Landing: 94082ac189cf
Project / Subsystem
gcc / x86
Date
2026-04-14
Author
H.J. Lu
Commit
94082ac189cf318ea4ad52ffdf9fa5f941ebcf9e
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- x86
- patch_id
- —
- commit_hash
- 94082ac189cf318ea4ad52ffdf9fa5f941ebcf9e
- source_type
- github
- headline
- Implement TARGET_FNTYPE_ABI to avoid callee-saved register spills
- tldr
- x86 now uses TARGET_FNTYPE_ABI to prevent unnecessary spills of callee-saved registers when calling functions with no_caller_saved_registers.
- author
- H.J. Lu
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • x86
- • abi
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-04-14T00:00:00.000Z
This commit introduces the TARGET_FNTYPE_ABI mechanism for x86, preventing unnecessary spills of callee-saved registers when calling functions marked with no_caller_saved_registers. This change refactors call expansion logic, removing explicit ABI-switching clobbers and correctly handling TLS calls and function ABIs, improving code generation efficiency and correctness.