Of course, AVX-512 using 512-bit vector width can only compare-into-mask. This is fantastic for storing a bitmap, just vcmpps k1, zmm0, [rsi] / kmov [rdi], k1. But for storing a bool array, probably you'd want to kunpck to concatenate compare results, with 2x kunpckwd to combine 16-bit to 32-bit masks, then kunpckdq to make a single 64-bit mask from 64 float compare results. Then use that with a zero-masked vmovdqu8 zmm0k1z, zmm1 and store that to memory. (A memory destination only allows merge-masking, not zero-masking.)