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

[Fei Yang]

On Thu, 14 Nov 2024 14:05:42 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> 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

Still good.

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

Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22102#pullrequestreview-2436396839