Function _mm_maskz_cvtusepi16_epi8 

pub fn _mm_maskz_cvtusepi16_epi8(k: __mmask8, a: __m128i) -> __m128i

Available on x86-64 and target feature avx512bw and target feature avx512vl only.

Convert packed unsigned 16-bit integers in a to packed unsigned 8-bit integers with unsigned saturation, and store the results in dst using zeromask k (elements are zeroed out when the corresponding mask bit is not set).

Intel’s documentation