math/test/test_next.cpp
2019-08-10 08:50:12 -04:00

274 lines
10 KiB
C++

// (C) Copyright John Maddock 2008.
// 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)
#include <pch.hpp>
#include <boost/math/concepts/real_concept.hpp>
#include <boost/math/tools/test.hpp>
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>
#include <boost/test/tools/floating_point_comparison.hpp>
#include <boost/math/special_functions/next.hpp>
#include <boost/math/special_functions/ulp.hpp>
#include <boost/multiprecision/cpp_bin_float.hpp>
#include <iostream>
#include <iomanip>
#ifdef BOOST_MSVC
#pragma warning(disable:4127)
#endif
#if !defined(_CRAYC) && !defined(__CUDACC__) && (!defined(__GNUC__) || (__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ > 3)))
#if (defined(_M_IX86_FP) && (_M_IX86_FP >= 2)) || defined(__SSE2__) || defined(TEST_SSE2)
#include <float.h>
#include "xmmintrin.h"
#define TEST_SSE2
#endif
#endif
template <class T>
void test_value(const T& val, const char* name)
{
using namespace boost::math;
T upper = tools::max_value<T>();
T lower = -upper;
std::cout << "Testing type " << name << " with initial value " << val << std::endl;
BOOST_CHECK_EQUAL(float_distance(float_next(val), val), -1);
BOOST_CHECK(float_next(val) > val);
BOOST_CHECK_EQUAL(float_distance(float_prior(val), val), 1);
BOOST_CHECK(float_prior(val) < val);
BOOST_CHECK_EQUAL(float_distance((boost::math::nextafter)(val, upper), val), -1);
BOOST_CHECK((boost::math::nextafter)(val, upper) > val);
BOOST_CHECK_EQUAL(float_distance((boost::math::nextafter)(val, lower), val), 1);
BOOST_CHECK((boost::math::nextafter)(val, lower) < val);
BOOST_CHECK_EQUAL(float_distance(float_next(float_next(val)), val), -2);
BOOST_CHECK_EQUAL(float_distance(float_prior(float_prior(val)), val), 2);
BOOST_CHECK_EQUAL(float_distance(float_prior(float_prior(val)), float_next(float_next(val))), 4);
BOOST_CHECK_EQUAL(float_distance(float_prior(float_next(val)), val), 0);
BOOST_CHECK_EQUAL(float_distance(float_next(float_prior(val)), val), 0);
BOOST_CHECK_EQUAL(float_prior(float_next(val)), val);
BOOST_CHECK_EQUAL(float_next(float_prior(val)), val);
BOOST_CHECK_EQUAL(float_distance(float_advance(val, 4), val), -4);
BOOST_CHECK_EQUAL(float_distance(float_advance(val, -4), val), 4);
if(std::numeric_limits<T>::is_specialized && (std::numeric_limits<T>::has_denorm == std::denorm_present))
{
BOOST_CHECK_EQUAL(float_distance(float_advance(float_next(float_next(val)), 4), float_next(float_next(val))), -4);
BOOST_CHECK_EQUAL(float_distance(float_advance(float_next(float_next(val)), -4), float_next(float_next(val))), 4);
}
if(val > 0)
{
T n = val + ulp(val);
T fn = float_next(val);
if(n > fn)
{
BOOST_CHECK_LE(ulp(val), boost::math::tools::min_value<T>());
}
else
{
BOOST_CHECK_EQUAL(fn, n);
}
}
else if(val == 0)
{
BOOST_CHECK_GE(boost::math::tools::min_value<T>(), ulp(val));
}
else
{
T n = val - ulp(val);
T fp = float_prior(val);
if(n < fp)
{
BOOST_CHECK_LE(ulp(val), boost::math::tools::min_value<T>());
}
else
{
BOOST_CHECK_EQUAL(fp, n);
}
}
}
template <class T>
void test_values(const T& val, const char* name)
{
static const T a = static_cast<T>(1.3456724e22);
