RFR: 8293011: riscv: Duplicated stubs to interpreter for static calls

[Feilong Jiang]

On Mon, 29 Aug 2022 01:32:26 GMT, Dingli Zhang <duke at openjdk.org> wrote:

> Follow up [JDK-8280481](https://bugs.openjdk.org/browse/JDK-8280481), it provides duplicated stubs to interpreter for static calls.
> 
> ## Testing:
> 
> - hotspot/jdk tier1 on unmatched board
> - hotspot/jtreg/compiler/sharedstubs/SharedStubToInterpTest.java on qemu
> 
> 
> ## Results
> #### Results from [Renaissance 0.14.0](https://github.com/renaissance-benchmarks/renaissance/releases/tag/v0.14.0)
> Note: 'Nmethods with shared stubs' is the total number of nmethods counted during benchmark's run. 'Final # of nmethods' is a number of nmethods in CodeCache when JVM exited.
> 
> Because of the current hardware performance limitations, I selected a few cases to test and reduced the number of iterations using `-r 10`. The data is sufficient to reflect the effect of the optimization.
> 
> - riscv64
> 
> +------------------+-------------+----------------------------+---------------------+
> |    Benchmark     | Saved bytes | Nmethods with shared stubs | Final # of nmethods |
> +------------------+-------------+----------------------------+---------------------+
> | future-genetic   |       47824 |                       1278 |                1811 |
> | scrabble         |       30616 |                        738 |                1605 |
> | fj-kmeans        |       23320 |                        633 |                1386 |
> | par-mnemonics    |        2840 |                        621 |                1398 |
> | scala-kmeans     |       19544 |                        381 |                1365 |
> +------------------+-------------+----------------------------+---------------------+

Changes look good, except for one copyright issue.

src/hotspot/cpu/riscv/codeBuffer_riscv.cpp line 2:

> 1: /*
> 2:  * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.

Missing copyright of your company for the new file.

-------------

Changes requested by fjiang (Author).

PR: https://git.openjdk.org/jdk/pull/10057