various DCE-related bugfixes (replaces #36888) #37147
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
Phi nodes are optimized away when there is only one predecessor, but this can cause problems in dead loops because forward references can be created, leading to issues with optimization passes that look at all code, dead or not. This fixes issue #29107 when DCE is turned on.
…ot counted This fixes #29253, which was caused by `simple_dce!` erroneously erasing SSA values that did not appear to be used, because these uses were only discovered in `just_fixup!` at the end of iterating over an `IncrementalCompact`.
PR #36684 changes `iterate(IncrementalCompact)` to return an extra index, but leaves its arguments unchanged. However, the PR decremented the index argument in a particular recursive call to `iterate`. This caused `iterate` not to recognise that it was done when `allow_cfg_transforms` was turned on.
vchuravy
force-pushed
the
yhls/bugfixes
branch
from
b210f8e
to
af4cf31
Compare
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Outdated suggestions cannot be applied.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.
Replaces #36888 and addresses the review comment there.