Integrated: 8279676: Dubious YMM register clearing in x86_64 arraycopy stubs

[Aleksey Shipilev]

On Mon, 10 Jan 2022 16:59:18 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> See discussion in the bug.
> 
> Additional testing, TR3970X (Zen 2, AVX2):
>  - [x] Linux x86_64 fastdebug `hotspot_compiler_arraycopy`
>  - [x] Linux x86_64 fastdebug `tier1`
>  - [x] Linux x86_64 fastdebug `tier2`
>  - [x] Linux x86_64 fastdebug `tier3`
> 
> Additional testing, i5-11500 (Rocket Lake, AVX-512):
>  - [x] Linux x86_64 fastdebug `hotspot_compiler_arraycopy`
>  - [x] Linux x86_64 fastdebug `tier1`
>  - [x] Linux x86_64 fastdebug `tier2`
>  - [x] Linux x86_64 fastdebug `tier3`
> 
> Targeted arraycopy microbenchmarks find a barely noticeable improvement on TR 3970X and i5-11500 with UseAVX=2.

This pull request has now been integrated.

Changeset: 525b20fc
Author:    Aleksey Shipilev <shade at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/525b20fce0acd393f31fd37fe1f05f9d32577f77
Stats:     10 lines in 1 file changed: 0 ins; 10 del; 0 mod

8279676: Dubious YMM register clearing in x86_64 arraycopy stubs

Reviewed-by: kvn, vlivanov, neliasso

-------------

PR: https://git.openjdk.java.net/jdk/pull/7016