RFR: 8302814: Delete unused CountLoopEnd instruct with CmpX [v3]

[SUN Guoyun]

On Mon, 27 Feb 2023 03:32:09 GMT, Feilong Jiang <fjiang at openjdk.org> wrote:

>> SUN Guoyun has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   8302814: Delete unused CountLoopEnd instruct with CmpX
>
> src/hotspot/cpu/riscv/riscv.ad line 9297:
> 
>> 9295:   ins_pipe(pipe_cmp_branch);
>> 9296: %}
>> 9297: 
> 
> I think this instruction should keep too.

The current count loop iterations is1000(setting by `LoopStripMiningIter` ), and if it is too large, it will cause the GC pause too long, so I don't think there is any point in implementing the counted loop for Long type. However, I still respect your opinion and keep `cmpL loop` in risv.ad.

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PR: https://git.openjdk.org/jdk/pull/12648