I am trying to write a command line tool app which will be able to use 128 bit float type calculation. The only hint how to increase precision from available 80 bits to desired 128 bits I found in the net is using boost library. I found and installed boost library via mac port install tool, and compiled the following sample code:
#include <boost/multiprecision/float128.hpp>
#include <boost/math/special_functions/gamma.hpp>
#include <iostream>
int main()
{
using namespace boost::multiprecision;
// Operations at 128-bit precision and full numeric_limits support:
float128 b = 2;
// There are 113-bits of precision:
std::cout << std::numeric_limits<float128>::digits << std::endl;
// Or 34 decimal places:
std::cout << std::numeric_limits<float128>::digits10 << std::endl;
// We can use any C++ std lib function, lets print all the digits as well:
std::cout << std::setprecision(std::numeric_limits<float128>::max_digits10)
<< log(b) << std::endl;
// We can also use any function from Boost.Math:
std::cout << boost::math::tgamma(b) << std::endl;
// And since we have an extended exponent range we can generate some really large
// numbers here (4.02387260077093773543702433923004111e+2564):
std::cout << boost::math::tgamma(float128(1000)) << std::endl;
//
// We can declare constants using GCC or Intel's native types, and the Q suffix,
// these can be declared constexpr if required:
constexpr float128 pi = 3.1415926535897932384626433832795028841971693993751058Q;
return 0;
}
I got a buid error:
/opt/local/include/boost/multiprecision/float128.hpp:39:10: 'quadmath.h' file not found
The problem is caused by the following lines:
#if defined(BOOST_MP_USE_FLOAT128)
extern "C" {
#include <quadmath.h>
}
Is quadmath library & headers available under the xcode 7?
How can I get it?