Landing: 33cd7bbb32c5
Project / Subsystem
gcc / match
Date
2026-05-21
Author
Avinal Kumar
Commit
33cd7bbb32c5eee4aff7aa06f351aa983be419bc
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- match
- patch_id
- —
- commit_hash
- 33cd7bbb32c5eee4aff7aa06f351aa983be419bc
- source_type
- github
- headline
- GCC now handles `X != INT_MIN ? -X : INT_MIN` without bailing out.
- tldr
- GCC optimizes a conditional negation involving `INT_MIN` by using an unsigned negation to avoid undefined behavior.
- author
- Avinal Kumar
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • gcc
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-05-21T00:00:00.000Z
GCC can now optimize expressions of the form X != INT_MIN ? -X : INT_MIN even when the signed negation of INT_MIN is undefined behavior. The compiler now emits an unsigned negate (equivalent to (signed)(-(unsigned)X)) in these cases, mirroring the existing handling of the abs pattern for the same edge case. This ensures the expression is well-defined and allows for further optimization.