73ef4ff3
 Hu Chunming
提交三方库
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
///////////////////////////////////////////////////////////////////////////////
// Copyright 2016 John Maddock. Distributed under 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 <boost/multiprecision/cpp_bin_float.hpp>
int main()
{
typedef boost::multiprecision::number<boost::multiprecision::backends::cpp_bin_float<256> > ext_float_t;
typedef boost::multiprecision::number<boost::multiprecision::backends::cpp_bin_float<2046> > long_ext_float_t;
ext_float_t x = 5e15;
x += 0.5;
ext_float_t x1 = x + 255.0 / (1 << 20); // + 2^-12 - eps
ext_float_t x2 = x + 257.0 / (1 << 20); // + 2^-12 + eps
double d1 = x1.convert_to<double>();
double d2 = x2.convert_to<double>();
std::cout << std::setprecision(18) << d1 << std::endl;
std::cout << std::setprecision(18) << d2 << std::endl;
x = 1e7 + 0.5;
x1 = x + ldexp(255.0, -38); // + 2^-30 - eps
x2 = x + ldexp(257.0, -38); // + 2^-30 + eps
float f1 = x1.convert_to<float>();
float f2 = x2.convert_to<float>();
std::cout << std::setprecision(9) << f1 << std::endl;
std::cout << std::setprecision(9) << f2 << std::endl;
long_ext_float_t lf(1);
lf += std::numeric_limits<long_ext_float_t>::epsilon();
lf += std::numeric_limits<float>::epsilon() / 2;
BOOST_MP_ASSERT(lf != 1);
float f3 = lf.convert_to<float>();
std::cout << std::setprecision(9) << f3 << std::endl;
return (d1 == d2) && (f1 == f2) && (f3 != 1) ? 0 : 1;
}
|
