Feature or enhancement

Proposal:

I was looking at the IPA inlining dump as part of investigating the root cause of gh-132295 and noticed that we're inlining a number of slow path functions related to specialization, instrumentation, and error handling in the interpreter loop when performing LTO (full list here):

_Py_Specialize_CallKw
_Py_Specialize_CompareOp
_Py_Specialize_ContainsOp
_Py_Specialize_ForIter
_Py_Specialize_LoadGlobal
_Py_Specialize_LoadSuperAttr
_Py_Specialize_Send
_Py_Specialize_StoreAttr
_Py_Specialize_StoreSubscr
_Py_Specialize_ToBool
_Py_Specialize_UnpackSequence
_Py_call_instrumentation
_Py_call_instrumentation_instruction
_Py_call_instrumentation_line
get_exception_handler

I suspect these are being inlined because we use unit tests for collecting PGO data. These should be executed relatively infrequently for "normal" Python code. We should mark them as noinline.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-132336: Mark a few "slow path" functions used by the interpreter loop as noinline #132337
• gh-132336: Only mark slow path functions used by the interpreter loop as noinline in free-threaded builds #132424