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Convert internal implementation for FixedPoint from decimal to binary #231

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Convert internal implementation for FixedPoint from decimal to binary #231

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9506293
dec to bin
sakamoto-souta Jun 12, 2023
6dbc9d6
fix:maxInt
sakamoto-souta Jun 12, 2023
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38 changes: 11 additions & 27 deletions packages/server/computation_container/fixed_point/fixed_point.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -11,50 +11,34 @@

namespace qmpc::Utils
{
template <typename T, typename U>
inline static constexpr T mypow(T a_, U n_) noexcept
{
T a = a_;
U n = n_;
T ret = 1;
while (n > 0)
{
if (n & 1) ret *= a;
a *= a;
n >>= 1;
}
return ret;
}
namespace mp = boost::multiprecision;
using cpp_dec_float = mp::number<mp::cpp_dec_float<50>>;
/*
T:保持する整数型
D:変換する浮動小数点型
length:10^length が最大値
resolution:10^resolutionを1とする
T : 保持する整数型
D : 変換する浮動小数点型
length : 使用するTのbit長
resolution : 1LL<<resolutionを1とする
*/
template <
typename T = boost::multiprecision::cpp_int,
typename D = cpp_dec_float,
int length = 18,
int resolution = 8>
int length = 60,
int resolution = 27>
class FixedPointImpl : private boost::operators<FixedPointImpl<>>
{
private:
constexpr static long long shift = mypow(10ll, resolution);
constexpr static long long maxInt =
mypow(10ll, length - resolution); // FixedPointImplがとりうる整数の最大値
constexpr static long long shift = 1LL << resolution;
constexpr static long long maxInt = 1LL << (length-resolution); // FixedPointImplがとりうる整数の最大値
T value;

public:
FixedPointImpl() : value(0) {}
FixedPointImpl(const FixedPointImpl &v) : value(v.value) {}
FixedPointImpl(FixedPointImpl &&v) : value(std::move(v.value)) {}
template <
typename U,
std::enable_if_t<
std::is_arithmetic_v<
std::remove_reference_t<U>> or std::is_convertible_v<T, std::remove_reference_t<U>>,
std::is_arithmetic_v<std::remove_reference_t<U>>
or std::is_convertible_v<T, std::remove_reference_t<U>>,
std::nullptr_t> = nullptr>
FixedPointImpl(const U &v)
{
Expand Down Expand Up @@ -171,7 +155,7 @@ class FixedPointImpl : private boost::operators<FixedPointImpl<>>
}
/*
TODO:
オーバーフローの可能性が10^shift^2 = 10^12の掛け算でかなり高くなってしまうので
オーバーフローの可能性が shift^2 = 1LL<<54 の掛け算でかなり高くなってしまうので
一時的に浮動小数点に戻してから演算を行うことも考慮しておく
*/
FixedPointImpl &operator*=(const FixedPointImpl &obj)
Expand Down