boost/math/special_functions/fpclassify.hpp
// Copyright John Maddock 2005-2006.
// Use, modification and distribution are subject to 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_MATH_FPCLASSIFY_HPP
#define BOOST_MATH_FPCLASSIFY_HPP
#ifdef _MSC_VER
#pragma once
#endif
#include <math.h>
#include <cmath>
#include <boost/limits.hpp>
#include <boost/math/tools/real_cast.hpp>
#include <boost/type_traits/is_floating_point.hpp>
#include <boost/math/special_functions/math_fwd.hpp>
#if defined(_MSC_VER) || defined(__BORLANDC__)
#include <float.h>
#endif
#ifdef BOOST_NO_STDC_NAMESPACE
namespace std{ using ::abs; using ::fabs; }
#endif
#ifndef FP_NORMAL
#define FP_ZERO 0
#define FP_NORMAL 1
#define FP_INFINITE 2
#define FP_NAN 3
#define FP_SUBNORMAL 4
#else
#define BOOST_HAS_FPCLASSIFY
#ifndef fpclassify
# if (defined(__GLIBCPP__) || defined(__GLIBCXX__)) \
&& defined(_GLIBCXX_USE_C99_MATH) \
&& !(defined(_GLIBCXX_USE_C99_FP_MACROS_DYNAMIC) \
&& (_GLIBCXX_USE_C99_FP_MACROS_DYNAMIC != 0))
# ifdef _STLP_VENDOR_CSTD
# define BOOST_FPCLASSIFY_PREFIX ::_STLP_VENDOR_CSTD::
# else
# define BOOST_FPCLASSIFY_PREFIX ::std::
# endif
# else
# undef BOOST_HAS_FPCLASSIFY
# define BOOST_FPCLASSIFY_PREFIX
# endif
#elif (defined(__HP_aCC) && !defined(__hppa))
// aCC 6 appears to do "#define fpclassify fpclassify" which messes us up a bit!
# define BOOST_FPCLASSIFY_PREFIX ::
#else
# define BOOST_FPCLASSIFY_PREFIX
#endif
#ifdef __MINGW32__
# undef BOOST_HAS_FPCLASSIFY
#endif
#endif
namespace boost{
#if defined(BOOST_HAS_FPCLASSIFY) || defined(isnan)
//
// This must not be located in any namespace under boost::math
// otherwise we can get into an infinite loop if isnan is
// a #define for "isnan" !
//
namespace math_detail{
template <class T>
inline bool is_nan_helper(T t, const boost::true_type&)
{
#ifdef isnan
return isnan(t);
#else // BOOST_HAS_FPCLASSIFY
return (BOOST_FPCLASSIFY_PREFIX fpclassify(t) == (int)FP_NAN);
#endif
}
template <class T>
inline bool is_nan_helper(T t, const boost::false_type&)
{
return false;
}
}
#endif // defined(BOOST_HAS_FPCLASSIFY) || defined(isnan)
namespace math{
namespace detail{
template <class T>
inline int fpclassify_imp BOOST_NO_MACRO_EXPAND(T t, const mpl::true_&)
{
// whenever possible check for Nan's first:
#ifdef BOOST_HAS_FPCLASSIFY
if(::boost::math_detail::is_nan_helper(t, ::boost::is_floating_point<T>()))
return FP_NAN;
#elif defined(isnan)
if(boost::math_detail::is_nan_helper(t, ::boost::is_floating_point<T>()))
return FP_NAN;
#elif defined(_MSC_VER) || defined(__BORLANDC__)
if(::_isnan(boost::math::tools::real_cast<double>(t)))
return FP_NAN;
#endif
// std::fabs broken on a few systems especially for long long!!!!
T at = (t < T(0)) ? -t : t;
// Use a process of exclusion to figure out
// what kind of type we have, this relies on
// IEEE conforming reals that will treat
// Nan's as unordered. Some compilers
// don't do this once optimisations are
// turned on, hence the check for nan's above.
if(at <= (std::numeric_limits<T>::max)())
{
if(at >= (std::numeric_limits<T>::min)())
return FP_NORMAL;
return (at != 0) ? FP_SUBNORMAL : FP_ZERO;
}
else if(at > (std::numeric_limits<T>::max)())
return FP_INFINITE;
return FP_NAN;
}
template <class T>
inline int fpclassify_imp BOOST_NO_MACRO_EXPAND(T t, const mpl::false_&)
{
//
// An unknown type with no numeric_limits support,
// so what are we supposed to do we do here?
