boost/dynamic_bitset/detail/dynamic_bitset.hpp
// -----------------------------------------------------------
//
// Copyright (c) 2001-2002 Chuck Allison and Jeremy Siek
// Copyright (c) 2003-2006, 2008 Gennaro Prota
// Copyright (c) 2014 Glen Joseph Fernandes
// (glenjofe@gmail.com)
// Copyright (c) 2018 Evgeny Shulgin
// Copyright (c) 2019 Andrey Semashev
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// -----------------------------------------------------------
#ifndef BOOST_DETAIL_DYNAMIC_BITSET_HPP
#define BOOST_DETAIL_DYNAMIC_BITSET_HPP
#include <memory>
#include <cstddef>
#include "boost/config.hpp"
#include "boost/detail/workaround.hpp"
#if ((defined(BOOST_MSVC) && (BOOST_MSVC >= 1600)) || (defined(__clang__) && defined(__c2__)) || (defined(BOOST_INTEL) && defined(_MSC_VER))) && (defined(_M_IX86) || defined(_M_X64))
#include <intrin.h>
#endif
namespace boost {
namespace detail {
namespace dynamic_bitset_impl {
// Gives (read-)access to the object representation
// of an object of type T (3.9p4). CANNOT be used
// on a base sub-object
//
template <typename T>
inline const unsigned char * object_representation (T* p)
{
return static_cast<const unsigned char *>(static_cast<const void *>(p));
}
template<typename T, int amount, int width /* = default */>
struct shifter
{
static void left_shift(T & v) {
amount >= width ? (v = 0)
: (v >>= BOOST_DYNAMIC_BITSET_WRAP_CONSTANT(amount));
}
};
// ------- count function implementation --------------
typedef unsigned char byte_type;
// These two entities
//
// enum mode { access_by_bytes, access_by_blocks };
// template <mode> struct mode_to_type {};
//
// were removed, since the regression logs (as of 24 Aug 2008)
// showed that several compilers had troubles with recognizing
//
// const mode m = access_by_bytes
//
// as a constant expression
//
// * So, we'll use bool, instead of enum *.
//
template <bool value>
struct value_to_type
{
value_to_type() {}
};
const bool access_by_bytes = true;
const bool access_by_blocks = false;
// the table: wrapped in a class template, so
// that it is only instantiated if/when needed
//
template <bool dummy_name = true>
struct count_table { static const byte_type table[]; };
template <>
struct count_table<false> { /* no table */ };
const unsigned int table_width = 8;
template <bool b>
const byte_type count_table<b>::table[] =
{
// Automatically generated by GPTableGen.exe v.1.0
//
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
};
// Some platforms have fast popcount operation, that allow us to implement
// counting bits much more efficiently
//
template <typename ValueType>
BOOST_FORCEINLINE std::size_t popcount(ValueType value) BOOST_NOEXCEPT
{
std::size_t num = 0u;
while (value) {
num += count_table<>::table[value & ((1u<<table_width) - 1)];
value >>= table_width;
}
return num;
}
#if (((defined(BOOST_MSVC) && (BOOST_MSVC >= 1600)) || (defined(__clang__) && defined(__c2__)) || (defined(BOOST_INTEL) && defined(_MSC_VER))) && (defined(_M_IX86) || defined(_M_X64))) \
&& (defined(__POPCNT__) || defined(__AVX__))
template <>
BOOST_FORCEINLINE std::size_t popcount<unsigned short>(unsigned short value) BOOST_NOEXCEPT
{
return static_cast<std::size_t>(__popcnt16(value));
}
template <>
BOOST_FORCEINLINE std::size_t popcount<unsigned int>(unsigned int value) BOOST_NOEXCEPT
{
return static_cast<std::size_t>(__popcnt(value));
}
template <>
BOOST_FORCEINLINE std::size_t popcount<unsigned __int64>(unsigned __int64 value) BOOST_NOEXCEPT
{
#if defined(_M_X64)
return static_cast<std::size_t>(__popcnt64(value));
#else
return static_cast<std::size_t>(__popcnt(static_cast< unsigned int >(value))) + static_cast<std::size_t>(__popcnt(static_cast< unsigned int >(value >> 32)));
#endif
}
#elif defined(BOOST_GCC) || defined(__clang__) || (defined(BOOST_INTEL) && defined(__GNUC__))
