Landing: 656bb1d9e963
Project / Subsystem
gcc / gcc/match.pd
Date
2026-08-11
Author
Daniel Barboza
Commit
656bb1d9e9637028f917310e6c7688a0f1e99758
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/match.pd
- patch_id
- —
- commit_hash
- 656bb1d9e9637028f917310e6c7688a0f1e99758
- source_type
- github
- headline
- Simplify conditional bitwise OR patterns involving bitmasks.
- tldr
- Compiler patterns now simplify more conditional bitwise OR operations.
- author
- Daniel Barboza
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • pattern matching
- • bitwise operations
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-11T00:00:00.000Z
This commit expands the match.pd patterns to unconditionally simplify more conditional bitwise OR operations. It introduces new patterns to handle cases where a bit is checked and then set if not present, or where a bitmask is tested against itself. These simplifications apply when the bit is derived from a left shift (e.g., 1 << val) or when a full bitmask is involved, allowing the compiler to replace conditional logic with direct bitwise OR operations, thereby improving code efficiency.