Landing: 7b8104e346cf
Project / Subsystem
gcc / tree-ssa
Date
2026-09-05
Author
Kyrylo Tkachov
Commit
7b8104e346cf3949b0ca6eab93106ac860fb3306
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- tree-ssa
- patch_id
- —
- commit_hash
- 7b8104e346cf3949b0ca6eab93106ac860fb3306
- source_type
- github
- headline
- tree-ssa: Canonicalize arithmetic overflow IFN operands
- tldr
- Canonicalizes operands for arithmetic overflow internal functions to improve consistency.
- author
- Kyrylo Tkachov
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • compiler-internals
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-05T00:00:00.000Z
This change canonicalizes the operands of commutative arithmetic overflow internal functions, such as ADD_OVERFLOW. Previously, the order of operands could be non-canonical, potentially disagreeing with related addition operations. By using tree_swap_operands_p, the operands are now ordered consistently, improving the predictability of optimization passes and reducing potential discrepancies in generated code. This also applies to MUL_OVERFLOW, while SUB_OVERFLOW retains its original order as it is not commutative. A new test case for aarch64 verifies this behavior.