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. You can also use the ia32intrin.h header file for these intrinsics.

_mm_shuffle_epi8

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

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];
 }
}