RFR: 8350086: Inline hot Method accessors for faster task selection [v3]

[Andrew Haley]

On Fri, 14 Feb 2025 15:12:50 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> These methods show up prominently on Leyden profiles, as compilation policy asks these properties for methods very often during compile task selection:
>>  - `Method::invocation_count`
>>  - `Method::backedge_count`
>>  - `Method::highest_comp_level`
>> 
>> We can move the definitions for these methods to method.inline.hpp to make them eligible for better inlining.
>> 
>> `interpreter_invocation_count()` method is a bit weird, looks like a leftover from [JDK-8251462](https://bugs.openjdk.org/browse/JDK-8251462). Removing it would prompt more cleanups and renamings in `ciMethod`, so I would leave it for future enhancement.
>> 
>> Additional testing: 
>>  - [x] Spot-checked Leyden profiles, methods are now fully inlined into hot `CompilerBroker` methods
>>  - [x] Ad-hoc Leyden benchmarks show minor improvements (< 1%) for time spent in compiler threads
>
> Aleksey Shipilev has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - One more include for Minimal VM
>  - Turn declarations proper inline

That's nice. It looks to me like those methods would only be a few instructions long, so the overhead of a subroutine would be disproportionate, and the cost of inlining small. Win-win.

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Marked as reviewed by aph (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23634#pullrequestreview-2618563348