RFR: 8302814: Delete unused CountLoopEnd instruct with CmpX [v4]

[Feilong Jiang]

On Fri, 24 Feb 2023 05:32:20 GMT, SUN Guoyun <duke at openjdk.org> wrote:

>> CountLoopEnd only for T_int, therefore the following instructs in riscv.ad are useless and should be deleted.
>> 
>> CountedLoopEnd cmp (CmpL op1 op2)
>> CountedLoopEnd cmp (CmpU op1 op2)
>> CountedLoopEnd cmp (CmpP op1 op2)
>> CountedLoopEnd cmp (CmpN op1 op2)
>> CountedLoopEnd cmp (CmpF op1 op2)
>> CountedLoopEnd cmp (CmpD op1 op2)
>> 
>> and CountedLoopEnd with CmpU on x86*.ad, aarch64.ad ar useless also.
>> 
>> Please help review it.
>> 
>> Thanks.
>
> SUN Guoyun has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8302814: Delete unused CountLoopEnd instruct with CmpX

Changes requested by fjiang (Author).

src/hotspot/cpu/riscv/riscv.ad line 9297:

> 9295: %}
> 9296: 
> 9297: instruct cmpL_reg_imm0_loop(cmpOp cmp, iRegL op1, immL0 zero, label lbl)

I think this instruction should keep too.

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