two_sqrt_approx

auto eve::two_sqrt_approx = functor<two_sqrt_approx_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   constexpr auto two_sqrt_approx(floating_value auto x) noexcept;
}

Parameters

• x: floating arguments.

Return value

Computes elementwise a pair of values [a,e] such that:

• a is eve::sqrt(x)
• e is a value such that a \(\oplus\)e is an approximation in doubled precision to \(\sqrt\)x, where \(\oplus\) (resp. \(\sqrt\)) adds (resp. take the square roots of) its parameters with infinite precision.

Example

// revision 1
#include <eve/module/core.hpp>
#include <iostream>
#include <iomanip>
 
int main()
{
  eve::wide wf0 = {3.0f, 2.5f, 32.7f, 1.0f};
 
  std::cout << "<- wf0                = " << wf0 << "\n";
 
  std::cout << "-> two_sqrt_approx(wf0) = " << eve::two_sqrt_approx(wf0) << "\n";
 
  auto [d, e] = eve::two_sqrt_approx(3.0f);
  std::cout << std::setprecision(15);
  std::cout << double(d) << " + " << double(e) << std::endl;
  std::cout << double(e)+double(d) << std::endl;
  std::cout << eve::sqrt(3.0) << std::endl;
  std::cout << eve::sqrt(3.0f) <<  std::endl;
  std::cout << eve::sqrt(3.0) - (double(e)+double(d))<< std::endl;
}