pub unsafe fn _mm256_mask_shldi_epi64(
    src: __m256i, 
    k: __mmask8, 
    a: __m256i, 
    b: __m256i, 
    const IMM8: i32
) -> __m256iThis is supported on x86 and target feature 
avx512vbmi2,avx512vl only.Expand description
Concatenate packed 64-bit integers in a and b producing an intermediate 128-bit result. Shift the result left by imm8 bits, and store the upper 64-bits in dst using writemask k (elements are copied from src when the corresponding mask bit is not set).