The post glosses over it a bit - the CRC32X instruction always uses the common polynomial 0x04C11DB7 (matching zlib, commonly just called CRC-32), and there's a second instruction, CRC32CX, which is the same but uses the polynomial 0x1EDC6F41, known as CRC-32C (Castagnoli). The constants in the post are also for 0x04C11DB7, but the linked Intel article explains how to they can be calculated for arbitrary polynomials, so the faster method is also generic, which is nice.