countr_one

auto eve::countr_one = functor<countr_one_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

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

Parameters

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

Return value

1.The value of the number of consecutive 1 ("one") bits in the value of x, starting from the least significant bit ("right"), with same type as x, is returned.

1. The operation is performed conditionnaly.

External references

• C++ standard reference

Example

// revision 0
#include <eve/module/core.hpp>
#include <iostream>
 
int main()
{
  eve::wide wu0{0u, 1u, 2u, 3u, 4u, 5u, 6u, 7u};
 
  std::cout << "<- wu0                             = " << wu0 << "\n";
                                                   
  std::cout << "-> countr_one(wu0)                 = " << eve::countr_one(wu0) << "\n";
  std::cout << "-> countr_one[ignore_last(2)](wu0) = " << eve::countr_one[eve::ignore_last(2)](wu0) << "\n";
  std::cout << "-> countr_one[wu0 != 0](wu0)       = " << eve::countr_one[wu0 != 0](wu0) << "\n";
}