Yes to the latter, kinda to the former. In reverse order: This file goes back several OS versions: https://github.com/apple/darwin-xnu/blob/master/osfmk/x86_

Yes to the latter, kinda to the former. In reverse order: This file goes back several OS versions: https://github.com/apple/darwin-xnu/blob/master/osfmk/x86_64/pmap_pcid.c https://github.com/apple/darwin-xnu/blob/master/osfmk/x86_64... sysctl machdep.cpu.features | grep PCID (cf. xnu/osfmk/i386/cpuid.[hc], ibid.)