.18 Bit and byte utilities <stdbit.h>
+ */
+
+#ifndef _STDBIT_H
+#define _STDBIT_H	1
+
+#define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION
+#include <bits/libc-header-start.h>
+
+__BEGIN_DECLS
+
+#define __need_size_t
+#include <stddef.h>
+#include <bits/stdint-intn.h>
+#include <bits/stdint-uintn.h>
+
+#define __STDC_VERSION_STDBIT_H__ 202311L
+
+#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) \
+    && defined(__ORDER_BIG_ENDIAN__)
+# define __STDC_ENDIAN_LITTLE__ __ORDER_LITTLE_ENDIAN__
+# define __STDC_ENDIAN_BIG__ __ORDER_BIG_ENDIAN__
+# define __STDC_ENDIAN_NATIVE__ __BYTE_ORDER__
+#endif
+
+unsigned int stdc_leading_zeros_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_leading_zeros_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_leading_zeros_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_leading_zeros_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_leading_zeros_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_leading_ones_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_leading_ones_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_leading_ones_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_leading_ones_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_leading_ones_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_trailing_zeros_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_trailing_zeros_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_trailing_zeros_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_trailing_zeros_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_trailing_zeros_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_trailing_ones_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_trailing_ones_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_trailing_ones_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_trailing_ones_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_trailing_ones_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_first_leading_zero_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_leading_zero_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_leading_zero_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_leading_zero_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_leading_zero_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_first_leading_one_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_leading_one_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_leading_one_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_leading_one_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_leading_one_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_first_trailing_zero_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_trailing_zero_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_trailing_zero_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_trailing_zero_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_trailing_zero_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_first_trailing_one_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_trailing_one_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_trailing_one_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_trailing_one_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_first_trailing_one_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_count_zeros_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_count_zeros_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_count_zeros_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_count_zeros_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_count_zeros_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_count_ones_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_count_ones_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_count_ones_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_count_ones_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_count_ones_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+_Bool stdc_has_single_bit_uc (unsigned char __value)
+  __THROW __attribute_const__;
+_Bool stdc_has_single_bit_us (unsigned short __value)
+  __THROW __attribute_const__;
+_Bool stdc_has_single_bit_ui (unsigned int __value)
+  __THROW __attribute_const__;
+_Bool stdc_has_single_bit_ul (unsigned long __value)
+  __THROW __attribute_const__;
+_Bool stdc_has_single_bit_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned int stdc_bit_width_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned int stdc_bit_width_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_bit_width_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned int stdc_bit_width_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned int stdc_bit_width_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned char stdc_bit_floor_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned short stdc_bit_floor_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_bit_floor_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned long stdc_bit_floor_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned long long stdc_bit_floor_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+unsigned char stdc_bit_ceil_uc (unsigned char __value)
+  __THROW __attribute_const__;
+unsigned short stdc_bit_ceil_us (unsigned short __value)
+  __THROW __attribute_const__;
+unsigned int stdc_bit_ceil_ui (unsigned int __value)
+  __THROW __attribute_const__;
+unsigned long stdc_bit_ceil_ul (unsigned long __value)
+  __THROW __attribute_const__;
+unsigned long long stdc_bit_ceil_ull (unsigned long long __value)
+  __THROW __attribute_const__;
+
+#if __GNUC_PREREQ (3, 4) && defined(__extern_always_inline)
+__extern_always_inline unsigned int
+__NTH (stdc_leading_zeros_uc (unsigned char __value))
+{
+  return (__value == 0 ? __builtin_popcount ((unsigned char) ~0U)
+	  : __builtin_clz (__value) - __builtin_popcount (~(unsigned char) ~0U));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_leading_zeros_us (unsigned short __value))
+{
+  return (__value == 0 ? __builtin_popcount ((unsigned short) ~0U)
+	  : __builtin_clz (__value) - __builtin_popcount (~(unsigned short) ~0U));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_leading_zeros_ui (unsigned int __value))
+{
+  return __value == 0 ? __builtin_popcount (~0U) : __builtin_clz (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_leading_zeros_ul (unsigned long __value))
+{
+  return __value == 0 ? __builtin_popcountl (~0UL) : __builtin_clzl (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_leading_zeros_ull (unsigned long long __value))
+{
+  return (__value == 0 ? __builtin_popcountll (~0ULL)
+	  : __builtin_clzll (__value));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_leading_ones_uc (unsigned char __value))
+{
+  return stdc_leading_zeros_uc ((unsigned char) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_leading_ones_us (unsigned short __value))
+{
+  return stdc_leading_zeros_us ((unsigned short) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_leading_ones_ui (unsigned int __value))
+{
+  return stdc_leading_zeros_ui ((unsigned int) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_leading_ones_ul (unsigned long __value))
+{
+  return stdc_leading_zeros_ul ((unsigned long) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_leading_ones_ull (unsigned long long __value))
+{
+  return stdc_leading_zeros_ull ((unsigned long long) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_zeros_uc (unsigned char __value))
+{
+  return (__value == 0 ? __builtin_popcount ((unsigned char) ~0U)
+	  : __builtin_ctz (__value));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_zeros_us (unsigned short __value))
+{
+  return (__value == 0 ? __builtin_popcount ((unsigned short) ~0U)
+	  : __builtin_ctz (__value));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_zeros_ui (unsigned int __value))
+{
+  return __value == 0 ? __builtin_popcount (~0U) : __builtin_ctz (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_zeros_ul (unsigned long __value))
+{
+  return __value == 0 ? __builtin_popcountl (~0UL) : __builtin_ctzl (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_zeros_ull (unsigned long long __value))
+{
+  return (__value == 0 ? __builtin_popcountll (~0ULL)
+	  : __builtin_ctzll (__value));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_ones_uc (unsigned char __value))
+{
+  return stdc_trailing_zeros_uc ((unsigned char) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_ones_us (unsigned short __value))
