RFR: 8356924: RISC-V: Clean up cost for vector instructions [v2]

[Fei Yang]

On Tue, 20 May 2025 08:40:35 GMT, Dingli Zhang <dzhang at openjdk.org> wrote:

>> As mentioned in https://bugs.openjdk.org/browse/JDK-8285790 regarding the ARM64 vector instruct modifications:
>> Since the new rules are unique and setting different "ins_cost" makes no sense, we have switched to using the default cost.
>> 
>> Currently, there is a similar situation on RISC-V. Over half of the instructions in riscv_v.ad do not include ins_cost definitions. Additionally, as RVV nodes are also unique, we can unify the format by removing these ins_cost entries from riscv_v.ad.
>> 
>> ### Testing
>> qemu-system 9.2.3 with UseRVV (ubuntu24.10):
>> * [x]  Run test/jdk/jdk/incubator/vector (fastdebug)
>> * [x]  Run test/hotspot/jtreg/compiler/vectorapi (fastdebug)
>
> Dingli Zhang has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - Remove added ins_cost(VEC_COST) due to merging the main branch
>  - Merge branch 'master' into master-remove-ins_cost
>  - 8356924: RISC-V: Clean up cost for vector instructions

Thanks!

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Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/25221#pullrequestreview-2856863293