pub unsafe fn _mm256_cmp_epu64_mask(
    a: __m256i, 
    b: __m256i, 
    const IMM3: _MM_CMPINT_ENUM
) -> __mmask8Available on x86-64 and target feature 
avx512f,avx512vl only.Expand description
Compare packed unsigned 64-bit integers in a and b based on the comparison operand specified by imm8, and store the results in mask vector k.