RFR: 8287925: AArch64: intrinsics for compareUnsigned method in Integer and Long [v2]

[Andrew Dinn]

On Mon, 5 Dec 2022 12:06:24 GMT, Hao Sun <haosun at openjdk.org> wrote:

>> x86 implemented the intrinsics for compareUnsigned() method in Integer and Long. See JDK-8283726. We add the corresponding AArch64 backend support in this patch.
>> 
>> Note-1: minor style issues are fixed for CmpL3 related rules.
>> 
>> Note-2: Jtreg case TestCompareUnsigned.java is updated to cover the matching rules for "comparing reg with imm" case.
>> 
>> Testing: tier1~3 passed on Linux/AArch64 platform with no new failures.
>> 
>> Following is the performance data for the JMH case:
>> 
>> 
>>                                                        Before          After
>> Benchmark                         (size) Mode  Cnt   Score   Error  Score   Error  Units
>> Integers.compareUnsignedDirect      500  avgt    5   0.994 ± 0.001  0.872 ± 0.015  us/op
>> Integers.compareUnsignedIndirect    500  avgt    5   0.991 ± 0.001  0.833 ± 0.055  us/op
>> Longs.compareUnsignedDirect         500  avgt    5   1.052 ± 0.001  0.974 ± 0.057  us/op
>> Longs.compareUnsignedIndirect       500  avgt    5   1.053 ± 0.001  0.916 ± 0.038  us/op
>
> Hao Sun has updated the pull request incrementally with one additional commit since the last revision:
> 
>   immIAddSub is always positive
>   
>   As commented by aph, "immIAddSub" is always positive and we needn't
>   check the signedness.
>   
>   Besides, more "comparing reg with imm" test cases are added.

New changes are fine

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Marked as reviewed by adinn (Reviewer).

PR: https://git.openjdk.org/jdk/pull/11383