RFR: 8300197: Freeze/thaw an interpreter frame using a single copy_to_chunk() call [v3]

[Fredrik Bredberg]

On Wed, 26 Apr 2023 14:46:00 GMT, Fredrik Bredberg <duke at openjdk.org> wrote:

>> On certain architectures (like AARCH64) padding may be inserted between the locals and the rest of the stack frame in order to keep the frame pointer 16-byte-aligned.
>> 
>> This padding is currently not freezed, instead freezing of a single interpreter stack frame is done using two separate copy_to_chunk() calls (see recurse_freeze_interpreted_frame). Likewise, thawing is done using two separate copy_from_chunk() calls.
>> 
>> This poses a bit of a problem when trying to relativize stack addresses in interpreter frames ([JDK-8289296](https://bugs.openjdk.org/browse/JDK-8289296)). Since relative offsets may need to be changed during freezing and thawing.
>> 
>> By both freezing and thawing the padding we remove the need to change any relative offsets in runtime.
>> 
>> Tested tier1-tier8 on supported platforms, found no new issues. PowerPC and RISC-V was sanity tested using Qemu.
>
> Fredrik Bredberg has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:
> 
>  - Put back assert in recurse_thaw_interpreted_frame
>  - Merge branch 'master' into freeze_thaw_interpreter_JDK-8300197_2023-01-19
>  - Updated after review
>  - 8300197: Freeze/thaw an interpreter frame using a single copy_to_chunk() call

Thanks for the review guys. Can any of you give me a helping hand (sponsor) the integration.

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PR Comment: https://git.openjdk.org/jdk/pull/13477#issuecomment-1531040842