146 lines
4.6 KiB
C++
146 lines
4.6 KiB
C++
// -*- C++ -*-
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef _LIBCPP___BITS
|
|
#define _LIBCPP___BITS
|
|
|
|
#include <__config>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
#pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_PUSH_MACROS
|
|
#include <__undef_macros>
|
|
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
#ifndef _LIBCPP_COMPILER_MSVC
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
|
|
int __libcpp_ctz(unsigned __x) _NOEXCEPT { return __builtin_ctz(__x); }
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
|
|
int __libcpp_ctz(unsigned long __x) _NOEXCEPT { return __builtin_ctzl(__x); }
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
|
|
int __libcpp_ctz(unsigned long long __x) _NOEXCEPT { return __builtin_ctzll(__x); }
|
|
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
|
|
int __libcpp_clz(unsigned __x) _NOEXCEPT { return __builtin_clz(__x); }
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
|
|
int __libcpp_clz(unsigned long __x) _NOEXCEPT { return __builtin_clzl(__x); }
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
|
|
int __libcpp_clz(unsigned long long __x) _NOEXCEPT { return __builtin_clzll(__x); }
|
|
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
|
|
int __libcpp_popcount(unsigned __x) _NOEXCEPT { return __builtin_popcount(__x); }
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
|
|
int __libcpp_popcount(unsigned long __x) _NOEXCEPT { return __builtin_popcountl(__x); }
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
|
|
int __libcpp_popcount(unsigned long long __x) _NOEXCEPT { return __builtin_popcountll(__x); }
|
|
|
|
#else // _LIBCPP_COMPILER_MSVC
|
|
|
|
// Precondition: __x != 0
|
|
inline _LIBCPP_INLINE_VISIBILITY
|
|
int __libcpp_ctz(unsigned __x) {
|
|
static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
|
|
static_assert(sizeof(unsigned long) == 4, "");
|
|
unsigned long __where;
|
|
if (_BitScanForward(&__where, __x))
|
|
return static_cast<int>(__where);
|
|
return 32;
|
|
}
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY
|
|
int __libcpp_ctz(unsigned long __x) {
|
|
static_assert(sizeof(unsigned long) == sizeof(unsigned), "");
|
|
return __ctz(static_cast<unsigned>(__x));
|
|
}
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY
|
|
int __libcpp_ctz(unsigned long long __x) {
|
|
unsigned long __where;
|
|
#if defined(_LIBCPP_HAS_BITSCAN64)
|
|
if (_BitScanForward64(&__where, __x))
|
|
return static_cast<int>(__where);
|
|
#else
|
|
// Win32 doesn't have _BitScanForward64 so emulate it with two 32 bit calls.
|
|
if (_BitScanForward(&__where, static_cast<unsigned long>(__x)))
|
|
return static_cast<int>(__where);
|
|
if (_BitScanForward(&__where, static_cast<unsigned long>(__x >> 32)))
|
|
return static_cast<int>(__where + 32);
|
|
#endif
|
|
return 64;
|
|
}
|
|
|
|
// Precondition: __x != 0
|
|
inline _LIBCPP_INLINE_VISIBILITY
|
|
int __libcpp_clz(unsigned __x) {
|
|
static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
|
|
static_assert(sizeof(unsigned long) == 4, "");
|
|
unsigned long __where;
|
|
if (_BitScanReverse(&__where, __x))
|
|
return static_cast<int>(31 - __where);
|
|
return 32; // Undefined Behavior.
|
|
}
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY
|
|
int __libcpp_clz(unsigned long __x) {
|
|
static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
|
|
return __libcpp_clz(static_cast<unsigned>(__x));
|
|
}
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY
|
|
int __libcpp_clz(unsigned long long __x) {
|
|
unsigned long __where;
|
|
#if defined(_LIBCPP_HAS_BITSCAN64)
|
|
if (_BitScanReverse64(&__where, __x))
|
|
return static_cast<int>(63 - __where);
|
|
#else
|
|
// Win32 doesn't have _BitScanReverse64 so emulate it with two 32 bit calls.
|
|
if (_BitScanReverse(&__where, static_cast<unsigned long>(__x >> 32)))
|
|
return static_cast<int>(63 - (__where + 32));
|
|
if (_BitScanReverse(&__where, static_cast<unsigned long>(__x)))
|
|
return static_cast<int>(63 - __where);
|
|
#endif
|
|
return 64; // Undefined Behavior.
|
|
}
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY int __libcpp_popcount(unsigned __x) {
|
|
static_assert(sizeof(unsigned) == 4, "");
|
|
return __popcnt(__x);
|
|
}
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY int __libcpp_popcount(unsigned long __x) {
|
|
static_assert(sizeof(unsigned long) == 4, "");
|
|
return __popcnt(__x);
|
|
}
|
|
|
|
inline _LIBCPP_INLINE_VISIBILITY int __libcpp_popcount(unsigned long long __x) {
|
|
static_assert(sizeof(unsigned long long) == 8, "");
|
|
return __popcnt64(__x);
|
|
}
|
|
|
|
#endif // _LIBCPP_COMPILER_MSVC
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
_LIBCPP_POP_MACROS
|
|
|
|
#endif // _LIBCPP___BITS
|