RFR: 8321021: RISC-V: C2 VectorUCastB2X [v5]

[Hamlin Li]

On Wed, 13 Mar 2024 13:29:32 GMT, Fei Yang <fyang at openjdk.org> wrote:

>> Hamlin Li has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 10 commits:
>> 
>>  - merge master
>>  - remove ucast from i/s/b to float
>>  - revert some chnage; remove effect(TEMP_DEF dst) for non-extending intrinsics
>>  - fix typo
>>  - modify test config
>>  - clean code
>>  - add more tests
>>  - rearrange tests layout
>>  - merge master
>>  - Initial commit
>
> src/hotspot/cpu/riscv/assembler_riscv.hpp line 1284:
> 
>> 1282:   INSN(vfwcvt_f_f_v,      0b1010111, 0b001, 0b01100, 0b010010);
>> 1283:   INSN(vfwcvt_rtz_x_f_v,  0b1010111, 0b001, 0b01111, 0b010010);
>> 1284:   INSN(vfwcvt_rtz_xu_f_v, 0b1010111, 0b001, 0b01110, 0b010010);
> 
> I see no use of these newly added assembler functions. So test coverage would be an issue. Maybe add them in the future when they are really needed?

Sure, will fix.

> src/hotspot/cpu/riscv/riscv_v.ad line 3215:
> 
>> 3213: %}
>> 3214: 
>> 3215: instruct vcvtUBtoX_extend(vReg dst, vReg src) %{
> 
> Personally, I don't like the `_extend` suffix in the instruct name. I prefer names like `vzeroExtBtoX` which make it explicit that this will zero-extend the vector elements. Or simply `vcvtUBtoX`.

Agree

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PR Review Comment: https://git.openjdk.org/jdk/pull/18040#discussion_r1523595888
PR Review Comment: https://git.openjdk.org/jdk/pull/18040#discussion_r1523599044