RFR: 8357424: [JVMCI] Avoid incrementing decompilation count for hosted compiled nmethod [v7]

[Doug Simon]

On Fri, 13 Jun 2025 16:29:17 GMT, Yudi Zheng <yzheng at openjdk.org> wrote:

>> Hosted Truffle compilations are installed on the OptimizedCallTarget#profiledPERoot method. Any deoptimization contributes to its decompile count, which can easily exceed the PerMethodRecompilationCutoff threshold, permanently preventing highest tier compilation on this method. This PR exempts hosted compilations from this cutoff by ensuring their decompile count is not incremented for hosted compiled nmethods.
>
> Yudi Zheng 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 eight additional commits since the last revision:
> 
>  - Merge tag 'jdk-26+2' into JDK-8357424
>    
>    Added tag jdk-26+2 for changeset d7aa3498
>  - fix compilation error
>  - address comments
>  - Merge remote-tracking branch 'upstream/master' into JDK-8357424
>  - address comments
>  - address comments
>  - update copyright
>  - [JVMCI] Avoid incrementing decompilation count for hosted compiled nmethod

src/hotspot/share/code/nmethod.cpp line 1951:

> 1949:   // Could be gated by ProfileTraps, but do not bother...
> 1950: #if INCLUDE_JVMCI
> 1951:   if (is_jvmci_hosted()) {

Someone (like me!) is going to see this code a while from now and try remember why the decompilation count is not being decremented for JVMCI hosted nmethods. I think it's worth adding a comment.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25356#discussion_r2146084403