Landing: 93352420faab

Project / Subsystem

gcc / lra

Date

2026-07-18

Author

Matt Turner

Commit

93352420faab917cc4b6fcf1127b9242fc9d25b0

Source

github

Perf win

No

Breaking

No

All attributes

project
gcc
subsystem
lra
patch_id
commit_hash
93352420faab917cc4b6fcf1127b9242fc9d25b0
source_type
github
headline
LRA now correctly marks frame pointer live when needed.
tldr
Fixed LRA to mark the frame pointer as live when it's determined to be necessary, preventing miscompiles.
author
Matt Turner
outcome
committed
performance_win
false
breaking_change
false
series_id
series_parts
[]
tags
  • lra
  • bugfix
  • alpha
discussion_id_link
bugzilla_pr
date
2026-07-18T00:00:00.000Z

This commit resolves a bug where the Late Register Allocator (LRA) might fail to mark the frame pointer as live, even when it was determined to be needed. This omission could lead to miscompilations on certain architectures like Alpha, where the frame pointer’s role in stack frame setup and restoration is critical. The fix ensures that LRA consistently treats the frame pointer as live in such scenarios, aligning its behavior with the IRA (Instruction Register Allocator) pass.