Vector35 / Vector35/binaryninja-api
Simplify `sbb` ternary pattern
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- Dominant language
- C++
- Stars
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- Forks
- 298
- Avg merge
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- Merged PRs (30d)
- 19
Description
The following pattern:
a = sbb(x, x, y != 0) & -4
Can be simplified down to:
if (y != 0)
a = -4
else
a = 0
Example: sparkle giraffe juggling toaster.zip @ 1c00013a0
Seen @ 1c00013a0 as
a = (sbb(x, x, y != 0) & -4) + 5
notice the additional + 5 at the end. Most likely we'd need to take that into account too and do the whole simplification in one step. So the output becomes
if (y != 0)
a = 1
else
a = 5
Compare with other tools here: https://dogbolt.org/?id=eed48ff1-8c4b-4a5d-8fc8-abc82a21b1fe#BinaryNinja=215&Hex-Rays=523
Contributor guide
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First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the pattern from commit 1c00013a0, including the added +5 case, and inspect how the decompiler currently handles sbb(x, x, y != 0) & -4. Compare the result with Binary Ninja and Hex-Rays using the linked Dogbolt example. Done means the output becomes a conditional with 1 and 5 for the full expression, rather than simplifying only the masked subexpression.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- cpp
- Domain
- reverse-engineering
- Issue type
- Feature
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100