Landing: 9acbae69609a
Project / Subsystem
gcc / middle-end
Date
2026-07-26
Author
Kyrylo Tkachov
Commit
9acbae69609a41df0f20db6222842414a85067ea
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- middle-end
- patch_id
- —
- commit_hash
- 9acbae69609a41df0f20db6222842414a85067ea
- source_type
- github
- headline
- middle-end: Look through VEC_DUPLICATE_EXPR in ssa_uniform_vector_p
- tldr
- Improves `ssa_uniform_vector_p` to correctly handle `VEC_DUPLICATE_EXPR` in GIMPLE form.
- author
- Kyrylo Tkachov
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • middle-end
- • optimization
- • aarch64
- • simd
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-07-26T00:00:00.000Z
The ssa_uniform_vector_p function, which identifies the element a uniform vector is a splat from, has been updated to correctly handle VEC_DUPLICATE_EXPR in its GIMPLE form. Previously, it only handled the bare tree form. This oversight caused callers, such as the lowpart-to-highpart NEON builtin fold on aarch64, to miss optimizations. The change ensures that splatted vectors created using VEC_DUPLICATE_EXPR in GIMPLE assignments are recognized, restoring expected code generation and optimization for vector operations.