RFR: 8271366: [REDO] JDK-8266054 VectorAPI rotate operation optimization [v2]

[Jatin Bhateja]

On Fri, 30 Jul 2021 18:25:16 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

>> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   8271366: Test failure and review resolutions.
>
> src/hotspot/share/opto/vectornode.cpp line 311:
> 
>> 309:   // If target does not support variable shift operations then no point
>> 310:   // in creating a rotate vector node since it will not be disintegratable.
>> 311:   int has_scalar_shift = n->in(2)->Opcode() != Op_LoadI;
> 
> Why is this decision not made on type but opcode? Are we sure that the Opcode will be Op_LoadI from all paths?

Type will be an integer always since scalar rotation APIs accept only integral shits.

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PR: https://git.openjdk.java.net/jdk/pull/4924