unpack3_epi32
z12 = unpack3_epi32(y0, y1, y2, y3);
z13 = unpack3_epi32(y4, y5, y6, y7);
z14 = unpack3_epi32(y8, y9, y10, y11);
z15 = unpack3_epi32(y12, y13, y14, y15);
z12 = unpack3_epi32(y0, y1, y2, y3);
z13 = unpack3_epi32(y4, y5, y6, y7);
z14 = unpack3_epi32(y8, y9, y10, y11);
z15 = unpack3_epi32(y12, y13, y14, y15);