My understanding is that AUIPC builds the destination address by adding a 32 bit offset to the current PC, i.e. it is relative, and that this works with both 32

My understanding is that AUIPC builds the destination address by adding a 32 bit offset to the current PC, i.e. it is relative, and that this works with both 32 and 64 bit addresses. The difference is that, on 32-bit systems this allows to immediately access any address while on 64-bit systems you are limited to this relative 32-bit window.