RFR: 8227369: pd_disjoint_words_atomic() needs to be atomic

[Erik Österlund]

On Tue, 22 Feb 2022 05:45:12 GMT, David Holmes <dholmes at openjdk.org> wrote:

> Replace the common "atomic" switch+loop code chunks in the pd code with a shared version that uses Atomic::load/store.
> 
> See details in the bug report that show how current code is actually replaced by `memcpy` (in some places at least) whereas the new code is not.
> 
> Platforms affected:
>  - all x86
>  - Zero
>  - Windows Aarch64
>  - PPC
> 
> Testing: tiers 1-3
> Additional builds: tiers 4 and 5
>  - builds covered: x86 and Zero
> 
> GHA
> - builds covered:  Windows-Aarch64
> 
> The only build affected and not tested is PPC. It would be great if someone could take this for a spin on PPC.
> 
> For platforms not affected by this change, i.e. those that already specialise the code, I make not claims regarding the atomicity or otherwise of those specialized versions. That would be for someone interested in those specific platforms to check out.
> 
> Thanks,
> David

Looks good, thanks for fixing this.

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

Marked as reviewed by eosterlund (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/7567