+{
+  return stdc_trailing_zeros_us ((unsigned short) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_ones_ui (unsigned int __value))
+{
+  return stdc_trailing_zeros_ui ((unsigned int) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_ones_ul (unsigned long __value))
+{
+  return stdc_trailing_zeros_ul ((unsigned long) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_trailing_ones_ull (unsigned long long __value))
+{
+  return stdc_trailing_zeros_ull ((unsigned long long) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_one_uc (unsigned char __value))
+{
+  return __value == 0 ? 0 : stdc_leading_zeros_uc (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_one_us (unsigned short __value))
+{
+  return __value == 0 ? 0 : stdc_leading_zeros_us (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_one_ui (unsigned int __value))
+{
+  return __value == 0 ? 0 : stdc_leading_zeros_ui (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_one_ul (unsigned long __value))
+{
+  return __value == 0 ? 0 : stdc_leading_zeros_ul (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_one_ull (unsigned long long __value))
+{
+  return __value == 0 ? 0 : stdc_leading_zeros_ull (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_zero_uc (unsigned char __value))
+{
+  return (__value == (unsigned char) ~0 ? 0
+	  : stdc_leading_ones_uc (__value) + 1);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_zero_us (unsigned short __value))
+{
+  return (__value == (unsigned short) ~0 ? 0
+	  : stdc_leading_ones_us (__value) + 1);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_zero_ui (unsigned int __value))
+{
+  return __value == ~0U ? 0 : stdc_leading_ones_ui (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_zero_ul (unsigned long __value))
+{
+  return __value == ~0UL ? 0 : stdc_leading_ones_ul (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_leading_zero_ull (unsigned long long __value))
+{
+  return __value == ~0ULL ? 0 : stdc_leading_ones_ull (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_one_uc (unsigned char __value))
+{
+  return __builtin_ffs (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_one_us (unsigned short __value))
+{
+  return __builtin_ffs (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_one_ui (unsigned int __value))
+{
+  return __builtin_ffs (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_one_ul (unsigned long __value))
+{
+  return __builtin_ffsl (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_one_ull (unsigned long long __value))
+{
+  return __builtin_ffsll (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_zero_uc (unsigned char __value))
+{
+  return (__value == (unsigned char) ~0 ? 0
+	  : stdc_trailing_ones_uc (__value) + 1);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_zero_us (unsigned short __value))
+{
+  return (__value == (unsigned short) ~0 ? 0
+	  : stdc_trailing_ones_us (__value) + 1);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_zero_ui (unsigned int __value))
+{
+  return __value == ~0U ? 0 : stdc_trailing_ones_ui (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_zero_ul (unsigned long __value))
+{
+  return __value == ~0UL ? 0 : stdc_trailing_ones_ul (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_first_trailing_zero_ull (unsigned long long __value))
+{
+  return __value == ~0ULL ? 0 : stdc_trailing_ones_ull (__value) + 1;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_ones_uc (unsigned char __value))
+{
+  return __builtin_popcount (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_ones_us (unsigned short __value))
+{
+  return __builtin_popcount (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_ones_ui (unsigned int __value))
+{
+  return __builtin_popcount (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_ones_ul (unsigned long __value))
+{
+  return __builtin_popcountl (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_ones_ull (unsigned long long __value))
+{
+  return __builtin_popcountll (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_zeros_uc (unsigned char __value))
+{
+  return stdc_count_ones_uc ((unsigned char) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_zeros_us (unsigned short __value))
+{
+  return stdc_count_ones_us ((unsigned short) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_zeros_ui (unsigned int __value))
+{
+  return stdc_count_ones_ui ((unsigned int) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_zeros_ul (unsigned long __value))
+{
+  return stdc_count_ones_ul ((unsigned long) ~__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_count_zeros_ull (unsigned long long __value))
+{
+  return stdc_count_ones_ull ((unsigned long long) ~__value);
+}
+
+__extern_always_inline _Bool
+__NTH (stdc_has_single_bit_uc (unsigned char __value))
+{
+  return __value && (__value & (__value - 1)) == 0;
+}
+
+__extern_always_inline _Bool
+__NTH (stdc_has_single_bit_us (unsigned short __value))
+{
+  return __value && (__value & (__value - 1)) == 0;
+}
+
+__extern_always_inline _Bool
+__NTH (stdc_has_single_bit_ui (unsigned int __value))
+{
+  return __value && (__value & (__value - 1)) == 0;
+}
+
+__extern_always_inline _Bool
+__NTH (stdc_has_single_bit_ul (unsigned long __value))
+{
+  return __value && (__value & (__value - 1)) == 0;
+}
+
+__extern_always_inline _Bool
+__NTH (stdc_has_single_bit_ull (unsigned long long __value))
+{
+  return __value && (__value & (__value - 1)) == 0;
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_bit_width_uc (unsigned char __value))
+{
+  return (__builtin_popcount ((unsigned char) ~0U)
+	  - stdc_leading_zeros_uc (__value));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_bit_width_us (unsigned short __value))
+{
+  return (__builtin_popcount ((unsigned short) ~0U)
+	  - stdc_leading_zeros_us (__value));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_bit_width_ui (unsigned int __value))
+{
+  return __builtin_popcount (~0U) - stdc_leading_zeros_ui (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_bit_width_ul (unsigned long __value))
+{
+  return __builtin_popcountl (~0UL) - stdc_leading_zeros_ul (__value);
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_bit_width_ull (unsigned long long __value))
+{
+  return __builtin_popcountll (~0ULL) - stdc_leading_zeros_ull (__value);
+}
+
+__extern_always_inline unsigned char
+__NTH (stdc_bit_floor_uc (unsigned char __value))
+{
+  return (__value == 0 ? 0U
+	  : 1U << (__builtin_popcount (~0U) - 1 - __builtin_clz (__value)));
+}
+
+__extern_always_inline unsigned short
+__NTH (stdc_bit_floor_us (unsigned short __value))
+{
+  return (__value == 0 ? 0U
+	  : 1U << (__builtin_popcount (~0U) - 1 - __builtin_clz (__value)));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_bit_floor_ui (unsigned int __value))
+{
+  return (__value == 0 ? 0U
+	  : 1U << (__builtin_popcount (~0U) - 1 - __builtin_clz (__value)));
+}
+
+__extern_always_inline unsigned long
+__NTH (stdc_bit_floor_ul (unsigned long __value))
+{
+  return (__value == 0 ? 0UL
+	  : 1UL << (__builtin_popcountl (~0UL)
+		    - 1 - __builtin_clzl (__value)));
+}
+
+__extern_always_inline unsigned long long
+__NTH (stdc_bit_floor_ull (unsigned long long __value))
+{
+  return (__value == 0 ? 0ULL
+	  : 1ULL << (__builtin_popcountll (~0ULL)
+		     - 1 - __builtin_clzll (__value)));
+}
+
+__extern_always_inline unsigned char
+__NTH (stdc_bit_ceil_uc (unsigned char __value))
+{
+  return (__value <= 1 ? 1U
+	  : 1U << (__builtin_popcount (~0U) - __builtin_clz (__value - 1)));
+}
+
+__extern_always_inline unsigned short
+__NTH (stdc_bit_ceil_us (unsigned short __value))
+{
+  return (__value <= 1 ? 1U
+	  : 1U << (__builtin_popcount (~0U) - __builtin_clz (__value - 1)));
+}
+
+__extern_always_inline unsigned int
+__NTH (stdc_bit_ceil_ui (unsigned int __value))
+{
+  return (__value <= 1 ? 1U
+	  : 1U << (__builtin_popcount (~0U) - __builtin_clz (__value - 1)));
+}
+
+__extern_always_inline unsigned long
+__NTH (stdc_bit_ceil_ul (unsigned long __value))
+{
+  return (__value <= 1 ? 1UL
+	  : 1UL << (__builtin_popcountl (~0UL)
+		    - __builtin_clzl (__value - 1)));
+}
+
+__extern_always_inline unsigned long long
+__NTH (stdc_bit_ceil_ull (unsigned long long __value))
+{
+  return (__value <= 1 ? 1ULL
+	  : 1ULL << (__builtin_popcountll (~0ULL)
+		     - __builtin_clzll (__value - 1)));
+}
+#endif
+
+#if __glibc_has_builtin (__builtin_clzg) \
+    && __glibc_has_builtin (__builtin_ctzg) \
+    && __glibc_has_builtin (__builtin_popcountg)
