Ticket #12581: af_p4.cpp

#include <stdint.h>
#include <stdio.h>
#include <iostream>
#include <cmath>
#include <boost/multiprecision/cpp_bin_float.hpp>

typedef boost::multiprecision::number<boost::multiprecision::cpp_bin_float<128, boost::multiprecision::backends::digit_base_2> > boost_float128_t;

// static bool mine_is_better(const extfloat128_t a[2], const extfloat128_t& ra)
// {
  // if (a[0]==0 && a[1] < 0 && a[0].m_sign != 0 && ra==-1)
    // return true; // patch, boost returns +1, my answer is -1. Mine is better
  // if (isnan(a[1]) && isnan(ra))
    // return true; // patch, boost returns 0, my answer is nan. Mine is better
  // if (a[0]==0 && a[1]==0 && isnan(ra))
    // return true; // patch, boost returns 0, my answer is nan. Mine is better
  // return false;
// }

int main(int , char** )
{
  double tests[][2] = {
    {  HUGE_VAL, HUGE_VAL},
    { -HUGE_VAL, HUGE_VAL},
    {  HUGE_VAL,-HUGE_VAL},
    { -HUGE_VAL,-HUGE_VAL},
    { -0.0,     -1.0   },
    {  0.0,      nan("")},
    {  HUGE_VAL, nan("")},
    { -HUGE_VAL, nan("")},
  };
  for (int i = 0; i < 8; ++i) {
    double y = tests[i][0];
    double x = tests[i][1];
    double r = atan2(y, x);
    boost_float128_t by = y;
    boost_float128_t bx = x;
    boost_float128_t br = atan2(by, bx);
    std::cout << "C RTL atan2(" << y  << "," << x  << ") = " << r  << "\n";
    std::cout << "Boost atan2(" << by << "," << bx << ") = " << br << "\n";
  }
  return 0;
}