[cfe-dev] why a switch statement for coroutine?

[Jim Hurd via cfe-dev]

The code generation for coroutine resume is pretty much the same as a
switch statement; for a few suspend points it generates if(state==x) goto
label else..., and for many suspend points it uses a jump table.

https://godbolt.org/g/U3d1sz

I would have guessed that it would save the resume state as a call address
directly, rather than save the state as an index into a jump table. What
advantage does the switch approach have? Why not just save a new resume
address in the frame prefix after each resume?
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