RFR: 8298935: fix cyclic dependency bug in create_pack logic in SuperWord::find_adjacent_refs [v9]

[Jatin Bhateja]

On Fri, 24 Feb 2023 14:52:15 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> test/hotspot/jtreg/compiler/loopopts/superword/TestCyclicDependency.java line 32:
>> 
>>> 30:  * @requires vm.compiler2.enabled
>>> 31:  * @library /test/lib /
>>> 32:  * @run driver TestCyclicDependency
>> 
>> Hi @eme64 , can you extend one of the test point to cover various cases for MaxVectorSizes,  and AlignVector combinations and add multiple IR rules with relevant constraints. 
>> e.g.  
>>   iArr[ i + 4] = iArr[i];     // Vectorize if MaxVectorSize=16 but for 32/64, +AlignVector
>>   iArr[ i + 7] = iArr[i];     // Vectorize for MaxVectorSize=16,  -AlignVector
>> 
>> PS:  SuperWord operates under SuperWordMaxVectorSize flag.
>
> @jatin-bhateja Ok, I have reconsidered it. I will add some `SuperWordMaxVectorSize` and `AlignVector` combinations. But I will do it in a separate file, and always have CompileCommand directive `Vectorize` enabled (`_do_vector_loop == true`). I might refactor `TestOptionVectorizeIR.java` for that.
> Let me know if you find it essencial to have the tests also with `_do_vector_loop == false`.

Sounds good.

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PR: https://git.openjdk.org/jdk/pull/12350