The reason for undecidability of halting is that a program's state may grow without bound. If a program's memory usage is bounded, its halting can be determined

The reason for undecidability of halting is that a program's state may grow without bound. If a program's memory usage is bounded, its halting can be determined. So the computer is not like a Turing machine since its programs don't use Turing machine's key feature - infinite tape. Although the naive way of deciding halting requires exponential time in program's memory bound, AGIs will speed that up for many programs by using clever math.