RFR: 8342884: RISC-V: verify float <--> float16 conversion [v2]

[Ludovic Henry]

On Thu, 24 Oct 2024 09:12:52 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> Hi,
>> Can you help to review this simple patch? it removes the `Experimental` of the `UseZvfh`.
>> Thanks
>> 
>> Currently, only float <--> float16 conversions use Zvfh extension, I've run the jmh tests on bananapi, the performance result shows it's good.
>> <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-XX:+UseZfh -XX:+UnlockExperimentalVMOptions -XX:+/-UseZvfh | (size) | Mode | Cnt | Score -intrinsic | Score +intrinsic | Error | Units | Improvement
>> -- | -- | -- | -- | -- | -- | -- | -- | --
>> Fp16ConversionBenchmark.float16ToFloat | 2048 | avgt | 10 | 8129.72 | 4729.125 | 71.937 | ns/op | 1.719
>> Fp16ConversionBenchmark.float16ToFloatMemory | 2048 | avgt | 10 | 16.9 | 16.894 | 0.002 | ns/op | 1
>> Fp16ConversionBenchmark.floatToFloat16 | 2048 | avgt | 10 | 12561.962 | 3767.944 | 12.652 | ns/op | 3.334
>> Fp16ConversionBenchmark.floatToFloat16Memory | 2048 | avgt | 10 | 18.146 | 18.147 | 0.003 | ns/op | 1
>> 
>> </google-sheets-html-origin>
>
> Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:
> 
>   hw probe

Marked as reviewed by luhenry (Committer).

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PR Review: https://git.openjdk.org/jdk/pull/21664#pullrequestreview-2393853909