diff options
Diffstat (limited to 'Eigen/src/Core/NumTraits.h')
| -rw-r--r-- | Eigen/src/Core/NumTraits.h | 127 |
1 files changed, 107 insertions, 20 deletions
diff --git a/Eigen/src/Core/NumTraits.h b/Eigen/src/Core/NumTraits.h index daf489878..72eac5a93 100644 --- a/Eigen/src/Core/NumTraits.h +++ b/Eigen/src/Core/NumTraits.h @@ -21,12 +21,14 @@ template< typename T, bool is_integer = NumTraits<T>::IsInteger> struct default_digits10_impl { + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static int run() { return std::numeric_limits<T>::digits10; } }; template<typename T> struct default_digits10_impl<T,false,false> // Floating point { + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static int run() { using std::log10; using std::ceil; @@ -38,11 +40,64 @@ struct default_digits10_impl<T,false,false> // Floating point template<typename T> struct default_digits10_impl<T,false,true> // Integer { + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR + static int run() { return 0; } +}; + + +// default implementation of digits(), based on numeric_limits if specialized, +// 0 for integer types, and log2(epsilon()) otherwise. +template< typename T, + bool use_numeric_limits = std::numeric_limits<T>::is_specialized, + bool is_integer = NumTraits<T>::IsInteger> +struct default_digits_impl +{ + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR + static int run() { return std::numeric_limits<T>::digits; } +}; + +template<typename T> +struct default_digits_impl<T,false,false> // Floating point +{ + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR + static int run() { + using std::log; + using std::ceil; + typedef typename NumTraits<T>::Real Real; + return int(ceil(-log(NumTraits<Real>::epsilon())/log(static_cast<Real>(2)))); + } +}; + +template<typename T> +struct default_digits_impl<T,false,true> // Integer +{ + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static int run() { return 0; } }; } // end namespace internal +namespace numext { +/** \internal bit-wise cast without changing the underlying bit representation. */ + +// TODO: Replace by std::bit_cast (available in C++20) +template <typename Tgt, typename Src> +EIGEN_STRONG_INLINE EIGEN_DEVICE_FUNC Tgt bit_cast(const Src& src) { +#if EIGEN_HAS_TYPE_TRAITS + // The behaviour of memcpy is not specified for non-trivially copyable types + EIGEN_STATIC_ASSERT(std::is_trivially_copyable<Src>::value, THIS_TYPE_IS_NOT_SUPPORTED); + EIGEN_STATIC_ASSERT(std::is_trivially_copyable<Tgt>::value && std::is_default_constructible<Tgt>::value, + THIS_TYPE_IS_NOT_SUPPORTED); +#endif + + EIGEN_STATIC_ASSERT(sizeof(Src) == sizeof(Tgt), THIS_TYPE_IS_NOT_SUPPORTED); + Tgt tgt; + EIGEN_USING_STD(memcpy) + memcpy(&tgt, &src, sizeof(Tgt)); + return tgt; +} +} // namespace numext + /** \class NumTraits * \ingroup Core_Module * @@ -71,7 +126,7 @@ struct default_digits10_impl<T,false,true> // Integer * and to \c 0 otherwise. * \li Enum values ReadCost, AddCost and MulCost representing a rough estimate of the number of CPU cycles needed * to by move / add / mul instructions respectively, assuming the data is already stored in CPU registers. - * Stay vague here. No need to do architecture-specific stuff. + * Stay vague here. No need to do architecture-specific stuff. If you don't know what this means, just use \c Eigen::HugeCost. * \li An enum value \a IsSigned. It is equal to \c 1 if \a T is a signed type and to 0 if \a T is unsigned. * \li An enum value \a RequireInitialization. It is equal to \c 1 if the constructor of the numeric type \a T must * be called, and to 0 if it is safe not to call it. Default is 0 if \a T is an arithmetic type, and 1 otherwise. @@ -80,9 +135,18 @@ struct default_digits10_impl<T,false,true> // Integer * \li A dummy_precision() function returning a weak epsilon value. It is mainly used as a default * value by the fuzzy comparison operators. * \li highest() and lowest() functions returning the highest and lowest possible values respectively. + * \li digits() function returning the number of radix digits (non-sign digits for integers, mantissa for floating-point). This is + * the analogue of <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/digits">std::numeric_limits<T>::digits</a> + * which is used as the default implementation if specialized. * \li digits10() function returning the number of decimal digits that can be represented without change. This is * the analogue of <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/digits10">std::numeric_limits<T>::digits10</a> * which is used as the default implementation if specialized. + * \li min_exponent() and max_exponent() functions returning the highest and lowest possible values, respectively, + * such that the radix raised to the power exponent-1 is