[jdk17] RFR: 8269825: [TESTBUG] Missing testing for x86 KNL platforms

[Jatin Bhateja]

On Tue, 6 Jul 2021 16:34:29 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> Tests listed in [8269828](https://bugs.openjdk.java.net/browse/JDK-8269828) passed with additional KNL CPU features switched off as @jatin-bhateja suggested. But it does not solve our internal testing issue.
>> 
>> I will change bug's subject and flag name to be specific that it is VM emulation instead of KNL CPU.
>
> Hi @vnkozlov , 
> Thanks for clarifications, configuration of  VM guest mentions AVX512DQ feature which is not supported by KNL.
> Below is the KNL features list generated using Intel's SDE (SW Dev Emulator).
> 
> 
> 
> SPROMPT>sde -knl -- cpuid -1 | grep "AVX512" | grep "true"
>       AVX512F: AVX-512 foundation instructions = true
>       AVX512PF: prefetch instructions          = true
>       AVX512ER: exponent & reciprocal instrs   = true
>       AVX512CD: conflict detection instrs      = true
> SPROMPT>sde -knl -- cpuid -1 | grep "AVX512" | grep "false"
>       AVX512DQ: double & quadword instructions = false
>       AVX512IFMA: fused multiply add           = false
>       AVX512BW: byte & word instructions       = false
>       AVX512VL: vector length                  = false
>       AVX512VBMI: vector byte manipulation     = false
>       AVX512_VBMI2: byte VPCOMPRESS, VPEXPAND  = false
>       AVX512_VNNI: neural network instructions = false
>       AVX512_BITALG: bit count/shiffle         = false
>       AVX512: VPOPCNTDQ instruction            = false
>       AVX512_4VNNIW: neural network instrs     = false
>       AVX512_4FMAPS: multiply acc single prec  = false
>       AVX512_VP2INTERSECT: intersect mask regs = false
> 
> 
> Regards

> @jatin-bhateja
> What is your suggestion for this change? Because of my mistake about AVX512DQ I think I can just apply your additional features exclusion for KNL cpu and it will emulate VM settings we have. And I don't need separate settings for virtualization.

I agree with your suggestion. Settings enabled under UseNewCode with additional new features disabled for KNL will help in testing.

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PR: https://git.openjdk.java.net/jdk17/pull/205