You can easily truncate or pad to convert between 64-32bit as long as the 64bit end stays in the lower 2GB. You could do everything else in userspace if you re

You can easily truncate or pad to convert between 64-32bit as long as the 64bit end stays in the lower 2GB. You could do everything else in userspace if you really wanted. At the cost of safety, type handling and optimization from the compiler as all it would see is 64bit pointers being typecast and generic 32bit numeric data. Whatever you were looking to gain would be lost in extra work, and you can forget about debugging. But theoretically...