RFR: 8322174: RISC-V: C2 VectorizedHashCode RVV Version [v19]

[Yuri Gaevsky]

On Wed, 6 Aug 2025 14:10:29 GMT, Yuri Gaevsky <duke at openjdk.org> wrote:

>> The patch adds possibility to use RVV instructions for faster vectorizedHashCode calculations on RVV v1.0.0 capable hardware.
>> 
>> Testing: hotspot/jtreg/compiler/ under QEMU-8.1 with RVV v1.0.0.
>
> Yuri Gaevsky has updated the pull request incrementally with one additional commit since the last revision:
> 
>   try m8 for grouping.

`223e0a3`:

--- -XX:+UseRVV ---
Benchmark            (size)  Mode  Cnt     Score    Error  Units
ArraysHashCode.ints       1  avgt   30    11.289 ±  0.017  ns/op
ArraysHashCode.ints       5  avgt   30    21.295 ±  0.003  ns/op
ArraysHashCode.ints      10  avgt   30    33.885 ±  0.051  ns/op
ArraysHashCode.ints      20  avgt   30    58.866 ±  0.007  ns/op
ArraysHashCode.ints      30  avgt   30    84.259 ±  0.120  ns/op
ArraysHashCode.ints      40  avgt   30    65.178 ±  0.043  ns/op
ArraysHashCode.ints      50  avgt   30    92.872 ±  0.170  ns/op
ArraysHashCode.ints      60  avgt   30   116.742 ±  0.684  ns/op
ArraysHashCode.ints      70  avgt   30    71.224 ±  0.225  ns/op
ArraysHashCode.ints      80  avgt   30    95.184 ±  0.603  ns/op
ArraysHashCode.ints      90  avgt   30   120.781 ±  0.079  ns/op
ArraysHashCode.ints     100  avgt   30    72.659 ±  0.032  ns/op
ArraysHashCode.ints     200  avgt   30   108.988 ±  0.036  ns/op
ArraysHashCode.ints     300  avgt   30   150.753 ±  2.586  ns/op
ArraysHashCode.ints    1000  avgt   30   330.159 ±  0.658  ns/op
ArraysHashCode.ints   10000  avgt   30  5555.054 ± 45.951  ns/op

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

PR Comment: https://git.openjdk.org/jdk/pull/17413#issuecomment-3160555632