Function `_mm512_mask_popcnt_epi64`

#[target_feature(enable = "avx512vpopcntdq")]
pub const fn _mm512_mask_popcnt_epi64(src: __m512i, k: __mmask8, a: __m512i) -> __m512i

For each packed 64-bit integer maps the value to the number of logical 1 bits.

Uses the writemask in k - elements are copied from src if the corresponding mask bit is not set. Otherwise the computation result is written into the result.

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