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/*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*/
/*
* Copyright 2024 Oxide Computer Company
*/
#ifndef _SYS_STDBIT_H
#define _SYS_STDBIT_H
/*
* This header implements all of the different aspects of the C23 stdbit.h
* functionality. We attempt to make this header useful to all C versions other
* than the type generic interfaces, for which we require the asked for version
* of C to be at least C23. The functions that are present here are allowed to
* be inline or not. To provide wider ranging compiler support we declare extern
* versions of all of these symbols which are provided in both libc and the
* kernel. This also avoids cases where a compiler builtin relies on external
* runtime library support.
*
* In the future, we should provide inline versions with compilers that support
* common builtins.
*/
#include <sys/feature_tests.h>
#include <sys/isa_defs.h>
/*
* This header is required specifically to make the size_t, uintXX_t, and the
* _least_ variants available. The generic values are allowed to leverage the
* 'bool' type. In C23, bool became a keyword as opposed to a definition to
* _Bool. We therefore include it so we can attempt to be consistent and
* generally useful.
*/
#include <sys/int_types.h>
#include <sys/stdbool.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* Declare our version.
*/
#define __STDC_VERSION_STDBIT_H__ 202311L
#if !defined(_SIZE_T) || __cplusplus >= 199711L
#define _SIZE_T
#if defined(_LP64)
typedef unsigned long size_t; /* size of something in bytes */
#else
typedef unsigned int size_t; /* (historical version) */
#endif
#endif /* _SIZE_T */
/*
* Endian values and detection.
*/
#define __STDC_ENDIAN_LITTLE__ 1234
#define __STDC_ENDIAN_BIG__ 4321
#if defined(_LITTLE_ENDIAN)
#define __STDC_ENDIAN_NATIVE__ __STDC_ENDIAN_LITTLE__
#elif defined(_BIG_ENDIAN)
#define __STDC_ENDIAN_NATIVE__ __STDC_ENDIAN_BIG__
#else
#error "Unknown byte order"
#endif /* _LITTLE_ENDIAN */
/*
* Count Leading Zeros
*/
extern unsigned int stdc_leading_zeros_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_leading_zeros_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_leading_zeros_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_leading_zeros_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* Count Leading Ones
*/
extern unsigned int stdc_leading_ones_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_leading_ones_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_leading_ones_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_leading_ones_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* Count Trailing Zeros
*/
extern unsigned int stdc_trailing_zeros_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_trailing_zeros_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_trailing_zeros_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_trailing_zeros_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* Count Trailing Ones
*/
extern unsigned int stdc_trailing_ones_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_trailing_ones_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_trailing_ones_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_trailing_ones_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* First Leading Zero
*/
extern unsigned int stdc_first_leading_zero_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_leading_zero_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_leading_zero_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_leading_zero_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* First Leading One
*/
extern unsigned int stdc_first_leading_one_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_leading_one_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_leading_one_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_leading_one_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* First Trailing Zero
*/
extern unsigned int stdc_first_trailing_zero_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_trailing_zero_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_trailing_zero_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_trailing_zero_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* First Trailing One
*/
extern unsigned int stdc_first_trailing_one_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_trailing_one_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_trailing_one_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_trailing_one_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* Count Zeros
*/
extern unsigned int stdc_count_zeros_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_count_zeros_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_count_zeros_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_count_zeros_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* Count Ones
*/
extern unsigned int stdc_count_ones_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_count_ones_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_count_ones_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_count_ones_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* Single-bit Check
*/
extern bool stdc_has_single_bit_uc(unsigned char) _C23_UNSEQ_ATTR;
extern bool stdc_has_single_bit_us(unsigned short) _C23_UNSEQ_ATTR;
extern bool stdc_has_single_bit_ui(unsigned int) _C23_UNSEQ_ATTR;
extern bool stdc_has_single_bit_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* Bit Width
*/
extern unsigned int stdc_bit_width_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned int stdc_bit_width_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_bit_width_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned int stdc_bit_width_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* Bit Floor
*/
extern unsigned char stdc_bit_floor_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned short stdc_bit_floor_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_bit_floor_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned long stdc_bit_floor_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* Bit Ceiling
*/
extern unsigned char stdc_bit_ceil_uc(unsigned char) _C23_UNSEQ_ATTR;
extern unsigned short stdc_bit_ceil_us(unsigned short) _C23_UNSEQ_ATTR;
extern unsigned int stdc_bit_ceil_ui(unsigned int) _C23_UNSEQ_ATTR;
extern unsigned long stdc_bit_ceil_ul(unsigned long) _C23_UNSEQ_ATTR;
/*
* long long variants of functions. This check is just for some non-C23
* environments out of courtesy.
