RFR: 8355293: [TEST] RISC-V: enable more ir tests [v2]

[Hamlin Li]

On Thu, 24 Apr 2025 02:49:55 GMT, Fei Yang <fyang at openjdk.org> wrote:

>> Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   copyright
>
> test/hotspot/jtreg/compiler/loopopts/superword/ProdRed_Double.java line 94:
> 
>> 92:     @IR(applyIfPlatform = {"riscv64", "true"},
>> 93:         applyIf = {"SuperWordReductions", "true"},
>> 94:         failOn = {IRNode.MUL_REDUCTION_VF})
> 
> I think we can just leave this two test files (`ProdRed_Float.java`/`ProdRed_Double.java`) untouched?
> The IR check is only enabled for x86 sse2 target for now. It does not apply to other CPUs. So I don't see why RISC-V is special here.

I added these `failOn` checks for several reasons:
1. It's more clear for user reading the code in the future why we have Mul Reduction for int/long but not for float/double.
2. catch any *wrong* attemp to implement these instructs in the future, unless we have an efficient way to implement the ordered computation. For this one, we could catch it manually by reviewing code, but it's always better to do it automatically.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/24797#discussion_r2058006403