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GH-144179: Use recorded values to make optimizer more robust#144437

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markshannon merged 3 commits intopython:mainfrom
markshannon:optimize-using-recorded-values-2
Feb 5, 2026
Merged

GH-144179: Use recorded values to make optimizer more robust#144437
markshannon merged 3 commits intopython:mainfrom
markshannon:optimize-using-recorded-values-2

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@markshannon markshannon commented Feb 3, 2026

  • Add three new symbol kinds
  • Do not smuggle code object in _PUSH_FRAME operand
  • Fix small bug in predicate analysis

* Add three new symbol kinds
* Do not smuggle code object in _PUSH_FRAME operand
* Fix small bug in predicate analysis
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You need tests for the new symbolic types in the optimizer_symbols.c as well.

tier2 op(_GUARD_CODE, (version/2 -- )) {
PyObject *code = PyStackRef_AsPyObjectBorrow(frame->f_executable);
EXIT_IF(code == Py_None);
EXIT_IF(((PyCodeObject *)code)->co_version != version);
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Why do we need this? Doesn't a _CHECK_VALIIDTY suffice?

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_CHECK_VALIDITY only checks if the executor is valid, not that we are executing the expected path.
We need to check that we have the expected code object.

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I don't remember: do we have code version watchers? if so they should work with _CHECK_VALIDITY right?

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Watchers only work if they've been wired up, which is the job of the optimizer, not the front-end.

sym->tag = JIT_SYM_RECORDED_VALUE_TAG;
sym->recorded_value.known_type = true;
sym->recorded_value.value = value;
}
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Why do we not set bottom here and for the one below?

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I presume you mean when sym->cls.type != Py_TYPE(value).
I'll add that.

@markshannon markshannon merged commit b53fc7c into python:main Feb 5, 2026
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encukou pushed a commit to encukou/cpython that referenced this pull request Feb 5, 2026
…ythonGH-144437)

* Add three new symbol kinds
* Do not smuggle code object in _PUSH_FRAME operand
* Fix small bug in predicate analysis
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2 participants