[CopyPropagation] Eliminate redundant moves. #64339
Merged
Conversation
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
Extracted the predicate from inline in RedundantMoveValueElimination into the new function which can now be called from elsewhere (CopyPropagation).
No need for a worklist of any sort, a simple list suffices.
SemanticARCOpts already eliminates move values that are redundant that block its optimizations. But it's always run after CopyPropagation. Because move_values divide copy-extended lifetimes, move_values obstruct lifetime canonicalization. If a move_value isn't separating lifetimes with different characteristics (specifically: lexicallity, escaping), then it is only obstructing lifetime canonicalization. Remove it before canonicalizing the lifetime of the moved-from value.
nate-chandler
force-pushed
the
copy-propagation/redundant-move-elim
branch
from
45f1881 to
1621692
Compare
|
@swift-ci please test |
|
@swift-ci please test windows platform |
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Outdated suggestions cannot be applied.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.
SemanticARCOptsalready eliminatesmove_values that are redundant that block its optimizations. But it's always run afterCopyPropagation.Because
move_values divide copy-extended lifetimes, move_values obstruct lifetime canonicalization. If amove_valueisn't separating lifetimes with different characteristics (specifically: lexicallity, escaping), then it is only obstructing lifetime canonicalization. Remove it before canonicalizing the lifetime of the moved-from value.rdar://106834481