RFR: 8255617: Zero: purge the remaining bytecode interpreter profiling support [v2]

[Jie Fu]

On Tue, 3 Nov 2020 10:22:14 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> All the stubs in `interpreter/zero/bytecodeInterpreterProfiling.hpp` are empty. History shows the whole thing gradually moved to template interpreter. We can probably simplify Zero code by dropping these empty stubs altogether. Arguably, this makes porting to new architectures a bit harder, but it seems that the proper stepping stone after Zero is implementing template interpreter anyway.
>> 
>> On my TR 3970X, this improves:
>>  - Linux x86_64 Zero "make images" times from ~18 minutes to ~17.5 minutes
>> 
>> I would like to have the opinion of @GoeLin who added this for PPC64 porting back in 8u. And probably @DamonFool who is usually interested in Zero. And @jerboaa, @gnu-andrew who deal with Zero from time to time.
>
> Aleksey Shipilev 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 five additional commits since the last revision:
> 
>  - Merge branch 'master' into JDK-8255617-zero-purge-bi-profiliing
>  - Also remove now unused BytecodeInterpreter::mdx field
>  - Remove leftover variable
>  - Remove leftover comments
>  - 8255617: Zero: purge the remaining bytecode interpreter profiling support

Still looks good.

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Marked as reviewed by jiefu (Committer).

PR: https://git.openjdk.java.net/jdk/pull/944