RFR: 8342393: Promote commutative vector IR node sharing [v20]

[Emanuel Peter]

On Tue, 28 Jan 2025 11:46:33 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> Patch promotes the sharing of commutative vector IR with the same inputs but different input ordering.
>> Similar to scalar IR where we perform edge swapping by [sorting inputs](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/opto/addnode.cpp#L122) based on node indices during IR idealization.
>> 
>> Following are the performance stats for JMH micro included with the patch.
>> 
>> 
>> Granite Rapids (P-core Xeon Server)
>> Baseline : 
>> Benchmark                                                                (size)   Mode  Cnt      Score   Error   Units
>> VectorCommutativeOperSharingBenchmark.commutativeByteOperationShairing     1024  thrpt    2   8982.549          ops/ms
>> VectorCommutativeOperSharingBenchmark.commutativeIntOperationShairing      1024  thrpt    2   6072.773          ops/ms
>> VectorCommutativeOperSharingBenchmark.commutativeLongOperationShairing     1024  thrpt    2   2368.856          ops/ms
>> VectorCommutativeOperSharingBenchmark.commutativeShortOperationShairing    1024  thrpt    2  15215.087          ops/ms
>> 
>> Withopt:
>> Benchmark                                                                (size)   Mode  Cnt      Score   Error   Units
>> VectorCommutativeOperSharingBenchmark.commutativeByteOperationShairing     1024  thrpt    2  11963.554          ops/ms
>> VectorCommutativeOperSharingBenchmark.commutativeIntOperationShairing      1024  thrpt    2   7036.088          ops/ms
>> VectorCommutativeOperSharingBenchmark.commutativeLongOperationShairing     1024  thrpt    2   2906.731          ops/ms
>> VectorCommutativeOperSharingBenchmark.commutativeShortOperationShairing    1024  thrpt    2  17148.131          ops/ms
>> 
>> Sierra Forest (E-core Xeon Server)
>> Baseline:
>> Benchmark                                                                (size)   Mode  Cnt     Score   Error   Units
>> VectorCommutativeOperSharingBenchmark.commutativeByteOperationShairing     1024  thrpt    2  2444.359          ops/ms
>> VectorCommutativeOperSharingBenchmark.commutativeIntOperationShairing      1024  thrpt    2  1710.256          ops/ms
>> VectorCommutativeOperSharingBenchmark.commutativeLongOperationShairing     1024  thrpt    2   308.766          ops/ms
>> VectorCommutativeOperSharingBenchmark.commutativeShortOperationShairing    1024  thrpt    2  3902.179          ops/ms
>> 
>> Withopt:
>> Benchmark                                                                (size)   Mode  Cnt     Score   Error   Units
>> VectorCommutativeOperSharingBenchmark.com...
>
> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Adding required target constraint

test/hotspot/jtreg/compiler/vectorapi/VectorCommutativeOperSharingTest.java line 38:

> 36:  * @library /test/lib /
> 37:  * @summary Promote vector IR node sharing
> 38:  * @requires (os.simpleArch == "x64")

Oh, I see you added it here, rather than at each IR rule. It would be nice to have this test also execute on other machines, for additional coverage.

Can you instead simply restrict it with `avx` features? And if that is not enough, and you do need 64bit restriction, then use this:
`applyIfPlatform = {"64-bit", "true"}`

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PR Review Comment: https://git.openjdk.org/jdk/pull/22863#discussion_r1935318625