pub unsafe fn _mm256_mask_blend_epi64(
    k: __mmask8,
    a: __m256i,
    b: __m256i
) -> __m256i
🔬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

Blend packed 64-bit integers from a and b using control mask k, and store the results in dst.

Intel’s documentation