Function _ktestc_mask64_u8 

pub fn _ktestc_mask64_u8(a: __mmask64, b: __mmask64) -> u8

Available on x86 and target feature avx512bw only.

Compute the bitwise NOT of 64-bit mask a and then AND with 8-bit mask b, if the result is all zeros, store 1 in dst, otherwise store 0 in dst.

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