Landing: 447618d27800
Project / Subsystem
gcc / out-of-ssa
Date
2026-07-26
Author
Kyrylo Tkachov
Commit
447618d278004c73797d4e579a02f721291072a6
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- out-of-ssa
- patch_id
- —
- commit_hash
- 447618d278004c73797d4e579a02f721291072a6
- source_type
- github
- headline
- out-of-SSA: Split partitions of parameters and results
- tldr
- out-of-SSA now splits partitions for parameters and results, fixing miscompilations on aarch64.
- author
- Kyrylo Tkachov
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • out-of-ssa
- • optimization
- • aarch64
- • memory-aliasing
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-07-26T00:00:00.000Z
The split_overlapping_partition_decls function in the out-of-SSA pass has been modified to also split partitions associated with PARM_DECL and RESULT_DECL. Previously, these were excluded, leading to incorrect code generation when parameters or results needed multiple memory partitions (e.g., incoming argument slot and a local slot). This fix addresses miscompilations observed on aarch64 at -Os by ensuring that distinct memory slots for parameters and results are correctly handled, preventing erroneous fusion of memory accesses.