RFR: 8286972: Support the new loop induction variable related PopulateIndex IR node on x86 [v2]

[Sandhya Viswanathan]

On Thu, 19 May 2022 02:59:10 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> Sandhya Viswanathan has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   review comment resolution
>
> @sviswa7 Can you add IR framework test to verify generation of PopulateIndex node? And regression test.
> I see that [8280510](https://bugs.openjdk.java.net/browse/JDK-8280510) added only microbenchmark.

@vnkozlov I will look into adding the IR framework and regression test.

> src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp line 2314:
> 
>> 2312:   } else {
>> 2313:     assert(vlen_enc != Assembler::AVX_512bit, "required");
>> 2314:     assert((dst->encoding() < 16),"XMM register should be 0-15");
> 
> The `} else {` case will be also executed on on KNL CPU. Did you tested with `-XX:+UseKNLSetting`?

Yes, this part will be executed on KNL CPU. 
I did run the compiler tests with UseKNLSetting and didn't see any issue.

-------------

PR: https://git.openjdk.java.net/jdk/pull/8778