[masklinn]

> Duff is relying on the fact you're allowed to intermingle the switch block and the loop

That's just a special case of being able to intermingle switch with arbitrary syntax, which is what TFA does, before it jumps to computed gotos.

[doe_eyes]

The overarching point appears to be getting rid of angle brackets, which is not something that Duff is doing. Further, Duff's device keeps case labels on the left of its control structure; moving ifs to the left is the other "innovation" here.

I think you really have to squint your eyes to see the similarities, beyond the general theme of exploiting the counterintuitive properties of switch statements.