+# define __glibc_type_width(value) \
+  __builtin_popcountg ((__typeof (value)) ~(__typeof (value)) 0)
+# define stdc_leading_zeros(value) \
+  ((unsigned int) __builtin_clzg (value, __glibc_type_width (value)))
+# define stdc_leading_ones(value) \
+  ((unsigned int) __builtin_clzg ((__typeof (value)) ~(value), \
+   __glibc_type_width (value)))
+# define stdc_trailing_zeros(value) \
+  ((unsigned int) __builtin_ctzg (value, __glibc_type_width (value)))
+# define stdc_trailing_ones(value) \
+  ((unsigned int) __builtin_ctzg ((__typeof (value)) ~(value), \
+   __glibc_type_width (value)))
+# define stdc_first_leading_zero(value) \
+  ((unsigned int) __builtin_clzg ((__typeof (value)) ~(value), -1) + 1)
+# define stdc_first_leading_one(value) \
+  ((unsigned int) __builtin_clzg (value, -1) + 1)
+# define stdc_first_trailing_zero(value) \
+  ((unsigned int) __builtin_ctzg ((__typeof (value)) ~(value), -1) + 1)
+# define stdc_first_trailing_one(value) \
+  ((unsigned int) __builtin_ctzg (value, -1) + 1)
+# define stdc_count_zeros(value) \
+  ((unsigned int) __builtin_popcountg ((__typeof (value)) ~(value)))
+# define stdc_count_ones(value) \
+  ((unsigned int) __builtin_popcountg (value))
+# define stdc_bit_width(value) \
+  ((unsigned int) (__glibc_type_width (value)				     \
+		   - __builtin_clzg (value, __glibc_type_width (value))))
+# define stdc_has_single_bit(value) \
+  ({ __typeof (value) __stdc_has_single_bit_val = (value);		     \
+     (_Bool) (__stdc_has_single_bit_val 				     \
+	      && (__stdc_has_single_bit_val				     \
+		  & (__stdc_has_single_bit_val - 1)) == 0); })
+# define stdc_bit_floor(value) \
+  ({ __typeof (value) __stdc_bit_floor_val = (value);			     \
+     __stdc_bit_floor_val == 0 ? (__typeof (__stdc_bit_floor_val)) 0	     \
+     : (__typeof (__stdc_bit_floor_val)) 1				     \
+       << (__glibc_type_width (__stdc_bit_floor_val) - 1		     \
+	   - __builtin_clzg (__stdc_bit_floor_val)); })
+# define stdc_bit_ceil(value) \
+  ({ __typeof (value) __stdc_bit_ceil_val = (value);			     \
+     __stdc_bit_ceil_val <= 1 ? (__typeof (__stdc_bit_ceil_val)) 1	     \
+     : (__typeof (__stdc_bit_ceil_val)) 1				     \
+       << (__glibc_type_width (__stdc_bit_ceil_val)			     \
+	   - __builtin_clzg ((__typeof (__stdc_bit_ceil_val))		     \
+			     (__stdc_bit_ceil_val - 1))); })
+#else
+# define stdc_leading_zeros(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_leading_zeros_uc ((unsigned char) value),    \
+	    unsigned short: stdc_leading_zeros_us ((unsigned short) (value)),\
+	    unsigned int: stdc_leading_zeros_ui ((unsigned int) (value)),    \
+	    unsigned long: stdc_leading_zeros_ul ((unsigned long) (value)),  \
+	    unsigned long long:						     \
+	     stdc_leading_zeros_ull ((unsigned long long) (value)),	     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_leading_zeros_uc ((unsigned char) (value))		     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_leading_zeros_us ((unsigned short) (value))	     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_leading_zeros_ui ((unsigned int) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_leading_zeros_ul ((unsigned long) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_leading_zeros_ull ((unsigned long long) (value))	     \
+	      : 0U)
+# define stdc_leading_ones(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_leading_ones_uc ((unsigned char) (value)),   \
+	    unsigned short: stdc_leading_ones_us ((unsigned short) (value)), \
+	    unsigned int: stdc_leading_ones_ui ((unsigned int) (value)),     \
+	    unsigned long: stdc_leading_ones_ul ((unsigned long) (value)),   \
+	    unsigned long long:						     \
+	      stdc_leading_ones_ull ((unsigned long long) (value)),	     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_leading_ones_uc ((unsigned char) (value))		     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_leading_ones_us ((unsigned short) (value))		     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_leading_ones_ui ((unsigned int) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_leading_ones_ul ((unsigned long) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_leading_ones_ull ((unsigned long long) (value))	     \
+	      : 0U)
+# define stdc_trailing_zeros(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_trailing_zeros_uc ((unsigned char) (value)), \
+	    unsigned short:						     \
+	      stdc_trailing_zeros_us ((unsigned short) (value)),	     \
+	    unsigned int: stdc_trailing_zeros_ui ((unsigned int) (value)),   \
+	    unsigned long: stdc_trailing_zeros_ul ((unsigned long) (value)), \
+	    unsigned long long:						     \
+	      stdc_trailing_zeros_ull ((unsigned long long) (value)),	     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_trailing_zeros_uc ((unsigned char) (value))	     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_trailing_zeros_us ((unsigned short) (value))	     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_trailing_zeros_ui ((unsigned int) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_trailing_zeros_ul ((unsigned long) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_trailing_zeros_ull ((unsigned long long) (value))	     \
+	      : 0U)
+# define stdc_trailing_ones(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_trailing_ones_uc ((unsigned char) (value)),  \
+	    unsigned short: stdc_trailing_ones_us ((unsigned short) (value)),\
+	    unsigned int: stdc_trailing_ones_ui ((unsigned int) (value)),    \
+	    unsigned long: stdc_trailing_ones_ul ((unsigned long) (value)),  \
+	    unsigned long long:						     \
+	      stdc_trailing_ones_ull ((unsigned long long) (value)),	     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_trailing_ones_uc ((unsigned char) (value))		     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_trailing_ones_us ((unsigned short) (value))	     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_trailing_ones_ui ((unsigned int) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_trailing_ones_ul ((unsigned long) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_trailing_ones_ull ((unsigned long long) (value))	     \
+	      : 0U)
+# define stdc_first_leading_zero(value) \
+  _Generic ((value),							     \
+	    unsigned char:						     \
+	      stdc_first_leading_zero_uc ((unsigned char) (value)),	     \
+	    unsigned short:						     \
+	      stdc_first_leading_zero_us ((unsigned short) (value)),	     \
+	    unsigned int:						     \
+	      stdc_first_leading_zero_ui ((unsigned int) (value)),	     \
+	    unsigned long:						     \
+	      stdc_first_leading_zero_ul ((unsigned long) (value)),	     \
+	    unsigned long long:						     \
+	      stdc_first_leading_zero_ull ((unsigned long long) (value)),    \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_first_leading_zero_uc ((unsigned char) (value))	     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_first_leading_zero_us ((unsigned short) (value))	     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_first_leading_zero_ui ((unsigned int) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_first_leading_zero_ul ((unsigned long) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_first_leading_zero_ull ((unsigned long long) (value))   \
+	      : 0U)
+# define stdc_first_leading_one(value) \
+  _Generic ((value),							     \
+	    unsigned char:						     \
+	      stdc_first_leading_one_uc ((unsigned char) (value)),	     \
+	    unsigned short:						     \
+	      stdc_first_leading_one_us ((unsigned short) (value)),	     \
+	    unsigned int: stdc_first_leading_one_ui ((unsigned int) (value)),\
+	    unsigned long:						     \
+	      stdc_first_leading_one_ul ((unsigned long) (value)),	     \
+	    unsigned long long:						     \
+	      stdc_first_leading_one_ull ((unsigned long long) (value)),     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_first_leading_one_uc ((unsigned char) (value))	     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_first_leading_one_us ((unsigned short) (value))	     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_first_leading_one_ui ((unsigned int) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_first_leading_one_ul ((unsigned long) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_first_leading_one_ull ((unsigned long long) (value))    \
+	      : 0U)
+# define stdc_first_trailing_zero(value) \
+  _Generic ((value),							     \
+	    unsigned char:						     \
