RFR: 8278947: Support for array constants in constant table [v2]

[Jatin Bhateja]

On Tue, 4 Jan 2022 08:47:52 GMT, Quan Anh Mai <duke at openjdk.java.net> wrote:

>> Hi,
>> 
>> This patch adds support for arrays in compiled code constant tables and uses it for various vector replicate operations on x86.
>> 
>> Test: GHA, linux x64 tier 1-3
>> 
>> Thank you very much.
>
> Quan Anh Mai 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 10 additional commits since the last revision:
> 
>  - Merge branch 'master' into constantVectorUpdate
>  - update copyright
>  - missing type in array_constant
>  - Merge branch 'master' into constantVector
>  - use constant table for remaining types
>  - Merge branch 'master' into constantVector
>  - refactor
>  - replicate using constant
>  - Merge branch 'master' into constantVector
>  - initial commit

Hi @merykitty ,

This could be used to optimize some vector APIs like Vector.iota if all its inputs are constant by directly dumping the resultant constant array.

Another use could be to bring contents of the some constant generating stubs near to native method, but that may need detailed performance analysis since it may improve iCache hits but may increase over all code size which may impact the in-lining behavior.

Best Regards

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PR: https://git.openjdk.java.net/jdk/pull/6908