It should be noted that on most x86 machines, they only support 48-bit pointers, with 16 free bits you can use. I think some Intel chips have 57-bit support. B

It should be noted that on most x86 machines, they only support 48-bit pointers, with 16 free bits you can use. I think some Intel chips have 57-bit support. But no CPU actually reads all 64-bits for some reason. So yeah, you can shove count-bits, either 16 of them or 7 of them or so.