fix: completeness issue in cycle scalar constructor from bigfield #19475
+15
−3
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
suyash67
approved these changes
Jan 12, 2026
Contributor
suyash67
left a comment
suyash67
left a comment
There was a problem hiding this comment.
Looks good. Nice catch!
ledwards2225
merged commit 65f4d0a
into
merge-train/barretenberg
12 of 13 checks passed
github-merge-queue bot
pushed a commit
that referenced
this pull request
Jan 14, 2026
BEGIN_COMMIT_OVERRIDE chore: Improve Chonk debug info (#19538) chore: translator non-native and decomp relations audit (#19081) chore: add safety to derive_generators and tweak pedersen scope (#19525) fix: ci-barretenberg-full mode fixes (#19466) test: use WASM backend for bbjs-test acir tests (#19529) fix: use absolute path in run_test.sh for CI fix: use env_objects in bb-external library fix: completeness issue in cycle scalar constructor from bigfield (#19475) chore: review a few minor files for ultra/mega audit (#19513) END_COMMIT_OVERRIDE
github-actions bot
pushed a commit
that referenced
this pull request
Jan 14, 2026
…9475) In the constructor of a cycle_scalar from a bigfield element, limb1 is split across the lo and hi slices of the scalar. If the max value of limb1 is such that the limb fits entirely in the lo slice, calling `no_wrap_split_at` would result in an assertion failure (i.e. `BB_ASSERT(lsb_index < num_bits);`). This PR introduces handling for this edge case by checking this condition first then setting the hi slice contribution of limb1 to 0 if needed.
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Outdated suggestions cannot be applied.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.
In the constructor of a cycle_scalar from a bigfield element, limb1 is split across the lo and hi slices of the scalar. If the max value of limb1 is such that the limb fits entirely in the lo slice, calling
no_wrap_split_atwould result in an assertion failure (i.e.BB_ASSERT(lsb_index < num_bits);). This PR introduces handling for this edge case by checking this condition first then setting the hi slice contribution of limb1 to 0 if needed.