Landing: 325646488a30
Project / Subsystem
gcc / builtins
Date
2026-09-22
Author
Jakub Jelinek
Commit
325646488a306c36c28e84260b4dd551bd30a47f
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- builtins
- patch_id
- —
- commit_hash
- 325646488a306c36c28e84260b4dd551bd30a47f
- source_type
- github
- headline
- Fix fallback for atomic builtins when operands are memory
- tldr
- Ensures atomic operations correctly handle memory operands by forcing them into registers, preventing data races.
- author
- Jakub Jelinek
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • builtins
- • atomics
- • bugfix
- • threading
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-22T00:00:00.000Z
This commit fixes a bug where atomic builtins could incorrectly expand operands into memory locations, leading to potential data races. The expand_builtin_atomic_fetch_op and expand_ifn_atomic_bit_test_and functions now ensure that memory operands are first forced into a pseudo-register before the atomic operation is performed. This improves the reliability of atomic operations when operands might otherwise be subject to modification during expansion.