We saw algorithms designing circuits that no human engineer would design, even before the LLM (using genetic algorithms). So out-the-box thinking can be also more reachable than this author thinks.
But there's a reason we don't use those algorithms. We don't need out-of-the-box thinking that's so far outside the box that it's useless.
With these kinds of circuits, they were so sensitive to the specific conditions that the circuit was tested in (temperature, process variation, ..) that the solution couldn't be generalized to be used outside of that specific experiment.
We need the kind of intelligence that can question what assumptions can be challenged, and which we need to keep to have a viable (eventually commercially viable) solution.
If that was the case, then the algorithm was useless or flawed. IRL autorouters must take into account real physical constraints, lie wire length, signal integrity and tolerances to produce valid designs. A circuit that doesn't perform well under IRL conditions violates those constraints.
including, IIRC, at least one FPGA-based circuit that had a blob of logic not connected to anything else (ie could not possibly be involved in the logical functioning of the circuit), but when removed the implementation stopped working. So the actual circuit wasn't a sensible design option, just a very implementation-specific local minimum.
I think the original design challenge was something like a tone discriminator circuit. I can't recall the details
Yes, another case like this in which stray capacitance/inductances between traces was optimized in making an effective FPGA. Initial the developers had no idea why it worked so well. They found it to be exceedingly temperature sensitive. That clue gave them the answer.
