RFR: 8266252: Streamline AbstractInterpreter::method_kind

[Claes Redestad]

On Tue, 4 May 2021 01:44:08 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> This patch refactors AbstractInterpreter::method_kind to reduce branches on average while better compartmentalizing the exceptional cases.
>> 
>> Additionally Method::is_empty_method is trivial enough that making it inlineable helps reduce cost while reducing size of the libjvm.
>> 
>> Result is a 40% speed-up, or a reduction of .25% of instructions on Hello World that scales to larger applications.
>
> src/hotspot/share/interpreter/abstractInterpreter.cpp line 143:
> 
>> 141:       // _dsqrt will be selected for both Math::sqrt and StrictMath::sqrt, but the latter
>> 142:       // is native. Keep treating it like a native method in the interpreter
>> 143:       case vmIntrinsics::_dsqrt: return m->is_native() ? native : java_lang_math_sqrt;
> 
> Maybe we should add an assert that m must be one of the two methods mentioned by the above comment?

Ok. I'll add an assertion that allows for the StrictMath variant to be re-implemented in java

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PR: https://git.openjdk.java.net/jdk/pull/3798