Landing: 50be38676af8
Project / Subsystem
gcc / aarch64
Date
2026-09-15
Author
Naveen
Commit
50be38676af8ed32744b856ad6864302f7b400bc
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- aarch64
- patch_id
- —
- commit_hash
- 50be38676af8ed32744b856ad6864302f7b400bc
- source_type
- github
- headline
- Use UDOT for V8QI sad when dot product is available
- tldr
- Uses the UDOT instruction for V8QI SAD on targets with dot product support, improving performance.
- author
- Naveen
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • aarch64
- • optimization
- • SIMD
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-15T00:00:00.000Z
This commit enables the use of the UDOT instruction for calculating the absolute difference (SAD) of 8-byte vectors (V8QI) on AArch64 targets that support dot products. The SAD can now be lowered into two instructions: UABD/SABD to compute lane-wise differences, followed by a UDOT instruction. This UDOT effectively accumulates the results from the eight byte lanes into a V2SI vector, leveraging the dot product hardware for better performance.