Merged
Conversation
The `pause` instruction doesn't have observable side effects, but for it to fulfill its purpose of making spinlocks more efficient, we need to avoid moving it out of loops. We previously did this by setting the `isAtomic` effect, but that effect will soon go away in favor of a more detailed analysis of how expressions may synchronize across threads. Switch to using `branchesOut` as the effect to keep `pause` from being moved instead and add a test demonstrating that it works as intended.
kripken
approved these changes
Feb 27, 2026
stevenfontanella
approved these changes
Feb 27, 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
3 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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
The
pauseinstruction doesn't have observable side effects, but for itto fulfill its purpose of making spinlocks more efficient, we need to
avoid moving it out of loops. We previously did this by setting the
isAtomiceffect, but that effect will soon go away in favor of a moredetailed analysis of how expressions may synchronize across threads.
Switch to using
branchesOutas the effect to keeppausefrom beingmoved instead and add a test demonstrating that it works as intended.