boost/multiprecision/cpp_int/cpp_int_config.hpp
///////////////////////////////////////////////////////////////
// Copyright 2012 - 2021 John Maddock.
// Copyright 2021 Matt Borland.
// Distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt
#ifndef BOOST_MP_CPP_INT_CONFIG_HPP
#define BOOST_MP_CPP_INT_CONFIG_HPP
#include <cstdint>
#include <type_traits>
#include <limits>
#include <boost/multiprecision/detail/standalone_config.hpp>
#include <boost/multiprecision/detail/assert.hpp>
namespace boost {
namespace multiprecision {
namespace detail {
//
// These traits calculate the largest type in the list
// [unsigned] long long, long, int, which has the specified number
// of bits. Note that int_t and uint_t find the first
// member of the above list, not the last. We want the last in the
// list to ensure that mixed arithmetic operations are as efficient
// as possible.
//
template <std::size_t Bits>
struct int_t
{
using exact = typename std::conditional<Bits <= sizeof(signed char) * CHAR_BIT, signed char,
typename std::conditional<Bits <= sizeof(short) * CHAR_BIT, short,
typename std::conditional<Bits <= sizeof(int) * CHAR_BIT, int,
typename std::conditional<Bits <= sizeof(long) * CHAR_BIT, long,
typename std::conditional<Bits <= sizeof(long long) * CHAR_BIT, long long, void
>::type>::type>::type>::type>::type;
using least = typename std::conditional<Bits-1 <= std::numeric_limits<signed char>::digits, signed char,
typename std::conditional<Bits-1 <= std::numeric_limits<short>::digits, short,
typename std::conditional<Bits-1 <= std::numeric_limits<int>::digits, int,
typename std::conditional<Bits-1 <= std::numeric_limits<long>::digits, long,
typename std::conditional<Bits-1 <= std::numeric_limits<long long>::digits, long long, void
>::type>::type>::type>::type>::type;
static_assert(!std::is_same<void, exact>::value && !std::is_same<void, least>::value, "Number of bits does not match any standard data type. \
Please file an issue at https://github.com/boostorg/multiprecision/ referencing this error from cpp_int_config.hpp");
};
template <std::size_t Bits>
struct uint_t
{
using exact = typename std::conditional<Bits <= sizeof(unsigned char) * CHAR_BIT, unsigned char,
typename std::conditional<Bits <= sizeof(unsigned short) * CHAR_BIT, unsigned short,
typename std::conditional<Bits <= sizeof(unsigned int) * CHAR_BIT, unsigned int,
typename std::conditional<Bits <= sizeof(unsigned long) * CHAR_BIT, unsigned long,
typename std::conditional<Bits <= sizeof(unsigned long long) * CHAR_BIT, unsigned long long, void
>::type>::type>::type>::type>::type;
using least = typename std::conditional<Bits <= std::numeric_limits<unsigned char>::digits, unsigned char,
typename std::conditional<Bits <= std::numeric_limits<unsigned short>::digits, unsigned short,
typename std::conditional<Bits <= std::numeric_limits<unsigned int>::digits, unsigned int,
typename std::conditional<Bits <= std::numeric_limits<unsigned long>::digits, unsigned long,
typename std::conditional<Bits <= std::numeric_limits<unsigned long long>::digits, unsigned long long, void
>::type>::type>::type>::type>::type;
static_assert(!std::is_same<void, exact>::value && !std::is_same<void, least>::value, "Number of bits does not match any standard data type. \
Please file an issue at https://github.com/boostorg/multiprecision/ referencing this error from cpp_int_config.hpp");
};
template <std::size_t N>
struct largest_signed_type
{
using type = typename std::conditional<
1 + std::numeric_limits<long long>::digits == N,
long long,
typename std::conditional<
1 + std::numeric_limits<long>::digits == N,
long,
typename std::conditional<
1 + std::numeric_limits<int>::digits == N,
int,
typename int_t<N>::exact>::type>::type>::type;
};
template <std::size_t N>
struct largest_unsigned_type
{
using type = typename std::conditional<
std::numeric_limits<unsigned long long>::digits == N,
unsigned long long,
typename std::conditional<
std::numeric_limits<unsigned long>::digits == N,
unsigned long,
typename std::conditional<
std::numeric_limits<unsigned int>::digits == N,
unsigned int,
typename uint_t<N>::exact>::type>::type>::type;
};
} // namespace detail
#if defined(BOOST_HAS_INT128)
using limb_type = detail::largest_unsigned_type<64>::type;
using signed_limb_type = detail::largest_signed_type<64>::type;
using double_limb_type = boost::multiprecision::uint128_type;
using signed_double_limb_type = boost::multiprecision::int128_type;
constexpr limb_type max_block_10 = 1000000000000000000uLL;
constexpr limb_type digits_per_block_10 = 18;
inline BOOST_MP_CXX14_CONSTEXPR limb_type block_multiplier(std::size_t count)
{
constexpr limb_type values[digits_per_block_10] = {10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000, 10000000000, 100000000000, 1000000000000, 10000000000000, 100000000000000, 1000000000000000, 10000000000000000, 100000000000000000, 1000000000000000000};
BOOST_MP_ASSERT(count < digits_per_block_10);
return values[count];
}
// Can't do formatted IO on an __int128
#define BOOST_MP_NO_DOUBLE_LIMB_TYPE_IO
#else
using limb_type = detail::largest_unsigned_type<32>::type;
using signed_limb_type = detail::largest_signed_type<32>::type ;
using double_limb_type = detail::largest_unsigned_type<64>::type;
using signed_double_limb_type = detail::largest_signed_type<64>::type ;
constexpr limb_type max_block_10 = 1000000000;
constexpr limb_type digits_per_block_10 = 9;
inline limb_type block_multiplier(std::size_t count)
{
constexpr limb_type values[digits_per_block_10] = {10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000};
BOOST_MP_ASSERT(count < digits_per_block_10);
return values[count];
}
#endif
constexpr std::size_t bits_per_limb = sizeof(limb_type) * CHAR_BIT;
template <class T>
inline BOOST_MP_CXX14_CONSTEXPR void minmax(const T& a, const T& b, T& aa, T& bb)
{
if (a < b)
{
aa = a;
bb = b;
}
else
{
aa = b;
bb = a;
}
}
} // namespace multiprecision
} // namespace boost
#endif // BOOST_MP_CPP_INT_CONFIG_HPP