RFR: 8319716: RISC-V: Add SHA-2 [v2]

[Robbin Ehn]

On Mon, 13 Nov 2023 13:47:26 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

>> I think that's what RISC-V profiles are for [1] which make some basic extensions mandatory for each profile. And we already have JVM options like `UseRVA20U64` and `UseRVA22U64` for riscv. But there are still some optional extensions for each profile, say RVV for RVA22U64. So instead of feeding a rather long march to the JVM, I feel it's more reasonable to have some JVM options at the extension level (instead of sub-extension level) as suggested by @robehn.
>> 
>> Personally, I would suggest something slightly different. Say:
>>  "-XX:VectorCryptoExt=zvknhb", "-XX:VectorCryptoExt=zvknhb_zvkb", or "-XX:VectorCryptoExt=all"
>> 
>> This way we will still be able to distinguish specific sub-extensions while keeping one JVM option for each extension/collection.
>> 
>> [1] https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc
>
> Let's take it on the list:
> https://mail.openjdk.org/pipermail/riscv-port-dev/2023-November/001211.html

Yes, flags are messy. Please add new comments in the update.

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PR Review Comment: https://git.openjdk.org/jdk/pull/16562#discussion_r1407828712