gh-119786: Add jit.md. Move adaptive.md to a section of interpreter.md. #127175
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iritkatriel
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Nov 22, 2024
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iritkatriel
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- Issue: create an internals documentation folder in the cpython repo #119786
iritkatriel
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A lot of the terminology here is confusing, as we haven't put a lot of effort into choosing good names.
I'd suggest using "interpreter" for tier 1 including the specializations and "jit" for tier 2.
This leads to some odd terminology like "jit interpreter" for the tier 2 interpreter, but I think it is clearer overall.
I think a lot of core devs and the wider community think that what we currently call the "jit", i.e. the machine code generation pass, is where the performance gains will come from, but they will come from all of tier 2. The earlier passes will be vital for good performance.
Also, maybe add a diagram like this: faster-cpython/ideas#557 (comment)
InternalDocs/tier2.md
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| # The Tier 2 Interpreter | |||
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This is potentially confusing. The tier 2 interpreter is, in my mind, only used to debug tier 2 code. It is the jit-compiled machine code that executes tier 2 normally.
Also, I think we want to move away from "tier 2" and use "JIT". See faster-cpython/ideas#614 (comment)
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I'm making this change, but the code does refer to tier 2 in various places so I think it needs to be mentioned, otherwise future devs will be confused.
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When you're done making the requested changes, leave the comment: |
iritkatriel
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I have made the requested changes; please review again. |
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Thanks for making the requested changes! @markshannon, @mdboom: please review the changes made to this pull request. |
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| ### Maintaining stats | ||
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| Finally, take care that stats are gathered correctly. |
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If we currently have docs about pystats, we may want to link to that here. (If we don't, don't worry about that now...)
| and a `_PyUOpExecutor_Type` is created to contain it. | ||
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| ## Debugging a uop executor in the JIT interpreter | ||
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Can you add a sentence or two saying why we have this strange looking interpreter?
Being able to debug and analyze the optimizations prior independent of machine code generation is vey valuable.
Co-authored-by: Mark Shannon <[email protected]>
Co-authored-by: Mark Shannon <[email protected]>
