Optimize subtype checking by avoiding a nested function #14325
Merged
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
Mypyc isn't good at compiling nested functions, and this one was in one of the hottest code paths in all of mypy. The nested function wasn't even used all the time, but mypyc will still construct a closure object every time. This adds some code duplication, but it's well worth it. Amazingly, this speeds up self-check by about 10%! This addresses some of the slowdown introduced in #13303. #14324 addresses another related slowdown.
|
According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉 |
|
out of curiosity, why did you pick this verbose/redundant approach instead of the one taken in #14277 ? does mypyc dislike the approach I took there? |
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Outdated suggestions cannot be applied.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.
Mypyc isn't good at compiling nested functions, and this one was in one of the hottest code paths in all of mypy. The nested function wasn't even used that often, but mypyc would still construct a closure object every time.
This adds some code duplication, but it's well worth it. Amazingly, this speeds up self-check by about 10%, if my measurements are to be trusted!
This addresses some of the slowdown introduced in #13303. #14324 addresses another related slowdown.