flags = _mm_unpackhi_epi32(descs[0], descs[1]);
tmp_desc = _mm_unpackhi_epi32(descs[2], descs[3]);
tmp_desc = _mm_unpacklo_epi64(flags, tmp_desc);
flags = _mm_unpackhi_epi32(descs[0], descs[1]);
tmp_desc = _mm_unpackhi_epi32(descs[2], descs[3]);
tmp_desc = _mm_unpacklo_epi64(flags, tmp_desc);