reverse

auto eve::reverse = detail::named_shuffle_1<reverse_t> {}

inlineconstexpr

Defined in Header

#include <eve/module/core.hpp>

As any named shuffle, allows to pass a group size, to treat multiple elements as one. Group size has to be 0 < G <= T::size()

template <simd_value T, std::ptrdiff_t G>
T reverse(T x, eve::fixed<G>);  // (1)
 
template <simd_value T>
T reverse(T x);  // (2)

Parameters

• x - simd_value to shuffle
• G - (optional) - number of elements to treat as one.

(2) calls (1) with G == 1; (1) reverses positions of adjacent groups of elements of size G

Return value

Return x where groups of contiguous G elements are reversed.

Example

#include <eve/module/core.hpp>
#include <tts/tts.hpp>
 
using w_t = eve::wide<std::uint32_t, eve::fixed<4>>;
 
int main()
{
  w_t x {0, 1, 2, 3};
 
  TTS_EXPECT( eve::all( w_t{3, 2, 1, 0} == eve::reverse(x)) );
  TTS_EXPECT( eve::all( w_t{3, 2, 1, 0} == eve::reverse(x, eve::lane<1>)) );
  TTS_EXPECT( eve::all( w_t{2, 3, 0, 1} == eve::reverse(x, eve::lane<2>)) );
 
  // lane<0> is not OK
  TTS_EXPECT( eve::all( w_t{0, 1, 2, 3} == eve::reverse(x, eve::lane<4>)) );
}