Landing: 9cf7c3266406
Project / Subsystem
gcc / vect
Date
2026-08-06
Author
Kyrylo Tkachov
Commit
9cf7c3266406e909891d2a40aeb468a091ccdaf2
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- vect
- patch_id
- —
- commit_hash
- 9cf7c3266406e909891d2a40aeb468a091ccdaf2
- source_type
- github
- headline
- Recognize high-part multiply for types lacking vector forms.
- tldr
- Enables vectorization of high-part multiplies for types without direct vector representations.
- author
- Kyrylo Tkachov
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • vectorization
- • optimization
- • AArch64
- • SVE
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-06T00:00:00.000Z
This change enhances the vectorization pass to recognize high-part multiply operations even when the widened type (e.g., 128-bit result of a 64-bit multiply) does not have a direct vector form on the target architecture. Previously, the pattern matching would fail in such cases, preventing vectorization. Now, the pattern matching continues even without a vector type for the output, allowing the cast to be recognized and the over-widening machinery to handle it, thus enabling scalar code using these operations to be vectorized.