a normalized floating-point number. These are equivalent to + * <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/min_exponent">std::numeric_limits<T>::min_exponent</a>/ + * <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/max_exponent">std::numeric_limits<T>::max_exponent</a>. + * \li infinity() function returning a representation of positive infinity, if available. + * \li quiet_NaN function returning a non-signaling "not-a-number", if available. */ template<typename T> struct GenericNumTraits @@ -106,42 +170,60 @@ template<typename T> struct GenericNumTraits typedef T Nested; typedef T Literal; - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline Real epsilon() { return numext::numeric_limits<T>::epsilon(); } - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline int digits10() { return internal::default_digits10_impl<T>::run(); } - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR + static inline int digits() + { + return internal::default_digits_impl<T>::run(); + } + + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR + static inline int min_exponent() + { + return numext::numeric_limits<T>::min_exponent; + } + + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR + static inline int max_exponent() + { + return numext::numeric_limits<T>::max_exponent; + } + + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline Real dummy_precision() { // make sure to override this for floating-point types return Real(0); } - - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline T highest() { return (numext::numeric_limits<T>::max)(); } - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline T lowest() { - return IsInteger ? (numext::numeric_limits<T>::min)() : (-(numext::numeric_limits<T>::max)()); + return IsInteger ? (numext::numeric_limits<T>::min)() + : static_cast<T>(-(numext::numeric_limits<T>::max)()); } - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline T infinity() { return numext::numeric_limits<T>::infinity(); } - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline T quiet_NaN() { return numext::numeric_limits<T>::quiet_NaN(); } @@ -153,19 +235,20 @@ template<typename T> struct NumTraits : GenericNumTraits<T> template<> struct NumTraits<float> : GenericNumTraits<float> { - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline float dummy_precision() { return 1e-5f; } }; template<> struct NumTraits<double> : GenericNumTraits<double> { - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline double dummy_precision() { return 1e-12; } }; template<> struct NumTraits<long double> : GenericNumTraits<long double> { + EIGEN_CONSTEXPR static inline long double dummy_precision() { return 1e-15l; } }; @@ -182,11 +265,11 @@ template<typename _Real> struct NumTraits<std::complex<_Real> > MulCost = 4 * NumTraits<Real>::MulCost + 2 * NumTraits<Real>::AddCost }; - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline Real epsilon() { return NumTraits<Real>::epsilon(); } - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline Real dummy_precision() { return NumTraits<Real>::dummy_precision(); } - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline int digits10() { return NumTraits<Real>::digits10(); } }; @@ -206,16 +289,17 @@ struct NumTraits<Array<Scalar, Rows, Cols, Options, MaxRows, MaxCols> > IsInteger = NumTraits<Scalar>::IsInteger, IsSigned = NumTraits<Scalar>::IsSigned, RequireInitialization = 1, - ReadCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::ReadCost, - AddCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::AddCost, - MulCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::MulCost + ReadCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * int(NumTraits<Scalar>::ReadCost), + AddCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * int(NumTraits<Scalar>::AddCost), + MulCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * int(NumTraits<Scalar>::MulCost) }; - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline RealScalar epsilon() { return NumTraits<RealScalar>::epsilon(); } - EIGEN_DEVICE_FUNC + EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR static inline RealScalar dummy_precision() { return NumTraits<RealScalar>::dummy_precision(); } + EIGEN_CONSTEXPR static inline int digits10() { return NumTraits<Scalar>::digits10(); } }; @@ -229,6 +313,7 @@ template<> struct NumTraits<std::string> MulCost = HugeCost }; + EIGEN_CONSTEXPR static inline int digits10() { return 0; } private: @@ -243,6 +328,8 @@ private: // Empty specialization for void to allow template specialization based on NumTraits<T>::Real with T==void and SFINAE. template<> struct NumTraits<void> {}; +template<> struct NumTraits<bool> : GenericNumTraits<bool> {}; + } // end namespace Eigen #endif // EIGEN_NUMTRAITS_H |