[mypyc] Use generator helper fast path on resume - #21954
Merged
Merged
Conversation
Extend the direct helper fast path for statically known native generators and coroutines to resumes after suspension. This avoids generic send dispatch and StopIteration handling on completion. The savings compound in deep native coroutine chains, where each await frame would otherwise pay this overhead.
p-sawicki
approved these changes
Sep 7, 2026
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Extend the direct helper method fast path for statically known native
generators and coroutines to resumes after suspension. This avoids
generic send dispatch and StopIteration handling on completion.
The savings compound in deep native coroutine chains, where each
await frame would otherwise pay this overhead.
In an (unrealistic) microbenchmark this made a long await chain
1.8x faster. With event loop overhead included and an
asyncio.sleep(0),call, the improvement in modified microbenchmark was about 10%
when using uvloop.
I used coding agent assist.