RFR: 8287794: Reverse*VNode::Identity problem [v2]

[Tobias Hartmann]

On Mon, 25 Jul 2022 05:29:05 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> Hi All,
>> 
>> - This bug fix patch fixes a missing case during reverse[bits|bytes] identity transformation.
>> - Unlike AARCH64(SVE), X86(AVX512) ISA has no direct instruction to reverse[bits|bytes] of a vector lane hence a predicated operation is supported through blend instruction.
>> - New IR framework based tests has been added to test transforms relevant to AVX2, AVX512 and SVE.
>> 
>> Kindly review and share your feedback.
>> 
>> Best Regards,
>> Jatin
>
> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8287794: Review comments resolved.

Changes requested by thartmann (Reviewer).

src/hotspot/share/opto/vectornode.cpp line 1864:

> 1862:     // OperationV (OperationV X) =>  X
> 1863:     } else if (!n->is_predicated_vector() && !in1->is_predicated_vector())  {
> 1864:       return in1->in(1);

But this will still trigger the SonarCloud warning originally reported by @shipilev because both if and else branch contain the same code, right? Shouldn't the conditions be merged?

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PR: https://git.openjdk.org/jdk/pull/9623