Landing: 5c9e3073ea91
Project / Subsystem
gcc / gcc/rs6000/vsx
Date
2026-08-07
Author
Michael Meissner
Commit
5c9e3073ea912bb799adcb1ce7785a233ee337be
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/rs6000/vsx
- patch_id
- —
- commit_hash
- 5c9e3073ea912bb799adcb1ce7785a233ee337be
- source_type
- github
- headline
- Optimize splat of V2DF/V2DI extract
- tldr
- GCC now optimizes the 'splat' operation on extracted elements from V2DF and V2DI vectors for PowerPC.
- author
- Michael Meissner
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • powerpc
- • vector
- • rs6000
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-07T00:00:00.000Z
GCC has added an optimization for PowerPC (specifically VSX instructions) that improves the ‘splat’ operation when applied to an extracted element from a V2DI (two double-precision integers) or V2DF (two double-precision floats) vector. Previously, similar optimizations existed for other vector types but were missing for these double-word vector types. The new combiner instruction significantly reduces the generated code for such operations, as demonstrated by a comparison on Power9.