+	      stdc_first_trailing_zero_uc ((unsigned char) (value)),	     \
+	    unsigned short:						     \
+	      stdc_first_trailing_zero_us ((unsigned short) (value)),	     \
+	    unsigned int:						     \
+	      stdc_first_trailing_zero_ui ((unsigned int) (value)),	     \
+	    unsigned long:						     \
+	      stdc_first_trailing_zero_ul ((unsigned long) (value)),	     \
+	    unsigned long long:						     \
+	      stdc_first_trailing_zero_ull ((unsigned long long) (value)),   \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_first_trailing_zero_uc ((unsigned char) (value))	     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_first_trailing_zero_us ((unsigned short) (value))	     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_first_trailing_zero_ui ((unsigned int) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_first_trailing_zero_ul ((unsigned long) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_first_trailing_zero_ull ((unsigned long long) (value))  \
+	      : 0U)
+# define stdc_first_trailing_one(value) \
+  _Generic ((value),							     \
+	    unsigned char:						     \
+	      stdc_first_trailing_one_uc ((unsigned char) (value)),	     \
+	    unsigned short:						     \
+	      stdc_first_trailing_one_us ((unsigned short) (value)),	     \
+	    unsigned int:						     \
+	      stdc_first_trailing_one_ui ((unsigned int) (value)),	     \
+	    unsigned long:						     \
+	      stdc_first_trailing_one_ul ((unsigned long) (value)),	     \
+	    unsigned long long:						     \
+	      stdc_first_trailing_one_ull ((unsigned long long) (value)),    \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_first_trailing_one_uc ((unsigned char) (value))	     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_first_trailing_one_us ((unsigned short) (value))	     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_first_trailing_one_ui ((unsigned int) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_first_trailing_one_ul ((unsigned long) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_first_trailing_one_ull ((unsigned long long) (value))   \
+	      : 0U)
+# define stdc_count_zeros(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_count_zeros_uc ((unsigned char) (value)),    \
+	    unsigned short: stdc_count_zeros_us ((unsigned short) (value)),  \
+	    unsigned int: stdc_count_zeros_ui ((unsigned int) (value)),	     \
+	    unsigned long: stdc_count_zeros_ul ((unsigned long) (value)),    \
+	    unsigned long long:						     \
+	      stdc_count_zeros_ull ((unsigned long long) (value)),	     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_count_zeros_uc ((unsigned char) (value))		     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_count_zeros_us ((unsigned short) (value))		     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_count_zeros_ui ((unsigned int) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_count_zeros_ul ((unsigned long) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_count_zeros_ull ((unsigned long long) (value))	     \
+	      : 0U)
+# define stdc_count_ones(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_count_ones_uc ((unsigned char) (value)),     \
+	    unsigned short: stdc_count_ones_us ((unsigned short) (value)),   \
+	    unsigned int: stdc_count_ones_ui ((unsigned int) (value)),	     \
+	    unsigned long: stdc_count_ones_ul ((unsigned long) (value)),     \
+	    unsigned long long:						     \
+	      stdc_count_ones_ull ((unsigned long long) (value)),	     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_count_ones_uc ((unsigned char) (value))		     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_count_ones_us ((unsigned short) (value))		     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_count_ones_ui ((unsigned int) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_count_ones_ul ((unsigned long) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_count_ones_ull ((unsigned long long) (value))	     \
+	      : 0U)
+# define stdc_has_single_bit(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_has_single_bit_uc ((unsigned char) (value)), \
+	    unsigned short:						     \
+	      stdc_has_single_bit_us ((unsigned short) (value)),	     \
+	    unsigned int: stdc_has_single_bit_ui ((unsigned int) (value)),   \
+	    unsigned long: stdc_has_single_bit_ul ((unsigned long) (value)), \
+	    unsigned long long:						     \
+	      stdc_has_single_bit_ull ((unsigned long long) (value)),	     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_has_single_bit_uc ((unsigned char) (value))	     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_has_single_bit_us ((unsigned short) (value))	     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_has_single_bit_ui ((unsigned int) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_has_single_bit_ul ((unsigned long) (value))	     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_has_single_bit_ull ((unsigned long long) (value))	     \
+	      : (_Bool) 0)
+# define stdc_bit_width(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_bit_width_uc ((unsigned char) (value)),	     \
+	    unsigned short: stdc_bit_width_us ((unsigned short) (value)),    \
+	    unsigned int: stdc_bit_width_ui ((unsigned int) (value)),	     \
+	    unsigned long: stdc_bit_width_ul ((unsigned long) (value)),	     \
+	    unsigned long long:						     \
+	      stdc_bit_width_ull ((unsigned long long) (value)),	     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? stdc_bit_width_uc ((unsigned char) (value))		     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? stdc_bit_width_us ((unsigned short) (value))		     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? stdc_bit_width_ui ((unsigned int) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? stdc_bit_width_ul ((unsigned long) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? stdc_bit_width_ull ((unsigned long long) (value))	     \
+	      : 0U)
+# define stdc_bit_floor(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_bit_floor_uc ((unsigned char) (value)),	     \
+	    unsigned short: stdc_bit_floor_us ((unsigned short) (value)),    \
+	    unsigned int: stdc_bit_floor_ui ((unsigned int) (value)),	     \
+	    unsigned long: stdc_bit_floor_ul ((unsigned long) (value)),	     \
+	    unsigned long long:						     \
+	      stdc_bit_floor_ull ((unsigned long long) (value)),	     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? (__typeof (value))					     \
+		stdc_bit_floor_uc ((unsigned char) (value))		     \
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? (__typeof (value))					     \
+		stdc_bit_floor_us ((unsigned short) (value))		     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? (__typeof (value)) stdc_bit_floor_ui ((unsigned int) (value))\
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? (__typeof (value))					     \
+		stdc_bit_floor_ul ((unsigned long) (value))		     \
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? (__typeof (value))					     \
+		stdc_bit_floor_ull ((unsigned long long) (value))	     \
+	      : 0U)
+# define stdc_bit_ceil(value) \
+  _Generic ((value),							     \
+	    unsigned char: stdc_bit_ceil_uc ((unsigned char) (value)),	     \
+	    unsigned short: stdc_bit_ceil_us ((unsigned short) (value)),     \
+	    unsigned int: stdc_bit_ceil_ui ((unsigned int) (value)),	     \
+	    unsigned long: stdc_bit_ceil_ul ((unsigned long) (value)),	     \
+	    unsigned long long:						     \
+	      stdc_bit_ceil_ull ((unsigned long long) (value)),		     \
+	    default:							     \
+	      sizeof (value) == sizeof (unsigned char)			     \
+	      ? (__typeof (value)) stdc_bit_ceil_uc ((unsigned char) (value))\
+	      : sizeof (value) == sizeof (unsigned short)		     \
+	      ? (__typeof (value))					     \
+		stdc_bit_ceil_us ((unsigned short) (value))		     \
+	      : sizeof (value) == sizeof (unsigned int)			     \
+	      ? (__typeof (value)) stdc_bit_ceil_ui ((unsigned int) (value)) \
+	      : sizeof (value) == sizeof (unsigned long)		     \
+	      ? (__typeof (value)) stdc_bit_ceil_ul ((unsigned long) (value))\
+	      : sizeof (value) == sizeof (unsigned long long)		     \
+	      ? (__typeof (value))					     \
+		stdc_bit_ceil_ull ((unsigned long long) (value))	     \
+	      : 0U)
+#endif
+
+__END_DECLS
+
+#endif /* stdbit.h */
diff --git a/stdlib/tst-stdbit.c b/stdlib/tst-stdbit.c
new file mode 100644
index 0000000000..95930d1b09
--- /dev/null
+++ b/stdlib/tst-stdbit.c
@@ -0,0 +1,488 @@
+/* Test stdbit.h header.