*/
#if defined(_LONGLONG_TYPE)
extern unsigned int stdc_leading_zeros_ull(unsigned long long) _C23_UNSEQ_ATTR;
extern unsigned int stdc_leading_ones_ull(unsigned long long) _C23_UNSEQ_ATTR;
extern unsigned int stdc_trailing_zeros_ull(unsigned long long) _C23_UNSEQ_ATTR;
extern unsigned int stdc_trailing_ones_ull(unsigned long long) _C23_UNSEQ_ATTR;
extern unsigned int stdc_first_leading_zero_ull(unsigned long long)
_C23_UNSEQ_ATTR;
extern unsigned int stdc_first_leading_one_ull(unsigned long long)
_C23_UNSEQ_ATTR;
extern unsigned int stdc_first_trailing_zero_ull(unsigned long long)
_C23_UNSEQ_ATTR;
extern unsigned int stdc_first_trailing_one_ull(unsigned long long)
_C23_UNSEQ_ATTR;
extern unsigned int stdc_count_zeros_ull(unsigned long long) _C23_UNSEQ_ATTR;
extern unsigned int stdc_count_ones_ull(unsigned long long) _C23_UNSEQ_ATTR;
extern bool stdc_has_single_bit_ull(unsigned long long) _C23_UNSEQ_ATTR;
extern unsigned int stdc_bit_width_ull(unsigned long long) _C23_UNSEQ_ATTR;
extern unsigned long long stdc_bit_floor_ull(unsigned long long)
_C23_UNSEQ_ATTR;
extern unsigned long long stdc_bit_ceil_ull(unsigned long long) _C23_UNSEQ_ATTR;
#endif /* _LONGLONG_TYPE */
/*
* Type Generic functions. The standard requires that these be a generic return
* type that operates on the following types of values:
*
* - Standard unsigned integer types (excluding bool) i.e. 'unsigned int'.
* - Extended unsigned integer types i.e. 'uint128_t' which is not something
* currently supported and up to the platform.
* - Bit-precise integers that match standard or extended integers. This means
* that _BitInt(32) is accepted, but a value that basically doesn't match a
* uint8_t, uint16_t, uint32_t, or uint64_t like _BitInt(48) is not valid.
*
* There currently is no way to match ranges of _BitInt in the _Generic macro so
* we end up focusing on the size of the type that was passed. _Generic matches
* on the type of the first expression, so rather than just the base type of the
* value, we instead use a suggestion to transform it into a fixed-length array.
* This works for signed and unsigned integers, implicitly doing a cast to the
* unsigned value for signed integers. Similarly, this incidentally works for
* signed and unsigned _BitInt() values that are able to be translated into
* standard sizes. We always use the ull versions for 64-bit values as that is
* always 64-bit regardless if we're in an ILP32 or LP64 environment.
*
* _Generic was introduced in C11. As we currently don't have any _Generic
* statements that aren't valid in C11, we reduce our guard for these to C11 as
* there isn't really a good way to test for the presence of the _Generic
* construct otherwise. If we end up having to modify these to use more explicit
* types, we'll have to have per-standard versions of these macros.
