static inline __m128i enc_reshuffle (__m128i in) { // Input, bytes MSB to LSB: // 0 0 0 0 l k j i h g f e d c b a in = _mm_shuffle_epi8(in, _mm_set_epi8( 10, 11, 9, 10, 7, 8, 6, 7, 4, 5, 3, 4, 1, 2, 0, 1)); // in, bytes MSB to LSB: // k l j k // h i g h // e f d e // b c a b const __m128i t0 = _mm_and_si128(in, _mm_set1_epi32(0x0FC0FC00)); // bits, upper case are most significant bits, lower case are least significant bits // 0000kkkk LL000000 JJJJJJ00 00000000 // 0000hhhh II000000 GGGGGG00 00000000 // 0000eeee FF000000 DDDDDD00 00000000 // 0000bbbb CC000000 AAAAAA00 00000000 const __m128i t1 = _mm_mulhi_epu16(t0, _mm_set1_epi32(0x04000040)); // 00000000 00kkkkLL 00000000 00JJJJJJ // 00000000 00hhhhII 00000000 00GGGGGG // 00000000 00eeeeFF 00000000 00DDDDDD // 00000000 00bbbbCC 00000000 00AAAAAA const __m128i t2 = _mm_and_si128(in, _mm_set1_epi32(0x003F03F0)); // 00000000 00llllll 000000jj KKKK0000 // 00000000 00iiiiii 000000gg HHHH0000 // 00000000 00ffffff 000000dd EEEE0000 // 00000000 00cccccc 000000aa BBBB0000 const __m128i t3 = _mm_mullo_epi16(t2, _mm_set1_epi32(0x01000010)); // 00llllll 00000000 00jjKKKK 00000000 // 00iiiiii 00000000 00ggHHHH 00000000 // 00ffffff 00000000 00ddEEEE 00000000 // 00cccccc 00000000 00aaBBBB 00000000 return _mm_or_si128(t1, t3); // 00llllll 00kkkkLL 00jjKKKK 00JJJJJJ // 00iiiiii 00hhhhII 00ggHHHH 00GGGGGG // 00ffffff 00eeeeFF 00ddEEEE 00DDDDDD // 00cccccc 00bbbbCC 00aaBBBB 00AAAAAA }