+   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 <stdbit.h>
+#include <stdlib.h>
+#include <limits.h>
+
+int
+main ()
+{
+  if (stdc_leading_zeros_uc (0) != UCHAR_WIDTH
+      || stdc_leading_zeros ((unsigned char) 0) != UCHAR_WIDTH
+      || stdc_leading_zeros_us (0) != USHRT_WIDTH
+      || stdc_leading_zeros ((unsigned short) 0) != USHRT_WIDTH
+      || stdc_leading_zeros_ui (0) != UINT_WIDTH
+      || stdc_leading_zeros (0U) != UINT_WIDTH
+      || stdc_leading_zeros_ul (0) != ULONG_WIDTH
+      || stdc_leading_zeros (0UL) != ULONG_WIDTH
+      || stdc_leading_zeros_ull (0) != ULLONG_WIDTH
+      || stdc_leading_zeros (0ULL) != ULLONG_WIDTH)
+    abort ();
+  if (stdc_leading_zeros_uc ((unsigned char) ~0U) != 0
+      || stdc_leading_zeros ((unsigned char) ~0U) != 0
+      || stdc_leading_zeros_us ((unsigned short) ~0U) != 0
+      || stdc_leading_zeros ((unsigned short) ~0U) != 0
+      || stdc_leading_zeros_ui (~0U) != 0
+      || stdc_leading_zeros (~0U) != 0
+      || stdc_leading_zeros_ul (~0UL) != 0
+      || stdc_leading_zeros (~0UL) != 0
+      || stdc_leading_zeros_ull (~0ULL) != 0
+      || stdc_leading_zeros (~0ULL) != 0)
+    abort ();
+  if (stdc_leading_zeros_uc (1) != UCHAR_WIDTH - 1
+      || stdc_leading_zeros ((unsigned char) 3) != UCHAR_WIDTH - 2
+      || stdc_leading_zeros_us (5) != USHRT_WIDTH - 3
+      || stdc_leading_zeros ((unsigned short) 9) != USHRT_WIDTH - 4
+      || stdc_leading_zeros_ui (16) != UINT_WIDTH - 5
+      || stdc_leading_zeros (34U) != UINT_WIDTH - 6
+      || stdc_leading_zeros_ul (65) != ULONG_WIDTH - 7
+      || stdc_leading_zeros (130UL) != ULONG_WIDTH - 8
+      || stdc_leading_zeros_ull (275) != ULLONG_WIDTH - 9
+      || stdc_leading_zeros (512ULL) != ULLONG_WIDTH - 10)
+    abort ();
+  if (stdc_leading_ones_uc (0) != 0
+      || stdc_leading_ones ((unsigned char) 0) != 0
+      || stdc_leading_ones_us (0) != 0
+      || stdc_leading_ones ((unsigned short) 0) != 0
+      || stdc_leading_ones_ui (0) != 0
+      || stdc_leading_ones (0U) != 0
+      || stdc_leading_ones_ul (0) != 0
+      || stdc_leading_ones (0UL) != 0
+      || stdc_leading_ones_ull (0) != 0
+      || stdc_leading_ones (0ULL) != 0)
+    abort ();
+  if (stdc_leading_ones_uc ((unsigned char) ~0U) != UCHAR_WIDTH
+      || stdc_leading_ones ((unsigned char) ~0U) != UCHAR_WIDTH
+      || stdc_leading_ones_us ((unsigned short) ~0U) != USHRT_WIDTH
+      || stdc_leading_ones ((unsigned short) ~0U) != USHRT_WIDTH
+      || stdc_leading_ones_ui (~0U) != UINT_WIDTH
+      || stdc_leading_ones (~0U) != UINT_WIDTH
+      || stdc_leading_ones_ul (~0UL) != ULONG_WIDTH
+      || stdc_leading_ones (~0UL) != ULONG_WIDTH
+      || stdc_leading_ones_ull (~0ULL) != ULLONG_WIDTH
+      || stdc_leading_ones (~0ULL) != ULLONG_WIDTH)
+    abort ();
+  if (stdc_leading_ones_uc (~1) != UCHAR_WIDTH - 1
+      || stdc_leading_ones ((unsigned char) ~3) != UCHAR_WIDTH - 2
+      || stdc_leading_ones_us (~5) != USHRT_WIDTH - 3
+      || stdc_leading_ones ((unsigned short) ~9) != USHRT_WIDTH - 4
+      || stdc_leading_ones_ui (~16) != UINT_WIDTH - 5
+      || stdc_leading_ones (~34U) != UINT_WIDTH - 6
+      || stdc_leading_ones_ul (~65UL) != ULONG_WIDTH - 7
+      || stdc_leading_ones (~130UL) != ULONG_WIDTH - 8
+      || stdc_leading_ones_ull (~275ULL) != ULLONG_WIDTH - 9
+      || stdc_leading_ones (~512ULL) != ULLONG_WIDTH - 10)
+    abort ();
+  if (stdc_trailing_zeros_uc (0) != UCHAR_WIDTH
+      || stdc_trailing_zeros ((unsigned char) 0) != UCHAR_WIDTH
+      || stdc_trailing_zeros_us (0) != USHRT_WIDTH
+      || stdc_trailing_zeros ((unsigned short) 0) != USHRT_WIDTH
+      || stdc_trailing_zeros_ui (0) != UINT_WIDTH
+      || stdc_trailing_zeros (0U) != UINT_WIDTH
+      || stdc_trailing_zeros_ul (0) != ULONG_WIDTH
+      || stdc_trailing_zeros (0UL) != ULONG_WIDTH
+      || stdc_trailing_zeros_ull (0) != ULLONG_WIDTH
+      || stdc_trailing_zeros (0ULL) != ULLONG_WIDTH)
+    abort ();
+  if (stdc_trailing_zeros_uc ((unsigned char) ~0U) != 0
+      || stdc_trailing_zeros ((unsigned char) ~0U) != 0
+      || stdc_trailing_zeros_us ((unsigned short) ~0U) != 0
+      || stdc_trailing_zeros ((unsigned short) ~0U) != 0
+      || stdc_trailing_zeros_ui (~0U) != 0
+      || stdc_trailing_zeros (~0U) != 0
+      || stdc_trailing_zeros_ul (~0UL) != 0
+      || stdc_trailing_zeros (~0UL) != 0
+      || stdc_trailing_zeros_ull (~0ULL) != 0
+      || stdc_trailing_zeros (~0ULL) != 0)
+    abort ();
+  if (stdc_trailing_zeros_uc (1) != 0
+      || stdc_trailing_zeros ((unsigned char) 2) != 1
+      || stdc_trailing_zeros_us (4) != 2
+      || stdc_trailing_zeros ((unsigned short) 24) != 3
+      || stdc_trailing_zeros_ui (16) != 4
+      || stdc_trailing_zeros (32U) != 5
+      || stdc_trailing_zeros_ul (192) != 6
+      || stdc_trailing_zeros (128UL) != 7
+      || stdc_trailing_zeros_ull (256) != 8
+      || stdc_trailing_zeros (512ULL) != 9)
+    abort ();
+  if (stdc_trailing_ones_uc (0) != 0
+      || stdc_trailing_ones ((unsigned char) 0) != 0
+      || stdc_trailing_ones_us (0) != 0
+      || stdc_trailing_ones ((unsigned short) 0) != 0
+      || stdc_trailing_ones_ui (0) != 0
+      || stdc_trailing_ones (0U) != 0
+      || stdc_trailing_ones_ul (0) != 0
+      || stdc_trailing_ones (0UL) != 0
+      || stdc_trailing_ones_ull (0) != 0
+      || stdc_trailing_ones (0ULL) != 0)
+    abort ();
+  if (stdc_trailing_ones_uc ((unsigned char) ~0U) != UCHAR_WIDTH
+      || stdc_trailing_ones ((unsigned char) ~0U) != UCHAR_WIDTH
+      || stdc_trailing_ones_us ((unsigned short) ~0U) != USHRT_WIDTH
