Function _mm_alignr_epi64

pub fn _mm_alignr_epi64(a: __m128i, b: __m128i, const IMM8: i32) -> __m128i

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

Concatenate a and b into a 32-byte immediate result, shift the result right by imm8 64-bit elements, and store the low 16 bytes (2 elements) in dst.

Only lowest bit is used from the mask (shift at maximum by 8 bytes)!

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