//
return t == 0 ? FP_ZERO : FP_NORMAL;
}
} // namespace detail
template <class T>
inline int fpclassify BOOST_NO_MACRO_EXPAND(T t)
{
#ifdef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS
if(std::numeric_limits<T>::is_specialized)
return detail::fpclassify_imp(t, mpl::true_());
return detail::fpclassify_imp(t, mpl::false_());
#else
return detail::fpclassify_imp(t, mpl::bool_< ::std::numeric_limits<T>::is_specialized>());
#endif
}
#if defined(BOOST_HAS_FPCLASSIFY)
inline int fpclassify BOOST_NO_MACRO_EXPAND(float t)
{
return BOOST_FPCLASSIFY_PREFIX fpclassify(t);
}
inline int fpclassify BOOST_NO_MACRO_EXPAND(double t)
{
return BOOST_FPCLASSIFY_PREFIX fpclassify(t);
}
#if !defined(__CYGWIN__) && !defined(__HP_aCC) && !defined(BOOST_INTEL) && !defined(BOOST_NO_NATIVE_LONG_DOUBLE_FP_CLASSIFY)
// The native fpclassify broken for long doubles with aCC
// use portable one instead....
inline int fpclassify BOOST_NO_MACRO_EXPAND(long double t)
{
return BOOST_FPCLASSIFY_PREFIX fpclassify(t);
}
#endif
#elif defined(_MSC_VER)
// This only works for type double, for both float
// and long double it gives misleading answers.
inline int fpclassify BOOST_NO_MACRO_EXPAND(double t)
{
switch(::_fpclass(t))
{
case _FPCLASS_SNAN /* Signaling NaN */ :
case _FPCLASS_QNAN /* Quiet NaN */ :
return FP_NAN;
case _FPCLASS_NINF /*Negative infinity ( -INF) */ :
case _FPCLASS_PINF /* Positive infinity (+INF) */ :
return FP_INFINITE;
case _FPCLASS_NN /* Negative normalized non-zero */ :
case _FPCLASS_PN /* Positive normalized non-zero */ :
return FP_NORMAL;
case _FPCLASS_ND /* Negative denormalized */:
case _FPCLASS_PD /* Positive denormalized */ :
return FP_SUBNORMAL;
case _FPCLASS_NZ /* Negative zero ( - 0) */ :
case _FPCLASS_PZ /* Positive 0 (+0) */ :
return FP_ZERO;
default:
/**/ ;
}
return FP_NAN; // should never get here!!!
}
#endif
template <class T>
inline bool isfinite BOOST_NO_MACRO_EXPAND(T z)
{
int t = (::boost::math::fpclassify)(z);
return (t != (int)FP_NAN) && (t != (int)FP_INFINITE);
}
template <class T>
inline bool isinf BOOST_NO_MACRO_EXPAND(T t)
{
return (::boost::math::fpclassify)(t) == (int)FP_INFINITE;
}
template <class T>
inline bool isnan BOOST_NO_MACRO_EXPAND(T t)
{
return (::boost::math::fpclassify)(t) == (int)FP_NAN;
}
#ifdef isnan
template <> inline bool isnan BOOST_NO_MACRO_EXPAND<float>(float t){ return ::boost::math_detail::is_nan_helper(t, boost::true_type()); }
template <> inline bool isnan BOOST_NO_MACRO_EXPAND<double>(double t){ return ::boost::math_detail::is_nan_helper(t, boost::true_type()); }
template <> inline bool isnan BOOST_NO_MACRO_EXPAND<long double>(long double t){ return ::boost::math_detail::is_nan_helper(t, boost::true_type()); }
#elif defined(BOOST_MSVC)
# pragma warning(push)
# pragma warning(disable: 4800) // forcing value to bool 'true' or 'false'
# pragma warning(disable: 4244) // conversion from 'long double' to 'double',
// No possible loss of data because they are same size.
template <> inline bool isnan BOOST_NO_MACRO_EXPAND<float>(float t){ return _isnan(t); }
template <> inline bool isnan BOOST_NO_MACRO_EXPAND<double>(double t){ return _isnan(t); }
template <> inline bool isnan BOOST_NO_MACRO_EXPAND<long double>(long double t){ return _isnan(t); }
#pragma warning (pop)
#endif
template <class T>
inline bool isnormal BOOST_NO_MACRO_EXPAND(T t)
{
return (::boost::math::fpclassify)(t) == (int)FP_NORMAL;
}
} // namespace math
} // namespace boost
#endif // BOOST_MATH_FPCLASSIFY_HPP