gh-129695: Optimize _PyFloat_FromDouble_ConsumeInputs()
#129697
+43
−18
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Add optimization for ``_PyFloat_FromDouble_ConsumeInputs()`` for the free-threaded build. Implement free-threaded versions of ``_Py_DECREF_SPECIALIZED`` and ``_Py_DECREF_NO_DEALLOC`` as well.
These calls need to be be wrapped in Py_REF_DEBUG ifdefs.
colesbury
reviewed
Feb 6, 2025
| } | ||
|
|
||
| #else // Py_GIL_DISABLED | ||
|
|
||
| PyObject *_PyFloat_FromDouble_ConsumeInputs(_PyStackRef left, _PyStackRef right, double value) |
There was a problem hiding this comment.
I think we should inline this into the call sites, even at the cost of repeating code. I don't think the stackpointer manipulations will be correct otherwise. (cc @markshannon)
We should also use PyStackRef_CLOSE_SPECIALIZED instead of _Py_DECREF_SPECIALIZED. The same applies to _Py_DECREF_NO_DEALLOC, but I think that stackref variant will need to be added.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Add optimization for
_PyFloat_FromDouble_ConsumeInputs()for the free-threaded build. Implement free-threaded versions of_Py_DECREF_SPECIALIZEDand_Py_DECREF_NO_DEALLOCas well.pyperformance results vs merge base
Based on a microbenchmark I wrote, this seems to give a small speed up for binary operations on floats, it there are temporary results (refcnt == 1) that can be re-used. The
_Py_DECREF_SPECIALIZEDand_Py_DECREF_SPECIALIZEDchanges seem to help as well but only a little (hard to accurately measure).The longobject.c file also uses
_Py_DECREF_SPECIALIZEDand I guess that might be the reason the pidigits benchmark got faster. I not sure why the pyflate benchmark got slower. Perhaps due to_Py_DECREF_SPECIALIZEDtaking the slow path too often._PyFloat_FromDouble_ConsumeInputs#129695