Landing: 956d39b165f9
Project / Subsystem
gcc / gcc
Date
2026-08-07
Author
Michael Meissner
Commit
956d39b165f95b842432ba9ca4f97d6474196fd5
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc
- patch_id
- —
- commit_hash
- 956d39b165f95b842432ba9ca4f97d6474196fd5
- source_type
- github
- headline
- Power10 VSX registers simplify zero extensions from memory.
- tldr
- New Power10 instructions simplify zero-extending memory values into VSX registers, reducing code size and improving efficiency.
- author
- Michael Meissner
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • powerpc
- • optimization
- • vector
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-07T00:00:00.000Z
GCC now leverages new Power10 instructions to simplify the process of zero-extending values from memory into VSX registers. Previously, this involved multiple steps, including extending to a general-purpose register pair and then moving to a VSX register. The new lxvrdx (and similar) instructions can directly load and zero-extend data into VSX registers, eliminating intermediate steps and resulting in more efficient code for operations involving __uint128_t.