RFR: 8334474: RISC-V: verify perf of ExpandBits/CompressBits (rvv) [v2]

[Hamlin Li]

> Hi, 
> Can you help to review the patch?
> It removes the previous added intrinsic for Long/Integer.expand/compress, as on several real hardware, I observe obvious performance regression.
> 
> Thanks
> 
> ## Performance
> Tests on bananapi, for other platform, please check jbs issue for test data.
> 
> ### Before
> data
> <google-sheets-html-origin style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;">
> Benchmark - keep intrinsic | (maxNumbits) | (size) | Mode | Cnt | Score | Error | Units
> -- | -- | -- | -- | -- | -- | -- | --
> o.o.b.j.lang.Integers.compress | N/A | 500 | avgt | 10 | 11710.439 | 17.936 | ns/op
> o.o.b.j.lang.Integers.expand | N/A | 500 | avgt | 10 | 14878.742 | 23.472 | ns/op
> o.o.b.j.lang.Longs.compress | N/A | 500 | avgt | 10 | 24555.06 | 2.632 | ns/op
> o.o.b.j.lang.Longs.expand | N/A | 500 | avgt | 10 | 35827.714 | 25.022 | ns/op
> 
> </google-sheets-html-origin>
> 
> 
> ### After
> data
> <google-sheets-html-origin style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;">
> Benchmark - remove intrinsic | (maxNumbits) | (size) | Mode | Cnt | Score | Error | Units
> -- | -- | -- | -- | -- | -- | -- | --
> o.o.b.j.lang.Integers.compress | N/A | 500 | avgt | 10 | 9294.835 | 1.459 | ns/op
> o.o.b.j.lang.Integers.expand | N/A | 500 | avgt | 10 | 5749.835 | 0.945 | ns/op
> o.o.b.j.lang.Longs.compress | N/A | 500 | avgt | 10 | 4735.15 | 1.082 | ns/op
> o.o.b.j.lang.Longs.expand | N/A | 500 | avgt | 10 | 5668.552 | 2.168 | ns/op
> 
> </google-sheets-html-origin>

Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:

  fix test typo

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22102/files
  - new: https://git.openjdk.org/jdk/pull/22102/files/8cd4e1e9..d1546433

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22102&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22102&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22102.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22102/head:pull/22102

PR: https://git.openjdk.org/jdk/pull/22102