+      || stdc_trailing_ones ((unsigned short) ~0U) != USHRT_WIDTH
+      || stdc_trailing_ones_ui (~0U) != UINT_WIDTH
+      || stdc_trailing_ones (~0U) != UINT_WIDTH
+      || stdc_trailing_ones_ul (~0UL) != ULONG_WIDTH
+      || stdc_trailing_ones (~0UL) != ULONG_WIDTH
+      || stdc_trailing_ones_ull (~0ULL) != ULLONG_WIDTH
+      || stdc_trailing_ones (~0ULL) != ULLONG_WIDTH)
+    abort ();
+  if (stdc_trailing_ones_uc (7) != 3
+      || stdc_trailing_ones ((unsigned char) 5) != 1
+      || stdc_trailing_ones_us (6) != 0
+      || stdc_trailing_ones ((unsigned short) 15) != 4
+      || stdc_trailing_ones_ui (31 | 128) != 5
+      || stdc_trailing_ones (127U) != 7
+      || stdc_trailing_ones_ul (255UL & ~32UL) != 5
+      || stdc_trailing_ones (511UL) != 9
+      || stdc_trailing_ones_ull (255ULL) != 8
+      || stdc_trailing_ones (~0ULL >> 2) != ULLONG_WIDTH - 2)
+    abort ();
+  if (stdc_first_leading_zero_uc (0) != 1
+      || stdc_first_leading_zero ((unsigned char) 0) != 1
+      || stdc_first_leading_zero_us (0) != 1
+      || stdc_first_leading_zero ((unsigned short) 0) != 1
+      || stdc_first_leading_zero_ui (0) != 1
+      || stdc_first_leading_zero (0U) != 1
+      || stdc_first_leading_zero_ul (0) != 1
+      || stdc_first_leading_zero (0UL) != 1
+      || stdc_first_leading_zero_ull (0) != 1
+      || stdc_first_leading_zero (0ULL) != 1)
+    abort ();
+  if (stdc_first_leading_zero_uc ((unsigned char) ~0U) != 0
+      || stdc_first_leading_zero ((unsigned char) ~0U) != 0
+      || stdc_first_leading_zero_us ((unsigned short) ~0U) != 0
+      || stdc_first_leading_zero ((unsigned short) ~0U) != 0
+      || stdc_first_leading_zero_ui (~0U) != 0
+      || stdc_first_leading_zero (~0U) != 0
+      || stdc_first_leading_zero_ul (~0UL) != 0
+      || stdc_first_leading_zero (~0UL) != 0
+      || stdc_first_leading_zero_ull (~0ULL) != 0
+      || stdc_first_leading_zero (~0ULL) != 0)
+    abort ();
+  if (stdc_first_leading_zero_uc ((unsigned char) ~1U) != UCHAR_WIDTH
+      || stdc_first_leading_zero ((unsigned char) ~3U) != UCHAR_WIDTH - 1
+      || stdc_first_leading_zero_us ((unsigned short) ~7U) != USHRT_WIDTH - 2
+      || stdc_first_leading_zero ((unsigned short) ~15U) != USHRT_WIDTH - 3
+      || stdc_first_leading_zero_ui (~31U) != UINT_WIDTH - 4
+      || stdc_first_leading_zero (~63U) != UINT_WIDTH - 5
+      || stdc_first_leading_zero_ul (~127UL) != ULONG_WIDTH - 6
+      || stdc_first_leading_zero (~255UL) != ULONG_WIDTH - 7
+      || stdc_first_leading_zero_ull (~511ULL) != ULLONG_WIDTH - 8
+      || stdc_first_leading_zero (~1023ULL) != ULLONG_WIDTH - 9)
+    abort ();
+  if (stdc_first_leading_one_uc (0) != 0
+      || stdc_first_leading_one ((unsigned char) 0) != 0
+      || stdc_first_leading_one_us (0) != 0
+      || stdc_first_leading_one ((unsigned short) 0) != 0
+      || stdc_first_leading_one_ui (0) != 0
+      || stdc_first_leading_one (0U) != 0
+      || stdc_first_leading_one_ul (0) != 0
+      || stdc_first_leading_one (0UL) != 0
+      || stdc_first_leading_one_ull (0) != 0
+      || stdc_first_leading_one (0ULL) != 0)
+    abort ();
+  if (stdc_first_leading_one_uc ((unsigned char) ~0U) != 1
+      || stdc_first_leading_one ((unsigned char) ~0U) != 1
+      || stdc_first_leading_one_us ((unsigned short) ~0U) != 1
+      || stdc_first_leading_one ((unsigned short) ~0U) != 1
+      || stdc_first_leading_one_ui (~0U) != 1
+      || stdc_first_leading_one (~0U) != 1
+      || stdc_first_leading_one_ul (~0UL) != 1
+      || stdc_first_leading_one (~0UL) != 1
+      || stdc_first_leading_one_ull (~0ULL) != 1
+      || stdc_first_leading_one (~0ULL) != 1)
+    abort ();
+  if (stdc_first_leading_one_uc (1) != UCHAR_WIDTH
+      || stdc_first_leading_one ((unsigned char) 3) != UCHAR_WIDTH - 1
+      || stdc_first_leading_one_us (5) != USHRT_WIDTH - 2
+      || stdc_first_leading_one ((unsigned short) 9) != USHRT_WIDTH - 3
+      || stdc_first_leading_one_ui (16) != UINT_WIDTH - 4
+      || stdc_first_leading_one (34U) != UINT_WIDTH - 5
+      || stdc_first_leading_one_ul (65UL) != ULONG_WIDTH - 6
+      || stdc_first_leading_one (130UL) != ULONG_WIDTH - 7
+      || stdc_first_leading_one_ull (275ULL) != ULLONG_WIDTH - 8
+      || stdc_first_leading_one (512ULL) != ULLONG_WIDTH - 9)
+    abort ();
+  if (stdc_first_trailing_zero_uc (0) != 1
+      || stdc_first_trailing_zero ((unsigned char) 0) != 1
+      || stdc_first_trailing_zero_us (0) != 1
+      || stdc_first_trailing_zero ((unsigned short) 0) != 1
+      || stdc_first_trailing_zero_ui (0) != 1
+      || stdc_first_trailing_zero (0U) != 1
+      || stdc_first_trailing_zero_ul (0) != 1
+      || stdc_first_trailing_zero (0UL) != 1
+      || stdc_first_trailing_zero_ull (0) != 1
+      || stdc_first_trailing_zero (0ULL) != 1)
+    abort ();
+  if (stdc_first_trailing_zero_uc ((unsigned char) ~0U) != 0
+      || stdc_first_trailing_zero ((unsigned char) ~0U) != 0
+      || stdc_first_trailing_zero_us ((unsigned short) ~0U) != 0
+      || stdc_first_trailing_zero ((unsigned short) ~0U) != 0
+      || stdc_first_trailing_zero_ui (~0U) != 0
+      || stdc_first_trailing_zero (~0U) != 0
+      || stdc_first_trailing_zero_ul (~0UL) != 0
+      || stdc_first_trailing_zero (~0UL) != 0
+      || stdc_first_trailing_zero_ull (~0ULL) != 0
+      || stdc_first_trailing_zero (~0ULL) != 0)
+    abort ();
+  if (stdc_first_trailing_zero_uc (1) != 2
+      || stdc_first_trailing_zero ((unsigned char) 2) != 1
+      || stdc_first_trailing_zero_us (7) != 4
