Function _mm256_mask_blend_epi64 

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

Available on x86-64 and target feature avx512f and target feature avx512vl only.

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

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