Landing: 9e391103a9fc
Project / Subsystem
gcc / gcc
Date
2026-07-30
Author
Aldy Hernandez
Commit
9e391103a9fcc140584193ca7f75e5e64181d632
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc
- patch_id
- —
- commit_hash
- 9e391103a9fcc140584193ca7f75e5e64181d632
- source_type
- github
- headline
- Enable sub-ranges for frange optimization.
- tldr
- GCC's frange optimization now supports two sub-ranges, improving range representation and enabling new optimizations.
- author
- Aldy Hernandez
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • gcc
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-07-30T00:00:00.000Z
GCC’s frange optimization pass has been enhanced to support two sub-ranges, up from one. This change allows for better representation of inequalities such as non-zero values, which were previously missed. With two sub-ranges, the optimization now captures 99.63% of ranges encountered in a Fortran corpus, significantly closing the gap with internal tables used by DOM. This improvement is expected to fix several open PRs related to nonzero folding and signed zero optimizations, while also yielding modest gains in jump threading and constant propagation opportunities.