High-Level Export API

[GregoryComer]

🚀 The feature, motivation and pitch

Currently, export and lowering requires the user to make many decisions about delegates and quantization, which require the user to have a deeper understanding of the domain and stack. It would be desirable to provide a higher-level export API that handles the majority of the most common use cases, especially for mobile.

Ideally, this API should have the following characteristics:

• Provide out-of-box support / recipes for the most common backend and quantization patterns. That might be things like Mobile CPU with 8-bit static quantization, Mobile CPU with 4-bit quantization, CoreML, Mobile GPU, etc.
• Power users should be able to easily understand what each recipes is doing from looking at the code. This allows them to use them as a starting point for more advanced use cases. Maybe each recipe has a dedicated .py file.
• Use naming that the user understands (Mobile CPU or CPU vs XNNPACK), though we want to include enough information to learn more. For example, we can provide a Mobile CPU target, but in the description, we mention that it uses the XNNPACK backend.
• It should be first-class and under the executorch namespace and repository. It should be called something that indicates that it is a "core" or "core-adjacent" ET API. Getting Started docs should focus on this high-level API, where possible, with enough information to guide power users to the lower-level APIs.
• Available targets/recipes should represent well-supported paths for ET usage and should work out-of-box. We can use this to help guide the user to things (backends, quant schemes, etc.) that are well supported.

Alternatives

No response

Additional context

No response

RFC (Optional)

No response

cc @mergennachin @byjlw

[mergennachin]

For reference @tarun292 's iterating on this doc: https://docs.google.com/document/d/1Pu842srYychecGACqlRy8k94-pjYhOmaG1mPVcWairU/edit?tab=t.0

[Gasoonjia]

Also @tarun292 has summarized the design and put into ExecuTorch discussion: #9027