Intel explicitly states which instructions sets each processor supports. They don’t list every random register or instruction. Those are captured in the detail

Intel explicitly states which instructions sets each processor supports. They don’t list every random register or instruction. Those are captured in the detailed documents. e.g. https://www.intel.com/content/www/us/en/products/sku/226066/intel-core-i712650h-processor-24m-cache-up-to-4-70-ghz/specifications.html https://www.intel.com/content/www/us/en/products/sku/226066/...