+      || stdc_first_trailing_zero ((unsigned short) 15) != 5
+      || stdc_first_trailing_zero_ui (31) != 6
+      || stdc_first_trailing_zero (63U) != 7
+      || stdc_first_trailing_zero_ul (127U | 512U) != 8
+      || stdc_first_trailing_zero (128UL) != 1
+      || stdc_first_trailing_zero_ull (255) != 9
+      || stdc_first_trailing_zero (511ULL) != 10)
+    abort ();
+  if (stdc_first_trailing_one_uc (0) != 0
+      || stdc_first_trailing_one ((unsigned char) 0) != 0
+      || stdc_first_trailing_one_us (0) != 0
+      || stdc_first_trailing_one ((unsigned short) 0) != 0
+      || stdc_first_trailing_one_ui (0) != 0
+      || stdc_first_trailing_one (0U) != 0
+      || stdc_first_trailing_one_ul (0) != 0
+      || stdc_first_trailing_one (0UL) != 0
+      || stdc_first_trailing_one_ull (0) != 0
+      || stdc_first_trailing_one (0ULL) != 0)
+    abort ();
+  if (stdc_first_trailing_one_uc ((unsigned char) ~0U) != 1
+      || stdc_first_trailing_one ((unsigned char) ~0U) != 1
+      || stdc_first_trailing_one_us ((unsigned short) ~0U) != 1
+      || stdc_first_trailing_one ((unsigned short) ~0U) != 1
+      || stdc_first_trailing_one_ui (~0U) != 1
+      || stdc_first_trailing_one (~0U) != 1
+      || stdc_first_trailing_one_ul (~0UL) != 1
+      || stdc_first_trailing_one (~0UL) != 1
+      || stdc_first_trailing_one_ull (~0ULL) != 1
+      || stdc_first_trailing_one (~0ULL) != 1)
+    abort ();
+  if (stdc_first_trailing_one_uc (7) != 1
+      || stdc_first_trailing_one ((unsigned char) 4) != 3
+      || stdc_first_trailing_one_us (6) != 2
+      || stdc_first_trailing_one ((unsigned short) 96) != 6
+      || stdc_first_trailing_one_ui (128) != 8
+      || stdc_first_trailing_one (127U) != 1
+      || stdc_first_trailing_one_ul (255UL & ~31UL) != 6
+      || stdc_first_trailing_one (511UL) != 1
+      || stdc_first_trailing_one_ull (255ULL << 3) != 4
+      || stdc_first_trailing_one (~0ULL << 12) != 13)
+    abort ();
+  if (stdc_count_zeros_uc (0) != UCHAR_WIDTH
+      || stdc_count_zeros ((unsigned char) 0) != UCHAR_WIDTH
+      || stdc_count_zeros_us (0) != USHRT_WIDTH
+      || stdc_count_zeros ((unsigned short) 0) != USHRT_WIDTH
+      || stdc_count_zeros_ui (0) != UINT_WIDTH
+      || stdc_count_zeros (0U) != UINT_WIDTH
+      || stdc_count_zeros_ul (0) != ULONG_WIDTH
+      || stdc_count_zeros (0UL) != ULONG_WIDTH
+      || stdc_count_zeros_ull (0) != ULLONG_WIDTH
+      || stdc_count_zeros (0ULL) != ULLONG_WIDTH)
+    abort ();
+  if (stdc_count_zeros_uc ((unsigned char) ~0U) != 0
+      || stdc_count_zeros ((unsigned char) ~0U) != 0
+      || stdc_count_zeros_us ((unsigned short) ~0U) != 0
+      || stdc_count_zeros ((unsigned short) ~0U) != 0
+      || stdc_count_zeros_ui (~0U) != 0
+      || stdc_count_zeros (~0U) != 0
+      || stdc_count_zeros_ul (~0UL) != 0
+      || stdc_count_zeros (~0UL) != 0
+      || stdc_count_zeros_ull (~0ULL) != 0
+      || stdc_count_zeros (~0ULL) != 0)
+    abort ();
+  if (stdc_count_zeros_uc ((unsigned char) ~1U) != 1
+      || stdc_count_zeros ((unsigned char) 1U) != UCHAR_WIDTH - 1
+      || stdc_count_zeros_us ((unsigned short) 5U) != USHRT_WIDTH - 2
+      || stdc_count_zeros ((unsigned short) 42) != USHRT_WIDTH - 3
+      || stdc_count_zeros_ui (~42U) != 3
+      || stdc_count_zeros (291U) != UINT_WIDTH - 4
+      || stdc_count_zeros_ul (~291UL) != 4
+      || stdc_count_zeros (~1315UL) != 5
+      || stdc_count_zeros_ull (1315ULL) != ULLONG_WIDTH - 5
+      || stdc_count_zeros (3363ULL) != ULLONG_WIDTH - 6)
+    abort ();
+  if (stdc_count_ones_uc (0) != 0
+      || stdc_count_ones ((unsigned char) 0) != 0
+      || stdc_count_ones_us (0) != 0
+      || stdc_count_ones ((unsigned short) 0) != 0
+      || stdc_count_ones_ui (0) != 0
+      || stdc_count_ones (0U) != 0
+      || stdc_count_ones_ul (0) != 0
+      || stdc_count_ones (0UL) != 0
+      || stdc_count_ones_ull (0) != 0
+      || stdc_count_ones (0ULL) != 0)
+    abort ();
+  if (stdc_count_ones_uc ((unsigned char) ~0U) != UCHAR_WIDTH
+      || stdc_count_ones ((unsigned char) ~0U) != UCHAR_WIDTH
+      || stdc_count_ones_us ((unsigned short) ~0U) != USHRT_WIDTH
+      || stdc_count_ones ((unsigned short) ~0U) != USHRT_WIDTH
+      || stdc_count_ones_ui (~0U) != UINT_WIDTH
+      || stdc_count_ones (~0U) != UINT_WIDTH
+      || stdc_count_ones_ul (~0UL) != ULONG_WIDTH
+      || stdc_count_ones (~0UL) != ULONG_WIDTH
+      || stdc_count_ones_ull (~0ULL) != ULLONG_WIDTH
+      || stdc_count_ones (~0ULL) != ULLONG_WIDTH)
+    abort ();
+  if (stdc_count_ones_uc ((unsigned char) 1U) != 1
+      || stdc_count_ones ((unsigned char) ~1U) != UCHAR_WIDTH - 1
+      || stdc_count_ones_us ((unsigned short) ~5U) != USHRT_WIDTH - 2
+      || stdc_count_ones ((unsigned short) ~42) != USHRT_WIDTH - 3
+      || stdc_count_ones_ui (42U) != 3
+      || stdc_count_ones (~291U) != UINT_WIDTH - 4
+      || stdc_count_ones_ul (291UL) != 4
+      || stdc_count_ones (1315UL) != 5
+      || stdc_count_ones_ull (~1315ULL) != ULLONG_WIDTH - 5
+      || stdc_count_ones (~3363ULL) != ULLONG_WIDTH - 6)
+    abort ();
+  if (stdc_has_single_bit_uc (0)
+      || stdc_has_single_bit ((unsigned char) 0)
+      || stdc_has_single_bit_us (0)
+      || stdc_has_single_bit ((unsigned short) 0)
+      || stdc_has_single_bit_ui (0)
+      || stdc_has_single_bit (0U)
+      || stdc_has_single_bit_ul (0)
+      || stdc_has_single_bit (0UL)
+      || stdc_has_single_bit_ull (0)
+      || stdc_has_single_bit (0ULL))
+    abort ();
+  if (!stdc_has_single_bit_uc (1)
+      || !stdc_has_single_bit ((unsigned char) 2)
