config/test/math_info.cpp
2011-02-15 20:41:56 +00:00

366 lines
12 KiB
C++

// (C) Copyright John Maddock 2005.
// 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)
// See http://www.boost.org/libs/config/test for most recent version.
//
// This test prints out informative information about <math.h>, <float.h>
// and <limits>. Note that this file does require a correctly configured
// Boost setup, and so can't be folded into config_info which is designed
// to function without Boost.Confg support. Each test is documented in
// more detail below.
//
#include <boost/limits.hpp>
#include <limits.h>
#include <math.h>
#include <cmath>
#include <float.h>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <boost/type_traits/alignment_of.hpp>
#ifdef BOOST_NO_STDC_NAMESPACE
namespace std{ using ::strcmp; using ::pow; using ::fabs; using ::sqrt; using ::sin; using ::atan2; }
#endif
static unsigned int indent = 4;
static unsigned int width = 40;
void print_macro(const char* name, const char* value)
{
// if name == value+1 then then macro is not defined,
// in which case we don't print anything:
if(0 != std::strcmp(name, value+1))
{
for(unsigned i = 0; i < indent; ++i) std::cout.put(' ');
std::cout << std::setw(width);
std::cout.setf(std::istream::left, std::istream::adjustfield);
std::cout << name;
if(value[1])
{
// macro has a value:
std::cout << value << "\n";
}
else
{
// macro is defined but has no value:
std::cout << " [no value]\n";
}
}
}
#define PRINT_MACRO(X) print_macro(#X, BOOST_STRINGIZE(=X))
template <class T>
void print_expression(const char* expression, T val)
{
for(unsigned i = 0; i < indent; ++i) std::cout.put(' ');
std::cout << std::setw(width);
std::cout.setf(std::istream::left, std::istream::adjustfield);
std::cout << std::setprecision(std::numeric_limits<T>::digits10+2);
std::cout << expression << "=" << val << std::endl;
}
#define PRINT_EXPRESSION(E) print_expression(#E, E);
template <class T>
void print_limits(T, const char* name)
{
//
// Output general information on numeric_limits, as well as
// probing known and supected problems.
//
std::cout <<
"~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"
"std::numeric_limits information for type " << name << std::endl;
std::cout <<
" is_specialized = " << std::numeric_limits<T>::is_specialized << std::endl;
std::cout <<
" min" "() = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::min)() << std::endl;
std::cout <<
" max" "() = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::max)() << std::endl;
std::cout <<
" digits = " << std::numeric_limits<T>::digits << std::endl;
std::cout <<
" digits10 = " << std::numeric_limits<T>::digits10 << std::endl;
std::cout <<
" is_signed = " << std::numeric_limits<T>::is_signed << std::endl;
std::cout <<
" is_integer = " << std::numeric_limits<T>::is_integer << std::endl;
std::cout <<
" is_exact = " << std::numeric_limits<T>::is_exact << std::endl;
std::cout <<
" radix = " << std::numeric_limits<T>::radix << std::endl;
std::cout <<
" epsilon() = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::epsilon)() << std::endl;
std::cout <<
" round_error() = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::round_error)() << std::endl;
std::cout <<
" min_exponent = " << std::numeric_limits<T>::min_exponent << std::endl;
std::cout <<
" min_exponent10 = " << std::numeric_limits<T>::min_exponent10 << std::endl;
std::cout <<
" max_exponent = " << std::numeric_limits<T>::max_exponent << std::endl;
std::cout <<
" max_exponent10 = " << std::numeric_limits<T>::max_exponent10 << std::endl;
std::cout <<
" has_infinity = " << std::numeric_limits<T>::has_infinity << std::endl;
std::cout <<
" has_quiet_NaN = " << std::numeric_limits<T>::has_quiet_NaN << std::endl;
std::cout <<
" has_signaling_NaN = " << std::numeric_limits<T>::has_signaling_NaN << std::endl;
std::cout <<
" has_denorm = " << std::numeric_limits<T>::has_denorm << std::endl;
std::cout <<
" has_denorm_loss = " << std::numeric_limits<T>::has_denorm_loss << std::endl;
std::cout <<
" infinity() = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::infinity)() << std::endl;
std::cout <<
" quiet_NaN() = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::quiet_NaN)() << std::endl;
std::cout <<
