Generalize the select-collapse logic in the BDD simplification pass. - #4801
Merged
Conversation
copybara-service
Bot
force-pushed
the
test_965956443
branch
4 times, most recently
from
August 20, 2026 17:57
75449e6 to
f5d5174
Compare
This change adds the ability to collapse a chain of heterogeneous select nodes (composed of Select, PrioritySelect, and OneHotSelect) into a single OneHotSelect. This is achieved by generalizing the existing logic within the BDD simplification pass, which previously only collapsed chains of standard Select nodes. This change also extracts this transformation from the BDD simplification pass to its own pass. The new pass, called collapse select chains pass, is invoked towards the end of the optimization pipeline to avoid blocking the analyses that tend to be more accurate with simple select nodes. PiperOrigin-RevId: 967966663
copybara-service
Bot
force-pushed
the
test_965956443
branch
from
August 20, 2026 19:05
f5d5174 to
b5569e4
Compare
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
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Generalize the select-collapse logic in the BDD simplification pass.
This change adds the ability to collapse a chain of heterogeneous select nodes (composed of Select, PrioritySelect, and OneHotSelect) into a single OneHotSelect.
This is achieved by generalizing the existing logic within the BDD simplification pass, which previously only collapsed chains of standard Select nodes.
This change also extracts this transformation from the BDD simplification pass to its own pass.
The new pass, called collapse select chains pass, is invoked towards the end of the optimization pipeline to avoid blocking the analyses that tend to be more accurate with simple select nodes.