Function `_mm256_mask_alignr_epi64`

#[target_feature(enable = "avx512f", enable = "avx512vl")]
pub const fn _mm256_mask_alignr_epi64(src: __m256i, k: __mmask8, a: __m256i, b: __m256i, IMM8: i32) -> __m256i

Concatenate a and b into a 64-byte immediate result, shift the result right by imm8 64-bit elements, and store the low 32 bytes (4 elements) in dst using writemask k (elements are copied from src when the corresponding mask bit is not set).

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