1 files changed, 124 insertions, 0 deletions

diff --git a/include/stdbit.h b/include/stdbit.h
new file mode 100644
index 000000000000..a529676bed4b
--- /dev/null
+++ b/include/stdbit.h
@@ -0,0 +1,124 @@
+/*-
+ * Copyright (c) 2025 Robert Clausecker <fuz@FreeBSD.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#ifndef __STDC_VERSION_STDBIT_H__
+#define __STDC_VERSION_STDBIT_H__ 202311L
+
+#include <sys/cdefs.h>
+
+/* byte order */
+#define  __STDC_ENDIAN_LITTLE__ __ORDER_LITTLE_ENDIAN__
+#define  __STDC_ENDIAN_BIG__ __ORDER_BIG_ENDIAN__
+#define  __STDC_ENDIAN_NATIVE__ __BYTE_ORDER__
+
+#define __generic_bitfunc(func, x) (_Generic(x,				\
+	unsigned char: func ## _uc,					\
+	unsigned short: func ## _us,					\
+	unsigned int: func ## _ui,					\
+	unsigned long: func ## _ul,					\
+	unsigned long long: func ## _ull)(x))
+
+__BEGIN_DECLS
+unsigned int stdc_leading_zeros_uc(unsigned char) __pure2;
+unsigned int stdc_leading_zeros_us(unsigned short) __pure2;
+unsigned int stdc_leading_zeros_ui(unsigned int) __pure2;
+unsigned int stdc_leading_zeros_ul(unsigned long) __pure2;
+unsigned int stdc_leading_zeros_ull(unsigned long long) __pure2;
+#define stdc_leading_zeros(x) __generic_bitfunc(stdc_leading_zeros, x)
+
+unsigned int stdc_leading_ones_uc(unsigned char) __pure2;
+unsigned int stdc_leading_ones_us(unsigned short) __pure2;
+unsigned int stdc_leading_ones_ui(unsigned int) __pure2;
+unsigned int stdc_leading_ones_ul(unsigned long) __pure2;
+unsigned int stdc_leading_ones_ull(unsigned long long) __pure2;
+#define stdc_leading_ones(x) __generic_bitfunc(stdc_leading_ones, x)
+
+unsigned int stdc_trailing_zeros_uc(unsigned char) __pure2;
+unsigned int stdc_trailing_zeros_us(unsigned short) __pure2;
+unsigned int stdc_trailing_zeros_ui(unsigned int) __pure2;
+unsigned int stdc_trailing_zeros_ul(unsigned long) __pure2;
+unsigned int stdc_trailing_zeros_ull(unsigned long long) __pure2;
+#define stdc_trailing_zeros(x) __generic_bitfunc(stdc_trailing_zeros, x)
+
+unsigned int stdc_trailing_ones_uc(unsigned char) __pure2;
+unsigned int stdc_trailing_ones_us(unsigned short) __pure2;
+unsigned int stdc_trailing_ones_ui(unsigned int) __pure2;
+unsigned int stdc_trailing_ones_ul(unsigned long) __pure2;
+unsigned int stdc_trailing_ones_ull(unsigned long long) __pure2;
+#define stdc_trailing_ones(x) __generic_bitfunc(stdc_trailing_ones, x)
+
+unsigned int stdc_first_leading_zero_uc(unsigned char) __pure2;
+unsigned int stdc_first_leading_zero_us(unsigned short) __pure2;
+unsigned int stdc_first_leading_zero_ui(unsigned int) __pure2;
+unsigned int stdc_first_leading_zero_ul(unsigned long) __pure2;
+unsigned int stdc_first_leading_zero_ull(unsigned long long) __pure2;
+#define stdc_first_leading_zero(x) __generic_bitfunc(stdc_first_leading_zero, x)
+
+unsigned int stdc_first_leading_one_uc(unsigned char) __pure2;
+unsigned int stdc_first_leading_one_us(unsigned short) __pure2;
+unsigned int stdc_first_leading_one_ui(unsigned int) __pure2;
+unsigned int stdc_first_leading_one_ul(unsigned long) __pure2;
+unsigned int stdc_first_leading_one_ull(unsigned long long) __pure2;
