Description

Sacul0457

opened on Mar 21, 2026

Issue body actions

Bug report

Bug description:

A function version may be modified midway in the trace, so we need to recheck and add a watcher in the first check.
(All credits go to @Fidget-Spinner for pointing this out, #145080 (comment))

Ken Jin suggested to restore the old optimization instead as the fix above the will result in quite bad performance, as it’s calling it on every function deallocation.
The PR will also include a tiny bugfix found in _Py_uop_sym_set_func_version

Will open a PR soon

CPython versions tested on:

3.15, CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-146261: Fix bug in _Py_uop_sym_set_func_version #146291
• gh-146261: JIT: protect against function version changes #146300

Activity

1. Sacul0457

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Mar 21, 2026
2. picnixz

   added

   interpreter-core(Objects, Python, Grammar, and Parser dirs)(Objects, Python, Grammar, and Parser dirs)

   topic-JIT

   on Mar 21, 2026
3. Sacul0457

   changed the title [-]JIT: Function version is not re-checked in the optimizer for `_CHECK_FUNCTION_VERSION`[/-] [+]JIT: Restore previous optimization for `_CHECK_FUNCTION_VERSION`[/+] on Mar 22, 2026
4. Fidget-Spinner

   changed the title [-]JIT: Restore previous optimization for `_CHECK_FUNCTION_VERSION`[/-] [+]JIT: Optimization in `_CHECK_FUNCTION_VERSION` is wrong[/+] on Mar 22, 2026
5. Fidget-Spinner

   added a commit that references this issue on Mar 22, 2026

   gh-146261: Fix bug in `_Py_uop_sym_set_func_version` (GH-146291)

   1ceb1fb
6. CuriousLearner

   added a commit that references this issue on Mar 23, 2026

   Merge branch 'main' of github.com:python/cpython into fix-pythongh-13…

   3e05fa3
7. Fidget-Spinner

   added a commit that references this issue on Apr 12, 2026

   gh-146261: JIT: protect against function version changes (#146300)

   6f7bb29
8. prakashsellathurai

   added a commit that references this issue on Apr 13, 2026

   Revert "pythongh-146261: JIT: protect against function version changes (

   54f801c
9. StanFromIreland commented on Apr 19, 2026

   

   StanFromIreland

   on Apr 19, 2026

   Member

   More actions

   Triage: Can this be closed?
10. StanFromIreland

    added

    pendingThe issue will be closed if no feedback is providedThe issue will be closed if no feedback is provided

    on Apr 19, 2026
11. Fidget-Spinner

    closed this as completedon Apr 19, 2026
12. ljfp

    added 2 commits that reference this issue on Apr 25, 2026

    pythongh-146261: Fix bug in `_Py_uop_sym_set_func_version` (pythonGH-…

    76c5f26

    pythongh-146261: JIT: protect against function version changes (pytho…

    2fc06a4

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