static const T b = static_cast<T>(1.3456724e-22);
static const T z = 0;
static const T one = 1;
static const T two = 2;
std::cout << "Testing type " << name << std::endl;
T den = (std::numeric_limits<T>::min)() / 4;
if(den != 0)
{
std::cout << "Denormals are active\n";
}
else
{
std::cout << "Denormals are flushed to zero.\n";
}
test_value(a, name);
test_value(-a, name);
test_value(b, name);
test_value(-b, name);
test_value(boost::math::tools::epsilon<T>(), name);
test_value(-boost::math::tools::epsilon<T>(), name);
test_value(boost::math::tools::min_value<T>(), name);
test_value(-boost::math::tools::min_value<T>(), name);
if (std::numeric_limits<T>::is_specialized && (std::numeric_limits<T>::has_denorm == std::denorm_present) && ((std::numeric_limits<T>::min)() / 2 != 0))
{
test_value(z, name);
test_value(-z, name);
}
test_value(one, name);
test_value(-one, name);
test_value(two, name);
test_value(-two, name);
#if defined(TEST_SSE2)
if((_mm_getcsr() & (_MM_FLUSH_ZERO_ON | 0x40)) == 0)
{
#endif
if(std::numeric_limits<T>::is_specialized && (std::numeric_limits<T>::has_denorm == std::denorm_present) && ((std::numeric_limits<T>::min)() / 2 != 0))
{
test_value(std::numeric_limits<T>::denorm_min(), name);
test_value(-std::numeric_limits<T>::denorm_min(), name);
test_value(2 * std::numeric_limits<T>::denorm_min(), name);
test_value(-2 * std::numeric_limits<T>::denorm_min(), name);
}
#if defined(TEST_SSE2)
}
#endif
static const int primes[] = {
11, 13, 17, 19, 23, 29,
31, 37, 41, 43, 47, 53, 59, 61, 67, 71,
73, 79, 83, 89, 97, 101, 103, 107, 109, 113,
127, 131, 137, 139, 149, 151, 157, 163, 167, 173,
179, 181, 191, 193, 197, 199, 211, 223, 227, 229,
233, 239, 241, 251, 257, 263, 269, 271, 277, 281,
283, 293, 307, 311, 313, 317, 331, 337, 347, 349,
353, 359, 367, 373, 379, 383, 389, 397, 401, 409,
419, 421, 431, 433, 439, 443, 449, 457, 461, 463,
};
for(unsigned i = 0; i < sizeof(primes)/sizeof(primes[0]); ++i)
{
T v1 = val;
T v2 = val;
for(int j = 0; j < primes[i]; ++j)
{
v1 = boost::math::float_next(v1);
v2 = boost::math::float_prior(v2);
}
BOOST_CHECK_EQUAL(boost::math::float_distance(v1, val), -primes[i]);
BOOST_CHECK_EQUAL(boost::math::float_distance(v2, val), primes[i]);
BOOST_CHECK_EQUAL(boost::math::float_advance(val, primes[i]), v1);
BOOST_CHECK_EQUAL(boost::math::float_advance(val, -primes[i]), v2);
}
if(std::numeric_limits<T>::is_specialized && (std::numeric_limits<T>::has_infinity))
{
BOOST_CHECK_EQUAL(boost::math::float_prior(std::numeric_limits<T>::infinity()), (std::numeric_limits<T>::max)());
BOOST_CHECK_EQUAL(boost::math::float_next(-std::numeric_limits<T>::infinity()), -(std::numeric_limits<T>::max)());
BOOST_MATH_CHECK_THROW(boost::math::float_prior(-std::numeric_limits<T>::infinity()), std::domain_error);
BOOST_MATH_CHECK_THROW(boost::math::float_next(std::numeric_limits<T>::infinity()), std::domain_error);
if(boost::math::policies:: BOOST_MATH_OVERFLOW_ERROR_POLICY == boost::math::policies::throw_on_error)
{
BOOST_MATH_CHECK_THROW(boost::math::float_prior(-(std::numeric_limits<T>::max)()), std::overflow_error);
