pub unsafe fn _mm_permutex2var_epi64(
    a: __m128i,
    idx: __m128i,
    b: __m128i
) -> __m128i
🔬This is a nightly-only experimental API. (stdsimd #48556)
Available on (x86 or x86-64) and target feature avx512f,avx512vl and x86 only.
Expand description

Shuffle 64-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