+#define stdc_first_leading_one(x) __generic_bitfunc(stdc_first_leading_one, x)
+
+unsigned int stdc_first_trailing_zero_uc(unsigned char) __pure2;
+unsigned int stdc_first_trailing_zero_us(unsigned short) __pure2;
+unsigned int stdc_first_trailing_zero_ui(unsigned int) __pure2;
+unsigned int stdc_first_trailing_zero_ul(unsigned long) __pure2;
+unsigned int stdc_first_trailing_zero_ull(unsigned long long) __pure2;
+#define stdc_first_trailing_zero(x) __generic_bitfunc(stdc_first_trailing_zero, x)
+
+unsigned int stdc_first_trailing_one_uc(unsigned char) __pure2;
+unsigned int stdc_first_trailing_one_us(unsigned short) __pure2;
+unsigned int stdc_first_trailing_one_ui(unsigned int) __pure2;
+unsigned int stdc_first_trailing_one_ul(unsigned long) __pure2;
+unsigned int stdc_first_trailing_one_ull(unsigned long long) __pure2;
+#define stdc_first_trailing_one(x) __generic_bitfunc(stdc_first_trailing_one, x)
+
+unsigned int stdc_count_zeros_uc(unsigned char) __pure2;
+unsigned int stdc_count_zeros_us(unsigned short) __pure2;
+unsigned int stdc_count_zeros_ui(unsigned int) __pure2;
+unsigned int stdc_count_zeros_ul(unsigned long) __pure2;
+unsigned int stdc_count_zeros_ull(unsigned long long) __pure2;
+#define stdc_count_zeros(x) __generic_bitfunc(stdc_count_zeros, x)
+
+unsigned int stdc_count_ones_uc(unsigned char) __pure2;
+unsigned int stdc_count_ones_us(unsigned short) __pure2;
+unsigned int stdc_count_ones_ui(unsigned int) __pure2;
+unsigned int stdc_count_ones_ul(unsigned long) __pure2;
+unsigned int stdc_count_ones_ull(unsigned long long) __pure2;
+#define stdc_count_ones(x) __generic_bitfunc(stdc_count_ones, x)
+
+_Bool stdc_has_single_bit_uc(unsigned char) __pure2;
+_Bool stdc_has_single_bit_us(unsigned short) __pure2;
+_Bool stdc_has_single_bit_ui(unsigned int) __pure2;
+_Bool stdc_has_single_bit_ul(unsigned long) __pure2;
+_Bool stdc_has_single_bit_ull(unsigned long long) __pure2;
+#define stdc_has_single_bit(x) __generic_bitfunc(stdc_has_single_bit, x)
+
+unsigned int stdc_bit_width_uc(unsigned char) __pure2;
+unsigned int stdc_bit_width_us(unsigned short) __pure2;
+unsigned int stdc_bit_width_ui(unsigned int) __pure2;
+unsigned int stdc_bit_width_ul(unsigned long) __pure2;
+unsigned int stdc_bit_width_ull(unsigned long long) __pure2;
+#define stdc_bit_width(x) __generic_bitfunc(stdc_bit_width, x)
+
+unsigned char stdc_bit_floor_uc(unsigned char) __pure2;
+unsigned short stdc_bit_floor_us(unsigned short) __pure2;
+unsigned stdc_bit_floor_ui(unsigned int) __pure2;
+unsigned long stdc_bit_floor_ul(unsigned long) __pure2;
+unsigned long long stdc_bit_floor_ull(unsigned long long) __pure2;
+#define stdc_bit_floor(x) __generic_bitfunc(stdc_bit_floor, x)
+
+unsigned char stdc_bit_ceil_uc(unsigned char) __pure2;
+unsigned short stdc_bit_ceil_us(unsigned short) __pure2;
+unsigned int stdc_bit_ceil_ui(unsigned int) __pure2;
+unsigned long stdc_bit_ceil_ul(unsigned long) __pure2;
+unsigned long long stdc_bit_ceil_ull(unsigned long long) __pure2;
+#define stdc_bit_ceil(x) __generic_bitfunc(stdc_bit_ceil, x)
+__END_DECLS
+
+#endif /* __STDC_VERSION_STDBIT_H__ */