EnzymeExt ignores runtime activity

[ptiede]

In Enzyme 0.13 runtime activity is now enabled in the ReverseMode type explicitly. For instance with ADtypes it would be done with

OptimizationFunction(f, AutoEnzyme(;mode=set_runtime_activity(Reverse)))

However, this isn't being respected in OptimizationEnzymeExt where Reverse and Forward are hardcoded.
For example

OptimizationBase.jl/ext/OptimizationEnzymeExt.jl

Lines 98 to 113 in 1ebca6f

	if g == true && f.grad === nothing
	function grad(res, θ, p = p)
	Enzyme.make_zero!(res)
	Enzyme.autodiff(Enzyme.Reverse,
	Const(firstapply),
	Active,
	Const(f.f),
	Enzyme.Duplicated(θ, res),
	Const(p)
	)
	end
	elseif g == true
	grad = (G, θ, p = p) -> f.grad(G, θ, p)
	else
	grad = nothing
	end

forces Enzyme.Reverse regardless of the passed mode.

[Vaibhavdixit02]

@gdalle how should this be accessed with SecondOrder, is so_adtype.inner.mode and so_adtype.outer.mode the recommended way?

[gdalle]

DifferentiationInterface makes the functions inner and outer public, but without exporting them. So if you have backend = SecondOrder(AutoEnzyme(; mode=Forward), AutoEnzyme(; mode=Reverse)) then you can do inner(backend).mode.
Note that inner and outer will function as the identity on any AbstractADType that is not a SecondOrder.

[Vaibhavdixit02]

That makes sense, I just needed to confirm

[gdalle]

Always a better idea to use documented accessors instead of private internals ;) wink wink SparseMatrixColorings