Landing: 3a4787033e4b
Project / Subsystem
gcc / tree-optimization
Date
2026-10-05
Author
Richard Biener
Commit
3a4787033e4b5dea2d1f7a6b30d4c85a00b7b91d
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- tree-optimization
- patch_id
- —
- commit_hash
- 3a4787033e4b5dea2d1f7a6b30d4c85a00b7b91d
- source_type
- github
- headline
- FRE optimization improved by avoiding duplicate PHI argument processing
- tldr
- Fixes a bug in FRE optimization where duplicate PHI arguments caused redundant work and potential failures in alias analysis.
- 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 is part of a fix for missed FRE optimizations in loops (PR127693). It addresses an issue where get_continuation_for_phi was called with duplicate PHI arguments when walking a backedge with a translated reference. By sorting PHI arguments and processing only unique ones, this patch avoids redundant work and prevents the abort_on_visited flag from tripping incorrectly, thereby enabling more FRE optimizations.