Shuffle Intrinsics

These Supplemental Streaming SIMD Extensions 3 (SSSE3) intrinsics are used to perform shuffle operations. The prototypes for these intrinsics are in tmmintrin.h.

To use these intrinsics, include the immintrin.h file as follows:

#include <immintrin.h>

_mm_shuffle_epi8

extern __m128i _mm_shuffle_epi8(__m128i a, __m128i b);

Shuffle bytes from a according to contents of b.

Interpreting a, b, and r as arrays of unsigned 8-bit integers:

for (i = 0; i < 16; i++){
 if (b[i] & 0x80){
  r[i] =  0;
 }
 else {
  r[i] = a[b[i] & 0x0F];
 }
}

_mm_shuffle_pi8

extern __m64 _mm_shuffle_pi8(__m64 a, __m64 b);

Shuffle bytes from a according to contents of b.

Interpreting a, b, and r as arrays of unsigned 8-bit integers:

for (i = 0; i < 8; i++){
 if (b[i] & 0x80){
  r[i] =  0;
 }
else {
 r[i] = a[b[i] & 0x07];
 }
}
Para obtener información más completa sobre las optimizaciones del compilador, consulte nuestro Aviso de optimización.