*/
#if defined(_STDC_C11)
/* CSTYLED */
#define stdc_leading_zeros(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_leading_zeros_uc(val), \
char(*)[2]: stdc_leading_zeros_us(val), \
char(*)[4]: stdc_leading_zeros_ui(val), \
char(*)[8]: stdc_leading_zeros_ull(val))
/* CSTYLED */
#define stdc_leading_ones(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_leading_ones_uc(val), \
char(*)[2]: stdc_leading_ones_us(val), \
char(*)[4]: stdc_leading_ones_ui(val), \
char(*)[8]: stdc_leading_ones_ull(val))
/* CSTYLED */
#define stdc_trailing_zeros(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_trailing_zeros_uc(val), \
char(*)[2]: stdc_trailing_zeros_us(val), \
char(*)[4]: stdc_trailing_zeros_ui(val), \
char(*)[8]: stdc_trailing_zeros_ull(val))
/* CSTYLED */
#define stdc_trailing_ones(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_trailing_ones_uc(val), \
char(*)[2]: stdc_trailing_ones_us(val), \
char(*)[4]: stdc_trailing_ones_ui(val), \
char(*)[8]: stdc_trailing_ones_ull(val))
/* CSTYLED */
#define stdc_first_leading_zero(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_first_leading_zero_uc(val), \
char(*)[2]: stdc_first_leading_zero_us(val), \
char(*)[4]: stdc_first_leading_zero_ui(val), \
char(*)[8]: stdc_first_leading_zero_ull(val))
/* CSTYLED */
#define stdc_first_leading_one(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_first_leading_one_uc(val), \
char(*)[2]: stdc_first_leading_one_us(val), \
char(*)[4]: stdc_first_leading_one_ui(val), \
char(*)[8]: stdc_first_leading_one_ull(val))
/* CSTYLED */
#define stdc_first_trailing_zero(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_first_trailing_zero_uc(val), \
char(*)[2]: stdc_first_trailing_zero_us(val), \
char(*)[4]: stdc_first_trailing_zero_ui(val), \
char(*)[8]: stdc_first_trailing_zero_ull(val))
/* CSTYLED */
#define stdc_first_trailing_one(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_first_trailing_one_uc(val), \
char(*)[2]: stdc_first_trailing_one_us(val), \
char(*)[4]: stdc_first_trailing_one_ui(val), \
char(*)[8]: stdc_first_trailing_one_ull(val))
/* CSTYLED */
#define stdc_count_zeros(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_count_zeros_uc(val), \
char(*)[2]: stdc_count_zeros_us(val), \
char(*)[4]: stdc_count_zeros_ui(val), \
char(*)[8]: stdc_count_zeros_ull(val))
/* CSTYLED */
#define stdc_count_ones(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_count_ones_uc(val), \
char(*)[2]: stdc_count_ones_us(val), \
char(*)[4]: stdc_count_ones_ui(val), \
char(*)[8]: stdc_count_ones_ull(val))
/* CSTYLED */
#define stdc_has_single_bit(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_has_single_bit_uc(val), \
char(*)[2]: stdc_has_single_bit_us(val), \
char(*)[4]: stdc_has_single_bit_ui(val), \
char(*)[8]: stdc_has_single_bit_ull(val))
/* CSTYLED */
#define stdc_bit_width(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_bit_width_uc(val), \
char(*)[2]: stdc_bit_width_us(val), \
char(*)[4]: stdc_bit_width_ui(val), \
char(*)[8]: stdc_bit_width_ull(val))
/* CSTYLED */
#define stdc_bit_floor(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_bit_floor_uc(val), \
char(*)[2]: stdc_bit_floor_us(val), \
char(*)[4]: stdc_bit_floor_ui(val), \
char(*)[8]: stdc_bit_floor_ull(val))
/* CSTYLED */
#define stdc_bit_ceil(val) _Generic((char(*)[sizeof (val)]){ 0 }, \
char(*)[1]: stdc_bit_ceil_uc(val), \
char(*)[2]: stdc_bit_ceil_us(val), \
char(*)[4]: stdc_bit_ceil_ui(val), \
char(*)[8]: stdc_bit_ceil_ull(val))
#endif /* STDC_C11 */
#ifdef __cplusplus
}
#endif
#endif /* _SYS_STDBIT_H */
|