avx-512f has four new compare instructions. like their xop counterparts they use the immediate field to select between 8 different comparisons. unlike their xop inspiration, however, they save the result to a mask register and initially only support doubleword and quadword comparisons. the avx-512bw extension provides the byte and word versions. note that two mask registers may be specified for the instructions, one to write to and one to declare regular masking.