Function _mm256_mask_alignr_epi8

#[target_feature(enable = "avx512bw", enable = "avx512vl")]
pub const fn _mm256_mask_alignr_epi8(src: __m256i, k: __mmask32, a: __m256i, b: __m256i, IMM8: i32) -> __m256i

Concatenate pairs of 16-byte blocks in a and b into a 32-byte temporary result, shift the result right by imm8 bytes, and store the low 16 bytes in dst using writemask k (elements are copied from src when the corresponding mask bit is not set).

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