That’s a pretty important distinction. If someone in the 1800s invented a mechanical calculator that could do this operation in a single crank, I don’t think anyone would upset about that patent.

But then the patent would not be on the logic but the mechanical implementation. The obviousness would need to be judged on that basis. The method can be implemented using straightforward combinational logic so the single crank/cycle is a given after you have come up with the obvious method.

Back before software patents were a thing, the "math" was not patentable. Eliminating software patents will be a return to the previous status quo.

We have eliminated most software patents: see Alice Corp vs CLS bank.

The only thing this patent covers is the physical circuit implementation, not the math.

> The only thing this patent covers is the physical circuit implementation

The claims in that patent are not limited to a physical circuit implementation.

The description includes a circuit diagram as one possible embodiment of the claimed invention, but the patent covers any implementation (and the description indicates it was intended to cover instructions running on general purpose processors).

So the compiler developers had to pay fees? Or Intel and AMD?

If the compiler developers were developing their own circuits, yes.

But likely, Intel/AMD would have had to pay fees if they were implementing a similar solution in their hardware.