RFR: 8342393: Promote commutative vector IR node sharing [v18]

[Emanuel Peter]

On Mon, 27 Jan 2025 10:57:30 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:
> 
>   Review comments resolutions.

I'm getting failed IR rules now:

Failed IR Rules (1) of Methods (1)
----------------------------------
1) Method "public void compiler.vectorapi.VectorCommutativeOperSharingTest.testVectorIRSharing1(int)" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#V#ADD_VI#_", "_ at any", " 2 ", "_#V#MUL_VI#_", "_ at any", " 2 ", "_#V#MAX_VI#_", "_ at any", " 2 ", "_#V#MIN_VI#_", "_ at any", " 2 "}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 2: "(\\d+(\\s){2}(MulVI.*)+(\\s){2}===.*vector[A-Za-z]<I,\\d+>)"
           - Failed comparison: [found] 0 = 2 [given]
           - No nodes matched!
         * Constraint 3: "(\\d+(\\s){2}(MaxV.*)+(\\s){2}===.*vector[A-Za-z]<I,\\d+>)"
           - Failed comparison: [found] 0 = 2 [given]
           - No nodes matched!
         * Constraint 4: "(\\d+(\\s){2}(MinV.*)+(\\s){2}===.*vector[A-Za-z]<I,\\d+>)"
           - Failed comparison: [found] 0 = 2 [given]
           - No nodes matched!

With flags: `-XX:UseAVX=0 -XX:UseSSE=3`. Machine has `AVX2`. I suspect you need to add some CPU feature restriction on the IR rule.

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PR Comment: https://git.openjdk.org/jdk/pull/22863#issuecomment-2615942159