" signaling_NaN() = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::signaling_NaN)() << std::endl;
std::cout <<
" denorm_min() = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::denorm_min)() << std::endl;
std::cout <<
" is_iec559 = " << std::numeric_limits<T>::is_iec559 << std::endl;
std::cout <<
" is_bounded = " << std::numeric_limits<T>::is_bounded << std::endl;
std::cout <<
" is_modulo = " << std::numeric_limits<T>::is_modulo << std::endl;
std::cout <<
" traps = " << std::numeric_limits<T>::traps << std::endl;
std::cout <<
" tinyness_before = " << std::numeric_limits<T>::tinyness_before << std::endl;
std::cout <<
" round_style = " << std::numeric_limits<T>::round_style << std::endl << std::endl;
if(std::numeric_limits<T>::is_exact == 0)
{
bool r = std::numeric_limits<T>::epsilon() == std::pow(static_cast<T>(std::numeric_limits<T>::radix), 1-std::numeric_limits<T>::digits);
if(r)
std::cout << "Epsilon has sane value of std::pow(std::numeric_limits<T>::radix, 1-std::numeric_limits<T>::digits)." << std::endl;
else
std::cout << "CAUTION: epsilon does not have a sane value." << std::endl;
std::cout << std::endl;
}
std::cout <<
" sizeof(" << name << ") = " << sizeof(T) << std::endl;
std::cout <<
" alignment_of<" << name << "> = " << boost::alignment_of<T>::value << std::endl << std::endl;
}
/*
template <class T>
bool is_same_type(T, T)
{
return true;
}*/
bool is_same_type(float, float)
{ return true; }
bool is_same_type(double, double)
{ return true; }
bool is_same_type(long double, long double)
{ return true; }
template <class T, class U>
bool is_same_type(T, U)
{
return false;
}
//
// We need this to test whether abs has been overloaded for
// the floating point types or not:
//
namespace std{
#if !BOOST_WORKAROUND(BOOST_MSVC, == 1300) && \
!defined(_LIBCPP_VERSION)
template <class T>
char abs(T)
{
return ' ';
}
#endif
}
template <class T>
void test_overloads(T, const char* name)
{
//
// Probe known and suspected problems with the std lib Math functions.
//
std::cout <<
"~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"
"Math function overload information for type " << name << std::endl;
//
// Are the math functions overloaded for type T,
// or do we just get double versions?
//
bool r = is_same_type(std::fabs(T(0)), T(0));
r &= is_same_type(std::sqrt(T(0)), T(0));
r &= is_same_type(std::sin(T(0)), T(0));
if(r)
std::cout << "The Math functions are overloaded for type " << name << std::endl;
else
std::cout << "CAUTION: The Math functions are NOT overloaded for type " << name << std::endl;
//
// Check that a few of the functions work OK, we do this because if these
// are implemented as double precision internally then we can get
// overflow or underflow when passing arguments of other types.
//
r = (std::fabs((std::numeric_limits<T>::max)()) == (std::numeric_limits<T>::max)());
r &= (std::fabs(-(std::numeric_limits<T>::max)()) == (std::numeric_limits<T>::max)());
r &= (std::fabs((std::numeric_limits<T>::min)()) == (std::numeric_limits<T>::min)());
r &= (std::fabs(-(std::numeric_limits<T>::min)()) == (std::numeric_limits<T>::min)());
if(r)
std::cout << "std::fabs looks OK for type " << name << std::endl;
else
std::cout << "CAUTION: std::fabs is broken for type " << name << std::endl;
//
// abs not overloaded for real arguments with VC6 (and others?)
//
r = (std::abs((std::numeric_limits<T>::max)()) == (std::numeric_limits<T>::max)());
r &= (std::abs(-(std::numeric_limits<T>::max)()) == (std::numeric_limits<T>::max)());
r &= (std::abs((std::numeric_limits<T>::min)()) == (std::numeric_limits<T>::min)());
r &= (std::abs(-(std::numeric_limits<T>::min)()) == (std::numeric_limits<T>::min)());
if(r)
std::cout << "std::abs looks OK for type " << name << std::endl;
else
std::cout << "CAUTION: std::abs is broken for type " << name << std::endl;
//
// std::sqrt on FreeBSD converts long double arguments to double leading to
// overflow/underflow:
//
r = (std::sqrt((std::numeric_limits<T>::max)()) < (std::numeric_limits<T>::max)());
if(r)
std::cout << "std::sqrt looks OK for type " << name << std::endl;
else
std::cout << "CAUTION: std::sqrt is broken for type " << name << std::endl;
//
// Sanity check for atan2: verify that it returns arguments in the correct
// range and not just atan(x/y).
