Function _mm512_mask_expand_epi32 

pub fn _mm512_mask_expand_epi32(
    src: __m512i,
    k: __mmask16,
    a: __m512i,
) -> __m512i

Available on x86 and target feature avx512f only.

Load contiguous active 32-bit integers from a (those with their respective bit set in mask k), and store the results in dst using writemask k (elements are copied from src when the corresponding mask bit is not set).

Intel’s documentation