// Note: gcc builtins are implemented by compiler runtime when the target CPU may not support the necessary instructions
template <>
BOOST_FORCEINLINE std::size_t popcount<unsigned short>(unsigned short value) BOOST_NOEXCEPT
{
return static_cast<unsigned int>(__builtin_popcount(static_cast<unsigned int>(value)));
}
template <>
BOOST_FORCEINLINE std::size_t popcount<unsigned int>(unsigned int value) BOOST_NOEXCEPT
{
return static_cast<unsigned int>(__builtin_popcount(value));
}
template <>
BOOST_FORCEINLINE std::size_t popcount<unsigned long>(unsigned long value) BOOST_NOEXCEPT
{
return static_cast<unsigned int>(__builtin_popcountl(value));
}
template <>
BOOST_FORCEINLINE std::size_t popcount<boost::ulong_long_type>(boost::ulong_long_type value) BOOST_NOEXCEPT
{
return static_cast<unsigned int>(__builtin_popcountll(value));
}
#endif
// overload for access by blocks
//
template <typename Iterator, typename ValueType>
inline std::size_t do_count(Iterator first, std::size_t length, ValueType,
value_to_type<access_by_blocks>*)
{
std::size_t num1 = 0u, num2 = 0u;
while (length >= 2u) {
num1 += popcount<ValueType>(*first);
++first;
num2 += popcount<ValueType>(*first);
++first;
length -= 2u;
}
if (length > 0u)
num1 += popcount<ValueType>(*first);
return num1 + num2;
}
// overload for access by bytes
//
template <typename Iterator>
inline std::size_t do_count(Iterator first, std::size_t length,
int /*dummy param*/,
value_to_type<access_by_bytes>*)
{
if (length > 0u) {
const byte_type* p = object_representation(&*first);
length *= sizeof(*first);
return do_count(p, length, static_cast<byte_type>(0u),
static_cast< value_to_type<access_by_blocks>* >(0));
}
return 0u;
}
// -------------------------------------------------------
// Some library implementations simply return a dummy
// value such as
//
// size_type(-1) / sizeof(T)
//
// from vector<>::max_size. This tries to get more
// meaningful info.
//
template <typename T>
inline typename T::size_type vector_max_size_workaround(const T & v)
BOOST_NOEXCEPT
{
typedef typename T::allocator_type allocator_type;
const allocator_type& alloc = v.get_allocator();
#if !defined(BOOST_NO_CXX11_ALLOCATOR)
typedef std::allocator_traits<allocator_type> allocator_traits;
const typename allocator_traits::size_type alloc_max =
allocator_traits::max_size(alloc);
#else
const typename allocator_type::size_type alloc_max = alloc.max_size();
#endif
const typename T::size_type container_max = v.max_size();
return alloc_max < container_max ? alloc_max : container_max;
}
// for static_asserts
template <typename T>
struct allowed_block_type {
enum { value = T(-1) > 0 }; // ensure T has no sign
};
template <>
struct allowed_block_type<bool> {
enum { value = false };
};
template <typename T>
struct is_numeric {
enum { value = false };
};
# define BOOST_dynamic_bitset_is_numeric(x) \
template<> \
struct is_numeric< x > { \
enum { value = true }; \
} /**/
BOOST_dynamic_bitset_is_numeric(bool);
BOOST_dynamic_bitset_is_numeric(char);
#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
BOOST_dynamic_bitset_is_numeric(wchar_t);
#endif
BOOST_dynamic_bitset_is_numeric(signed char);
BOOST_dynamic_bitset_is_numeric(short int);
BOOST_dynamic_bitset_is_numeric(int);
BOOST_dynamic_bitset_is_numeric(long int);
BOOST_dynamic_bitset_is_numeric(unsigned char);
BOOST_dynamic_bitset_is_numeric(unsigned short);
BOOST_dynamic_bitset_is_numeric(unsigned int);
BOOST_dynamic_bitset_is_numeric(unsigned long);
#if defined(BOOST_HAS_LONG_LONG)
BOOST_dynamic_bitset_is_numeric(::boost::long_long_type);
BOOST_dynamic_bitset_is_numeric(::boost::ulong_long_type);
#endif
// intentionally omitted
//BOOST_dynamic_bitset_is_numeric(float);
//BOOST_dynamic_bitset_is_numeric(double);
//BOOST_dynamic_bitset_is_numeric(long double);
#undef BOOST_dynamic_bitset_is_numeric
} // dynamic_bitset_impl
} // namespace detail
} // namespace boost
#endif // include guard