bit_select

auto eve::bit_select = functor<bit_select_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto bit_select((auto value auto  m, auto value x, auto value y) noexcept;
}

Parameters

• m: mask
• x, y: selection choices

Return value The value of the selected bits is returned.

• In a short way (omitting casting details to bring all bit sizes of the parameters equal), it means that the result is composed of the bits of x for which the corresponding bit of m is set and the bits of y for which the corresponding bit of m is unset.
• If x or y is an simd value, the type of the result has the element type of the common type of x and y and the maximum of the cardinals of m and this type, otherwise it is the type of x.

Example

// revision 2
#include <eve/module/core.hpp>
#include <iostream>
 
int main()
{
 
  eve::wide wl = {2, -3, 0,  1 << 10};
  eve::wide wi = {3, -2, 4,  2 };
  eve::wide wu = {0u, 1023u, 1u, ~0u << 8};
 
  std::cout << "<- wl                       = " << wl << "\n";
  std::cout << "<- wi                       = " << wi << "\n";
  std::cout << "<- wu                       = " << wu << "\n";
 
  std::cout << "-> bit_select(wl, wu, 0) = " << eve::bit_select(wl, wu, ~0u) << "\n";
  std::cout << "-> bit_select(wl, wi, 0) = " << eve::bit_select(wl, wi, -1) << "\n";
}