MultiDefPrunedLiveness: add support for arbitrary uses/defs. #64926
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
This was recently introduced as a result of rebasing commits. It never did anything useful on the main branch.
PrunedLiveness only knows about the live blocks and uses. The PrunedLiveRange subclass is now responsible for updating liveness based on both the defs and uses. This is in preparation for handling non-SSA liveness when uses occur before the first def.
This now supports liveness holes within blocks where previously we expected a phi def. PrunedLiveness is streamlined for SSA liveness where we expect the defs and uses to be related in the SSA def-use graph. MultiDefPrunedLiveness was added on top of SSAPrunedLivenes to handle extended SSA liveness that occurs with phis, but are still connected in the def-use graph. Recently MultiDefPrunedLiveness was repurposed for liveness of addressible storage. This means that we can now have uses before defs in the same block without a corresponding phi. Fortunately, handling this case is a straightforward extension of MultiDefPrunedLiveness that does not complicate or penalize the streamlined SSA case.
|
preset=buildbot_incremental,tools=RA,stdlib=RA |
|
@swift-ci test |
|
@swift-ci benchmark |
|
@swift-ci test source compatibility |
|
Building with the incremental preset failed in a SwiftPM test unrelated to this change: |
|
Source compat suite fails to build Doggie on main in SILGen. No new failures here. |
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Outdated suggestions cannot be applied.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.
This now supports liveness holes within blocks where previously we
expected a phi def.
PrunedLiveness is streamlined for SSA liveness where we expect the
defs and uses to be related in the SSA def-use graph.
MultiDefPrunedLiveness was added on top of SSAPrunedLivenes to handle
extended SSA liveness that occurs with phis, but are still connected
in the def-use graph. Recently MultiDefPrunedLiveness was repurposed
for liveness of addressible storage. This means that we can now have
uses before defs in the same block without a corresponding phi.
Fortunately, handling this case is a straightforward extension of
MultiDefPrunedLiveness that does not complicate or penalize the
streamlined SSA case.
Restores PR: MultiDefPrunedLiveness: add support for arbitrary uses/defs. #64625
The CI failure in watchos RemoveWhere.o appears unrelated:
rdar://107341949 (Swift CI: [main, armv7k] benchmark/O-armv7k-apple-watchos2.0/RemoveWhere.o: assert in Control Flow Optimizer)