BOOST_MATH_CHECK_THROW(boost::math::float_next((std::numeric_limits<T>::max)()), std::overflow_error);
}
else
{
BOOST_CHECK_EQUAL(boost::math::float_prior(-(std::numeric_limits<T>::max)()), -std::numeric_limits<T>::infinity());
BOOST_CHECK_EQUAL(boost::math::float_next((std::numeric_limits<T>::max)()), std::numeric_limits<T>::infinity());
}
}
//
// We need to test float_distance over mulyiple orders of magnitude,
// the only way to get an accurate true result is to count the representations
// between the two end points, but we can only really do this for type float:
//
if (std::numeric_limits<T>::is_specialized && (std::numeric_limits<T>::digits < 30) && (std::numeric_limits<T>::radix == 2))
{
T left, right, dist, fresult;
boost::uintmax_t result;
left = static_cast<T>(0.1);
right = left * static_cast<T>(4.2);
dist = boost::math::float_distance(left, right);
// We have to use a wider integer type for the accurate count, since there
// aren't enough bits in T to get a true result if the values differ
// by more than a factor of 2:
result = 0;
for (; left != right; ++result, left = boost::math::float_next(left));
fresult = static_cast<T>(result);
BOOST_CHECK_EQUAL(fresult, dist);
left = static_cast<T>(-0.1);
right = left * static_cast<T>(4.2);
dist = boost::math::float_distance(right, left);
result = 0;
for (; left != right; ++result, left = boost::math::float_prior(left));
fresult = static_cast<T>(result);
BOOST_CHECK_EQUAL(fresult, dist);
left = static_cast<T>(-1.1) * (std::numeric_limits<T>::min)();
right = static_cast<T>(-4.1) * left;
dist = boost::math::float_distance(left, right);
result = 0;
for (; left != right; ++result, left = boost::math::float_next(left));
fresult = static_cast<T>(result);
BOOST_CHECK_EQUAL(fresult, dist);
}
}
BOOST_AUTO_TEST_CASE( test_main )
{
test_values(1.0f, "float");
test_values(1.0, "double");
#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
test_values(1.0L, "long double");
test_values(boost::math::concepts::real_concept(0), "real_concept");
#endif
//
// Test some multiprecision types:
//
test_values(boost::multiprecision::cpp_bin_float_quad(0), "cpp_bin_float_quad");
// This is way to slow to test routinely:
//test_values(boost::multiprecision::cpp_bin_float_single(0), "cpp_bin_float_single");
test_values(boost::multiprecision::cpp_bin_float_50(0), "cpp_bin_float_50");
#if defined(TEST_SSE2)
int mmx_flags = _mm_getcsr(); // We'll restore these later.
#ifdef _WIN32
// These tests fail pretty badly on Linux x64, especially with Intel-12.1
_MM_SET_FLUSH_ZERO_MODE(_MM_FLUSH_ZERO_ON);
std::cout << "Testing again with Flush-To-Zero set" << std::endl;
std::cout << "SSE2 control word is: " << std::hex << _mm_getcsr() << std::endl;
test_values(1.0f, "float");
test_values(1.0, "double");
_MM_SET_FLUSH_ZERO_MODE(_MM_FLUSH_ZERO_OFF);
#endif
BOOST_ASSERT((_mm_getcsr() & 0x40) == 0);
_mm_setcsr(_mm_getcsr() | 0x40);
std::cout << "Testing again with Denormals-Are-Zero set" << std::endl;
std::cout << "SSE2 control word is: " << std::hex << _mm_getcsr() << std::endl;
test_values(1.0f, "float");
test_values(1.0, "double");
// Restore the MMX flags:
_mm_setcsr(mmx_flags);
#endif
}