multiprecision/detail/fpclassify.hpp

0001 ///////////////////////////////////////////////////////////////////////////////
0002 //  Copyright 2022 Matt Borland. Distributed under the Boost
0003 //  Software License, Version 1.0. (See accompanying file
0004 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0005
0006 #ifndef BOOST_MP_DETAIL_FPCLASSIFY_HPP
0007 #define BOOST_MP_DETAIL_FPCLASSIFY_HPP
0008
0009 #include <cmath>
0010 #include <limits>
0011 #include <type_traits>
0012 #include <boost/multiprecision/detail/standalone_config.hpp>
0013 #include <boost/multiprecision/detail/float128_functions.hpp>
0014
0015 #ifdef BOOST_MP_MATH_AVAILABLE
0016 #include <boost/math/special_functions/fpclassify.hpp>
0017
0018 #define BOOST_MP_ISNAN(x) (boost::math::isnan)(x)
0019 #define BOOST_MP_ISINF(x) (boost::math::isinf)(x)
0020 #define BOOST_MP_FPCLASSIFY(x) (boost::math::fpclassify)(x)
0021 #define BOOST_MP_ISFINITE(x) (!(boost::math::isnan)(x) && !(boost::math::isinf)(x))
0022
0023 #else
0024
0025 namespace boost { namespace multiprecision { namespace detail {
0026
0027 template <typename T, typename std::enable_if<std::is_floating_point<T>::value
0028                       #ifdef BOOST_HAS_FLOAT128
0029                       || std::is_same<T, float128_type>::value
0030                       #endif
0031                       , bool>::type = true>
0032 inline bool isnan BOOST_PREVENT_MACRO_SUBSTITUTION (const T x)
0033 {
0034     BOOST_MP_FLOAT128_USING;
0035     using std::isnan;
0036     return static_cast<bool>((isnan)(x));
0037 }
0038
0039 template <typename T, typename std::enable_if<!std::is_floating_point<T>::value
0040                       #ifdef BOOST_HAS_FLOAT128
0041                       && !std::is_same<T, float128_type>::value
0042                       #endif
0043                       , bool>::type = true>
0044 inline bool isnan BOOST_PREVENT_MACRO_SUBSTITUTION (const T x)
0045 {
0046     return x != x;
0047 }
0048
0049 template <typename T, typename std::enable_if<std::is_floating_point<T>::value
0050                       #ifdef BOOST_HAS_FLOAT128
0051                       || std::is_same<T, float128_type>::value
0052                       #endif
0053                       , bool>::type = true>
0054 inline bool isinf BOOST_PREVENT_MACRO_SUBSTITUTION (const T x)
0055 {
0056     BOOST_MP_FLOAT128_USING;
0057     using std::isinf;
0058     return static_cast<bool>((isinf)(x));
0059 }
0060
0061 template <typename T, typename std::enable_if<!std::is_floating_point<T>::value
0062                       #ifdef BOOST_HAS_FLOAT128
0063                       && !std::is_same<T, float128_type>::value
0064                       #endif
0065                       , bool>::type = true>
0066 inline bool isinf BOOST_PREVENT_MACRO_SUBSTITUTION (const T x)
0067 {
0068     return x == std::numeric_limits<T>::infinity() || x == -std::numeric_limits<T>::infinity();
0069 }
0070
0071 template <typename T, typename std::enable_if<std::is_floating_point<T>::value, bool>::type = true>
0072 inline int fpclassify BOOST_PREVENT_MACRO_SUBSTITUTION (const T x)
0073 {
0074     using std::fpclassify;
0075     return fpclassify(x);
0076 }
0077
0078 template <typename T, typename std::enable_if<!std::is_floating_point<T>::value, bool>::type = true>
0079 inline int fpclassify BOOST_PREVENT_MACRO_SUBSTITUTION (const T x)
0080 {
0081     BOOST_MP_FLOAT128_USING;
0082     using std::isnan;
0083     using std::isinf;
0084     using std::abs;
0085
0086     return (isnan)(x) ? FP_NAN :
0087            (isinf)(x) ? FP_INFINITE :
0088            abs(x) == T(0) ? FP_ZERO :
0089            abs(x) > 0 && abs(x) < (std::numeric_limits<T>::min)() ? FP_SUBNORMAL : FP_NORMAL;
0090 }
0091
0092 }}} // Namespace boost::multiprecision::detail
0093
0094 #define BOOST_MP_ISNAN(x) (boost::multiprecision::detail::isnan)(x)
0095 #define BOOST_MP_ISINF(x) (boost::multiprecision::detail::isinf)(x)
0096 #define BOOST_MP_FPCLASSIFY(x) (boost::multiprecision::detail::fpclassify)(x)
0097 #define BOOST_MP_ISFINITE(x) (!(boost::multiprecision::detail::isnan)(x) && !(boost::multiprecision::detail::isinf)(x))
0098
0099 #endif
0100
0101 #endif // BOOST_MP_DETAIL_FPCLASSIFY_HPP