//
static const T half_pi = static_cast<T>(1.57079632679489661923132169163975144L);
T val = std::atan2(T(-1), T(-1));
r = -half_pi > val;
val = std::atan2(T(1), T(-1));
r &= half_pi < val;
val = std::atan2(T(1), T(1));
r &= (val > 0) && (val < half_pi);
val = std::atan2(T(-1), T(1));
r &= (val < 0) && (val > -half_pi);
if(r)
std::cout << "std::atan2 looks OK for type " << name << std::endl;
else
std::cout << "CAUTION: std::atan2 is broken for type " << name << std::endl;
}
int main()
{
//
// Start by printing the values of the macros from float.h
//
std::cout <<
"~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"
"Macros from <math.h>" << std::endl;
#ifdef __BORLANDC__
// Turn off hardware exceptions so we don't just abort
// when calling numeric_limits members.
_control87(MCW_EM,MCW_EM);
#endif
PRINT_EXPRESSION(HUGE_VAL);
#ifdef HUGE_VALF
PRINT_EXPRESSION(HUGE_VALF);
#endif
#ifdef HUGE_VALL
PRINT_EXPRESSION(HUGE_VALL);
#endif
#ifdef INFINITY
PRINT_EXPRESSION(INFINITY);
#endif
PRINT_MACRO(NAN);
PRINT_MACRO(FP_INFINITE);
PRINT_MACRO(FP_NAN);
PRINT_MACRO(FP_NORMAL);
PRINT_MACRO(FP_SUBNORMAL);
PRINT_MACRO(FP_ZERO);
PRINT_MACRO(FP_FAST_FMA);
PRINT_MACRO(FP_FAST_FMAF);
PRINT_MACRO(FP_FAST_FMAL);
PRINT_MACRO(FP_ILOGB0);
PRINT_MACRO(FP_ILOGBNAN);
PRINT_MACRO(MATH_ERRNO);
PRINT_MACRO(MATH_ERREXCEPT);
PRINT_EXPRESSION(FLT_MIN_10_EXP);
PRINT_EXPRESSION(FLT_DIG);
PRINT_EXPRESSION(FLT_MIN_EXP);
PRINT_EXPRESSION(FLT_EPSILON);
PRINT_EXPRESSION(FLT_RADIX);
PRINT_EXPRESSION(FLT_MANT_DIG);
PRINT_EXPRESSION(FLT_ROUNDS);
PRINT_EXPRESSION(FLT_MAX);
PRINT_EXPRESSION(FLT_MAX_10_EXP);
PRINT_EXPRESSION(FLT_MAX_EXP);
PRINT_EXPRESSION(FLT_MIN);
PRINT_EXPRESSION(DBL_DIG);
PRINT_EXPRESSION(DBL_MIN_EXP);
PRINT_EXPRESSION(DBL_EPSILON);
PRINT_EXPRESSION(DBL_MANT_DIG);
PRINT_EXPRESSION(DBL_MAX);
PRINT_EXPRESSION(DBL_MIN);
PRINT_EXPRESSION(DBL_MAX_10_EXP);
PRINT_EXPRESSION(DBL_MAX_EXP);
PRINT_EXPRESSION(DBL_MIN_10_EXP);
PRINT_EXPRESSION(LDBL_MAX_10_EXP);
PRINT_EXPRESSION(LDBL_MAX_EXP);
PRINT_EXPRESSION(LDBL_MIN);
PRINT_EXPRESSION(LDBL_MIN_10_EXP);
PRINT_EXPRESSION(LDBL_DIG);
PRINT_EXPRESSION(LDBL_MIN_EXP);
PRINT_EXPRESSION(LDBL_EPSILON);
PRINT_EXPRESSION(LDBL_MANT_DIG);
PRINT_EXPRESSION(LDBL_MAX);
std::cout << std::endl;
//
// print out numeric_limits info:
//
print_limits(float(0), "float");
print_limits(double(0), "double");
print_limits((long double)(0), "long double");
//
// print out function overload information:
//
test_overloads(float(0), "float");
test_overloads(double(0), "double");
test_overloads((long double)(0), "long double");
return 0;
}