byte_swap_adjacent

eve::byte_swap_adjacent = functor<byte_swap_adjacent_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
   // Regular overload
   constexpr auto byte_swap_adjacent(integral_value auto x, integral_value auto n)   noexcept; // 1
 
   // Lanes masking
   constexpr auto byte_swap_adjacent[conditional_expr auto c](integral_value auto x,
                                     integral_value auto n)                          noexcept; // 2
   constexpr auto byte_swap_adjacent[logical_value auto m](integral_value auto x,
                                     integral_value auto n)                          noexcept; // 2
}

Parameters

• x : argument.
• n : size of the groups of bytes to be swapped. Must be a power of 2 and less than the half size of the elements of x
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.

Return value

1. Return x with elementwise groups of N bytes swapped.
   • If N is greater to sizeof(x) 0 is returned.
   • If N is equal to sizeof(x) x is returned.
2. The operation is performed conditionnaly.

Note

Take care that eve::byte_swap_adjacent is NOT the EVE functional equivalent to std::byteswap. eve::byte_reverse IS. As the name does not say, std::byteswap reverse the order of the bytes which is not an adjacent swapping except for 16 bits words.

Example

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