RFR: 8351876: RISC-V: enable and fix some float round tests

[Hamlin Li]

On Thu, 13 Mar 2025 01:15:30 GMT, Fei Yang <fyang at openjdk.org> wrote:

>> Hi,
>> Can you help to review this simple patch?
>> It's a follow-up of https://github.com/openjdk/jdk/pull/23985.
>> 
>> Thanks
>
> test/hotspot/jtreg/compiler/vectorization/TestRoundVectFloat.java line 57:
> 
>> 55:   @IR(applyIfPlatform = {"riscv64", "true"},
>> 56:       applyIfCPUFeature = {"rvv", "true"},
>> 57:       applyIf = {"MaxVectorSize", ">= 32"},
> 
> Do you have more details about why a smaller `MaxVectorSize` (Let's say 16) won't work? Thanks.

As when RoundVF/D was implemented (https://github.com/openjdk/jdk/pull/17745), the test show e.g. RoundVF only bring performance gain when vlenb >= 32.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/24015#discussion_r1992985778