40-year old dead architectures like Android on 64-bit ARM?[1] Pointer tagging isn't that rare, and as memory expands in practice I'd expect we might even end up

40-year old dead architectures like Android on 64-bit ARM?[1] Pointer tagging isn't that rare, and as memory expands in practice I'd expect we might even end up wanting >64-bit systems to allow for >48-bit real address spaces and/or >16-bit tags. The C standard means you don't have to care that there might actually be 2^8 NULL pointers since you're running on ARM with Top Byte Ignore in use. [1]https://source.android.com/devices/tech/debug/tagged-pointers https://source.android.com/devices/tech/debug/tagged-pointer...