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// -*- C++ -*-
//===------------------------------ bit ----------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===---------------------------------------------------------------------===//
#ifndef _LIBCPP_BIT
#define _LIBCPP_BIT
/*
bit synopsis
namespace std {
} // namespace std
*/
#include <__config>
#include <version>
#if defined(__IBMCPP__)
#include "support/ibm/support.h"
#endif
#if defined(_LIBCPP_COMPILER_MSVC)
#include <intrin.h>
#endif
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#ifndef _LIBCPP_COMPILER_MSVC
inline _LIBCPP_INLINE_VISIBILITY
int __ctz(unsigned __x) { return __builtin_ctz(__x); }
inline _LIBCPP_INLINE_VISIBILITY
int __ctz(unsigned long __x) { return __builtin_ctzl(__x); }
inline _LIBCPP_INLINE_VISIBILITY
int __ctz(unsigned long long __x) { return __builtin_ctzll(__x); }
inline _LIBCPP_INLINE_VISIBILITY
int __clz(unsigned __x) { return __builtin_clz(__x); }
inline _LIBCPP_INLINE_VISIBILITY
int __clz(unsigned long __x) { return __builtin_clzl(__x); }
inline _LIBCPP_INLINE_VISIBILITY
int __clz(unsigned long long __x) { return __builtin_clzll(__x); }
inline _LIBCPP_INLINE_VISIBILITY
int __popcount(unsigned __x) { return __builtin_popcount(__x); }
inline _LIBCPP_INLINE_VISIBILITY
int __popcount(unsigned long __x) { return __builtin_popcountl(__x); }
inline _LIBCPP_INLINE_VISIBILITY
int __popcount(unsigned long long __x) { return __builtin_popcountll(__x); }
#else // _LIBCPP_COMPILER_MSVC
// Precondition: __x != 0
inline _LIBCPP_INLINE_VISIBILITY
int __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 __ctz(unsigned long __x) {
static_assert(sizeof(unsigned long) == sizeof(unsigned), "");
return __ctz(static_cast<unsigned>(__x));
}
inline _LIBCPP_INLINE_VISIBILITY
int __ctz(unsigned long long __x) {
unsigned long __where;
#if defined(_LIBCPP_HAS_BITSCAN64)
(defined(_M_AMD64) || defined(__x86_64__))
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 __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 __clz(unsigned long __x) {
static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
return __clz(static_cast<unsigned>(__x));
}
inline _LIBCPP_INLINE_VISIBILITY
int __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 __popcount(unsigned __x) {
static_assert(sizeof(unsigned) == 4, "");
return __popcnt(__x);
}
inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned long __x) {
static_assert(sizeof(unsigned long) == 4, "");
return __popcnt(__x);
}
inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned long long __x) {
static_assert(sizeof(unsigned long long) == 8, "");
return __popcnt64(__x);
}
#endif // _LIBCPP_COMPILER_MSVC
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_BIT
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