Function _mm256_permutex2var_epi8 

pub fn _mm256_permutex2var_epi8(a: __m256i, idx: __m256i, b: __m256i) -> __m256i

Available on x86-64 and target feature avx512vbmi and target feature avx512vl only.

Shuffle 8-bit integers in a and b across lanes using the corresponding selector and index in idx, and store the results in dst.

Intel’s documentation