signgam

auto eve::signgam = functor<signgam_t>

inlineconstexpr

Header file

#include <eve/module/special.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto signgam(floating_value auto x)                          noexcept; // 1
 
   // Lanes masking
   constexpr auto signgam[conditional_expr auto c](floating_value auto x) noexcept; // 2
   constexpr auto signgam[logical_value auto m](floating_value auto x)    noexcept; // 2
}

Parameters

• x: floating value.
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.

Return value

1. The value of eve::sign(eve::tgamma(x)) is returned (without computing eve::tgamma(x));
2. The operation is performed conditionnaly.

External references

• C++ standard reference: tgamma
• Wikipedia: Gamma function
• Wolfram MathWorld: Gamma Function
• DLMF: gamma function

Example

// revision 1
#include <eve/module/special.hpp>
#include <iostream>
 
int main()
{
  eve::wide wf{0.5f, -1.5f, -1.0f, 1.0f, -2.5f,
               eve::inf(eve::as<float>()), eve::minf(eve::as<float>()), eve::nan(eve::as<float>())};
 
  std::cout << "<- wf                         = " << wf << "\n";
 
  std::cout << "-> signgam(wf)                = " << eve::signgam(wf) << "\n";
  std::cout << "-> signgam[ignore_last(2)](wf)= " << eve::signgam[eve::ignore_last(2)](wf) << "\n";
  std::cout << "-> signgam[wf != -1.5f](wf)   = " << eve::signgam[wf != -1.5f](wf) << "\n";
}