is it possible to have defn compile to zig?

[ityonemo]

gut feeling says yes. Even if we can't have a jitting zig compiler until E-xyza/zigler#245, I think fusing operations should be reasonable to do, and at least it will cut out the (potentially expensive) process of marshalling and unmarshalling your tensors from erlang resources.

[ityonemo]

this may be a requirement to implement certain things, like reduce.

[elbow-jason]

I have never worked inside the Zig compiler so I don't know how viable this idea is, but you might be able to map Nx.Defn.Expr graph to Zig AST? This might be way more complicated than I am imagining though.

Most of the binary ops and unary ops that I looked at are already represented in Zig AST Tags: https://github.com/ziglang/zig/blob/68e7726478f89ca27127e68b79112c12ac7415f7/lib/std/zig/ast.zig#L410-L550

[ityonemo]

I think... We wouldn't want to convert to zig AST. I think we would want to create a secondary module and defdelegate the functions to the secondary module that implement zig code in ~Z blocks that can be textually generated from the defn contents.

What I know less about is if defn explicitly expects to be able to do runtime JIT compilation. If that's the case then it wouldn't be possible currently until this is figured out: E-xyza/zigler#245

There are a few open questions: Currently, in Ez, the tensor data are bound to a BEAM "resource". Zigler expects all functions dealing with a single resource to be contained by module boundary. I don't know yet how (or if) you can use resources between modules, so there might need to be some metadata exploration by Zigler to set this up correctly.

I just created this issue: E-xyza/zigler#251