Integrated: 8281467: Allow larger OptoLoopAlignment and CodeEntryAlignment

[Aleksey Shipilev]

On Tue, 8 Feb 2022 18:19:00 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> I am following up on the performance issue where the culprit seems to be the too low `OptoLoopAlignment`. To perform better experiments, I suggest allowing larger alignments.
> 
> Note that we cannot make `OptoLoopAlignment` larger than `CodeEntryAlignment`, because nmethod copy would break it, see assert in `MacroAssembler::align`. See [JDK-8273459](https://bugs.openjdk.java.net/browse/JDK-8273459) for latest discussion about it. So `CodeEntryAlignment` needs to be configurable as well.
> 
> The default values for options are different per platform, so tests are x86_64 specific.
> 
> No default value is changed, this only unblocks experiments.
> 
> Additional testing:
>  - [x] New tests on Linux x86_64 fastdebug
>  - [x] New tests on Linux x86_64 release

This pull request has now been integrated.

Changeset: b1564624
Author:    Aleksey Shipilev <shade at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/b1564624ce454d0df9b2464424b7b5e449481ee6
Stats:     178 lines in 4 files changed: 176 ins; 0 del; 2 mod

8281467: Allow larger OptoLoopAlignment and CodeEntryAlignment

Reviewed-by: kvn, dlong

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PR: https://git.openjdk.java.net/jdk/pull/7388