sign_alternate

eve::sign_alternate = functor<sign_alternate_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto sign_alternate(signed_value auto n)                          noexcept; // 1
 
   // Semantic options
   constexpr auto sign_alternate[downward](signed_value auto n)                noexcept; // 2
   constexpr auto sign_alternate[upward](signed_value auto n)                  noexcept; // 2
   constexpr auto sign_alternate[to_nearest](signed_value auto n)              noexcept; // 2
   constexpr auto sign_alternate[toward_zero](signed_value auto n)             noexcept; // 2
 
   // Lanes masking
   constexpr auto sign_alternate[conditional_expr auto c](signed_value auto n) noexcept; // 3
   constexpr auto sign_alternate[logical_value auto m](signed_value auto n)    noexcept; // 3
}

Parameters

• n : argument.
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.

Return value

1. elementwise \((-1)^\tilde n\) is returned, where \(\tilde n\) is the truncation of n.
2. The chosen rounding option is applyied to n before computation, instead of truncation.
3. The operation is performed conditionnaly.

Example

// revision 0
#include <eve/module/core.hpp>
#include <iostream>
 
int main()
{
  eve::wide wf0{0.0, 1.0, 2.0, 3.0, -1.0, -2.0, -3.0, -4.0};
  eve::wide wi0{0, 1, 2, 3, -1, -2, -3, -4};
 
  std::cout << "<- wf0                                 = " << wf0 << "\n";
  std::cout << "<- wi0                                 = " << wi0 << "\n";
                                                       
  std::cout << "-> sign_alternate(wf0)                 = " << eve::sign_alternate(wf0) << "\n";
  std::cout << "-> sign_alternate[ignore_last(2)](wf0) = " << eve::sign_alternate[eve::ignore_last(2)](wf0) << "\n";
  std::cout << "-> sign_alternate[wf0 != 0](wf0)       = " << eve::sign_alternate[wf0 != 0](wf0) << "\n";
  std::cout << "-> sign_alternate(wi0)                 = " << eve::sign_alternate(wi0) << "\n";
  std::cout << "-> sign_alternate[ignore_last(2)](wi0) = " << eve::sign_alternate[eve::ignore_last(2)](wi0) << "\n";
  std::cout << "-> sign_alternate[wi0 != 0](wi0)       = " << eve::sign_alternate[wi0 != 0](wi0) << "\n";
}