Landing: b4de9d73b479
Project / Subsystem
gcc / tree-optimization
Date
2026-10-05
Author
Richard Biener
Commit
b4de9d73b47972bc89df288997c8f3a3862bc1b1
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- tree-optimization
- patch_id
- —
- commit_hash
- b4de9d73b47972bc89df288997c8f3a3862bc1b1
- source_type
- github
- headline
- FRE optimization improved by fixing aliasing walk logic
- tldr
- Fixes a bug in alias analysis that caused incorrect handling of PHI nodes, enabling more effective loop-invariant code motion.
- author
- Richard Biener
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • loop optimization
- • alias analysis
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-10-05T00:00:00.000Z
This commit addresses an issue in GCC’s alias analysis that prevented loop-invariant code motion (LICM) from being applied effectively in certain loop scenarios. The problem occurred when translating aliased uses, causing the get_continuation_for_phi function to fail. By clearing the visited bitmap during translation and removing an unnecessary abort_on_visited flag, the analysis can now correctly traverse complex control flow, enabling more FRE optimizations.