Landing: 73f32a2cbd8c
Project / Subsystem
gcc / lra
Date
2026-06-29
Author
Robin Dapp
Commit
73f32a2cbd8c3b910443448f8ab4a2d79e3ff520
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- lra
- patch_id
- —
- commit_hash
- 73f32a2cbd8c3b910443448f8ab4a2d79e3ff520
- source_type
- github
- headline
- lra: Pass INVALID_REGNUM to dependent filter.
- tldr
- Local Register Allocation (LRA) now passes an invalid register number to dependent filters when the reference operand is not yet determined.
- author
- Robin Dapp
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • lra
- • register allocation
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-06-29T00:00:00.000Z
This patch refines the Local Register Allocation (LRA) process by ensuring that dependent filters are properly invoked even when the reference operand’s register is not yet assigned. Previously, undefined reference operands led to filters being lenient, potentially causing early, incorrect register assignments that LRA could not fix later. The change allows filters to reject inputs more effectively in such scenarios and documents that INVALID_REGNUM can be passed to these filters.