RFR: 8329083: RISC-V: Update profiles supported on riscv

[Hamlin Li]

On Thu, 4 Apr 2024 08:05:45 GMT, Fei Yang <fyang at openjdk.org> wrote:

>> Hi,
>> Can you help to review this patch to update vm flags related to riscv profile?
>> Thanks
>> 
>> Currently there are vm options like -XX:+UseRVA20U64 and -XX:+UseRVA22U64 on riscv to indicate the supported riscv extension via profiles.
>> These profiles should be updated to reflect the full supported extensions and new profile like UseRVA23U64 should be added too.
>
> src/hotspot/cpu/riscv/vm_version_riscv.hpp line 191:
> 
>> 189:   #define RV_USE_RVA22U64                            \
>> 190:     RV_ENABLE_EXTENSION(UseRVC)                      \
>> 191:     RV_ENABLE_EXTENSION(UseRVV)                      \
> 
> Note that V was optional in RVA22U64.

In fact, when I worked on it, I'm bit confused what it should be? including optional or not.

Peviously, zfh is already enabled by the RVA22U64, but it's optional by [spec](https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc#613-rva22u64-optional-extensions), so I followed this pattern.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/18599#discussion_r1551284845