Landing: c2ded18d4fcc
Project / Subsystem
gcc / gcc/phiprop
Date
2026-03-27
Author
Andrew Pinski
Commit
c2ded18d4fcc5d7d951a6bbc455dadbf5a837939
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/phiprop
- patch_id
- —
- commit_hash
- c2ded18d4fcc5d7d951a6bbc455dadbf5a837939
- source_type
- github
- headline
- Phirop: Move the VUSE check before dominator tests.
- tldr
- The VUSE check now happens before the dominator tests in the phiprop pass, which should result in a small optimization.
- author
- Andrew Pinski
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • compiler pass
- • SSA
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-03-27T00:00:00.000Z
The phiprop pass now performs the VUSE check before the dominator tests. This reordering avoids unnecessary dominator tests when the VUSE check would have failed, resulting in a small optimization. The dominator tests no longer indicate if a propagation can occur, so checks that prevent propagation should be performed first.