RFR: 8297476: Increase InlineSmallCode default from 1000 to 2000 for RISC-V

[Fei Yang]

The current default value of InlineSmallCode on RISC-V is 1000. I witnessed notable performance improvement by increasing this value to 2000 when running the renaissance benchmark. Here are the exact commands used for each of the benchmarks:

Before:
$ java -XX:InlineSmallCode=1000 -XX:+UseParallelGC -Xms12g -Xmx12g -jar renaissance-gpl-0.14.1.jar -r 40 all

After:
$ java -XX:InlineSmallCode=2000 -XX:+UseParallelGC -Xms12g -Xmx12g -jar renaissance-gpl-0.14.1.jar -r 40 all

Best run time for one repetition (ms – lower is better) on Unmatched board:

Benchmark | Before | After | Ratio
-- | -- | -- | --
AkkaUct | 75629.766 | 71839.905 | 5.01%
Reactors | 98120.668 | 91597.120 | 6.65%
DecTree | 12144.666 | 11801.740 | 2.82%
Als | 57719.166 | 53307.041 | 7.64%
ChiSquare | 21704.666 | 16301.189 | 24.89%
GaussMix | 17494.891 | 17497.291 | -0.02%
LogRegression | 11881.352 | 11382.722 | 4.20%
MovieLens | 100944.374 | 96510.793 | 4.39%
NaiveBayes | 81946.569 | 68566.763 | 16.32%
PageRank | 43689.497 | 43204.553 | 1.11%
FjKmeans | 68398.667 | 67261.674 | 1.66%
FutureGenetic | 31752.695 | 31524.457 | 0.72%
Mnemonics | 126312.832 | 115335.512 | 8.69%
ParMnemonics | 93406.666 | 88320.443 | 5.45%
Scrabble | 6894.853 | 6888.426 | 0.09%
RxScrabble | 5163.473 | 4875.730 | 5.08%
Dotty | 14852.405 | 14667.255 | 1.25%
ScalaDoku | 95770.117 | 39728.637 | 58.52%
Philosophers | 13974.965 | 11579.551 | 17.14%
ScalaStmBench7 | 12185.093 | 12243.016 | -0.47%
FinagleChirper | 32676.065 | 30900.282 | 5.44%
FinagleHttp | 30633.640 | 30191.792 | 1.44%

Other testing: tier1-tier3 tested on Unmatched board.

I have also tested other possible values like 1500 and 2500, but the numbers say show 2000 would outperform those values in most of the cases. And I can verify no regressions across at least following benchmarks:

- Dacapo
- SPECjvm2008
- SPECjbb2005
- SPECjbb2015

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Commit messages:
 - 8297476: Increase InlineSmallCode default from 1000 to 2000 for RISC-V

Changes: https://git.openjdk.org/jdk/pull/11310/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11310&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8297476
  Stats: 6 lines in 1 file changed: 6 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/11310.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11310/head:pull/11310

PR: https://git.openjdk.org/jdk/pull/11310