+      || !stdc_has_single_bit_us (4)
+      || !stdc_has_single_bit ((unsigned short) 8)
+      || !stdc_has_single_bit_ui (16)
+      || !stdc_has_single_bit (32U)
+      || !stdc_has_single_bit_ul (64)
+      || !stdc_has_single_bit (128UL)
+      || !stdc_has_single_bit_ull (256)
+      || !stdc_has_single_bit (512ULL))
+    abort ();
+  if (stdc_has_single_bit_uc (3)
+      || stdc_has_single_bit ((unsigned char) 7)
+      || stdc_has_single_bit_us (31)
+      || stdc_has_single_bit ((unsigned short) 96)
+      || stdc_has_single_bit_ui (129)
+      || stdc_has_single_bit (513U)
+      || stdc_has_single_bit_ul (511)
+      || stdc_has_single_bit (1022UL)
+      || stdc_has_single_bit_ull (6)
+      || stdc_has_single_bit (12ULL))
+    abort ();
+  if (stdc_bit_width_uc (0) != 0
+      || stdc_bit_width ((unsigned char) 0) != 0
+      || stdc_bit_width_us (0) != 0
+      || stdc_bit_width ((unsigned short) 0) != 0
+      || stdc_bit_width_ui (0) != 0
+      || stdc_bit_width (0U) != 0
+      || stdc_bit_width_ul (0) != 0
+      || stdc_bit_width (0UL) != 0
+      || stdc_bit_width_ull (0) != 0
+      || stdc_bit_width (0ULL) != 0)
+    abort ();
+  if (stdc_bit_width_uc ((unsigned char) ~0U) != UCHAR_WIDTH
+      || stdc_bit_width ((unsigned char) ~0U) != UCHAR_WIDTH
+      || stdc_bit_width_us ((unsigned short) ~0U) != USHRT_WIDTH
+      || stdc_bit_width ((unsigned short) ~0U) != USHRT_WIDTH
+      || stdc_bit_width_ui (~0U) != UINT_WIDTH
+      || stdc_bit_width (~0U) != UINT_WIDTH
+      || stdc_bit_width_ul (~0UL) != ULONG_WIDTH
+      || stdc_bit_width (~0UL) != ULONG_WIDTH
+      || stdc_bit_width_ull (~0ULL) != ULLONG_WIDTH
+      || stdc_bit_width (~0ULL) != ULLONG_WIDTH)
+    abort ();
+  if (stdc_bit_width_uc ((unsigned char) ~0U >> 1) != UCHAR_WIDTH - 1
+      || stdc_bit_width ((unsigned char) 6) != 3
+      || stdc_bit_width_us ((unsigned short) 12U) != 4
+      || stdc_bit_width ((unsigned short) ((unsigned short) ~0U >> 5)) != USHRT_WIDTH - 5
+      || stdc_bit_width_ui (137U) != 8
+      || stdc_bit_width (269U) != 9
+      || stdc_bit_width_ul (39UL) != 6
+      || stdc_bit_width (~0UL >> 2) != ULONG_WIDTH - 2
+      || stdc_bit_width_ull (1023) != 10
+      || stdc_bit_width (1024ULL) != 11)
+    abort ();
+  if (stdc_bit_floor_uc (0) != 0
+      || stdc_bit_floor ((unsigned char) 0) != 0
+      || stdc_bit_floor_us (0) != 0
+      || stdc_bit_floor ((unsigned short) 0) != 0
+      || stdc_bit_floor_ui (0) != 0U
+      || stdc_bit_floor (0U) != 0U
+      || stdc_bit_floor_ul (0) != 0UL
+      || stdc_bit_floor (0UL) != 0UL
+      || stdc_bit_floor_ull (0) != 0ULL
+      || stdc_bit_floor (0ULL) != 0ULL)
+    abort ();
+  if (stdc_bit_floor_uc ((unsigned char) ~0U) != (1U << (UCHAR_WIDTH - 1))
+      || stdc_bit_floor ((unsigned char) ~0U) != (1U << (UCHAR_WIDTH - 1))
+      || stdc_bit_floor_us ((unsigned short) ~0U) != (1U << (USHRT_WIDTH - 1))
+      || stdc_bit_floor ((unsigned short) ~0U) != (1U << (USHRT_WIDTH - 1))
+      || stdc_bit_floor_ui (~0U) != (1U << (UINT_WIDTH - 1))
+      || stdc_bit_floor (~0U) != (1U << (UINT_WIDTH - 1))
+      || stdc_bit_floor_ul (~0UL) != (1UL << (ULONG_WIDTH - 1))
+      || stdc_bit_floor (~0UL) != (1UL << (ULONG_WIDTH - 1))
+      || stdc_bit_floor_ull (~0ULL) != (1ULL << (ULLONG_WIDTH - 1))
+      || stdc_bit_floor (~0ULL) != (1ULL << (ULLONG_WIDTH - 1)))
+    abort ();
+  if (stdc_bit_floor_uc ((unsigned char) 4) != 4
+      || stdc_bit_floor ((unsigned char) 7) != 4
+      || stdc_bit_floor_us ((unsigned short) 8U) != 8
+      || stdc_bit_floor ((unsigned short) 31U) != 16
+      || stdc_bit_floor_ui (137U) != 128U
+      || stdc_bit_floor (269U) != 256U
+      || stdc_bit_floor_ul (511UL) != 256UL
+      || stdc_bit_floor (512UL) != 512UL
+      || stdc_bit_floor_ull (513) != 512ULL
+      || stdc_bit_floor (1024ULL) != 1024ULL)
+    abort ();
+  if (stdc_bit_ceil_uc (0) != 1
+      || stdc_bit_ceil ((unsigned char) 0) != 1
+      || stdc_bit_ceil_us (0) != 1
+      || stdc_bit_ceil ((unsigned short) 0) != 1
+      || stdc_bit_ceil_ui (0) != 1U
+      || stdc_bit_ceil (0U) != 1U
+      || stdc_bit_ceil_ul (0) != 1UL
+      || stdc_bit_ceil (0UL) != 1UL
+      || stdc_bit_ceil_ull (0) != 1ULL
+      || stdc_bit_ceil (0ULL) != 1ULL)
+    abort ();
+  if (stdc_bit_ceil_uc ((unsigned char) ~0U >> 1) != (1U << (UCHAR_WIDTH - 1))
+      || stdc_bit_ceil ((unsigned char) ((unsigned char) ~0U >> 1)) != (1U << (UCHAR_WIDTH - 1))
+      || stdc_bit_ceil_us ((unsigned short) ~0U >> 1) != (1U << (USHRT_WIDTH - 1))
+      || stdc_bit_ceil ((unsigned short) ((unsigned short) ~0U >> 1)) != (1U << (USHRT_WIDTH - 1))
+      || stdc_bit_ceil_ui (~0U >> 1) != (1U << (UINT_WIDTH - 1))
+      || stdc_bit_ceil (1U << (UINT_WIDTH - 1)) != (1U << (UINT_WIDTH - 1))
+      || stdc_bit_ceil_ul (~0UL >> 1) != (1UL << (ULONG_WIDTH - 1))
+      || stdc_bit_ceil (~0UL >> 1) != (1UL << (ULONG_WIDTH - 1))
+      || stdc_bit_ceil_ull (1ULL << (ULLONG_WIDTH - 1)) != (1ULL << (ULLONG_WIDTH - 1))
+      || stdc_bit_ceil (~0ULL >> 1) != (1ULL << (ULLONG_WIDTH - 1)))
+    abort ();
+  if (stdc_bit_ceil_uc ((unsigned char) 1) != 1
+      || stdc_bit_ceil ((unsigned char) 2) != 2
+      || stdc_bit_ceil_us ((unsigned short) 3U) != 4
+      || stdc_bit_ceil ((unsigned short) 4U) != 4
+      || stdc_bit_ceil_ui (5U) != 8U
+      || stdc_bit_ceil (269U) != 512U
+      || stdc_bit_ceil_ul (511UL) != 512UL
+      || stdc_bit_ceil (512UL) != 512UL
+      || stdc_bit_ceil_ull (513) != 1024ULL
+      || stdc_bit_ceil (1025ULL) != 2048ULL)
+    abort ();
+}
