RFR: 8319429: Resetting MXCSR flags degrades ecore [v2]

[Jatin Bhateja]

On Tue, 7 Nov 2023 02:57:55 GMT, Volodymyr Paprotski <duke at openjdk.org> wrote:

>> Volodymyr Paprotski has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   move option to x86-specific section
>
> src/hotspot/cpu/x86/vm_version_x86.cpp line 862:
> 
>> 860:   // Check if processor has Intel Ecore
>> 861:   if (FLAG_IS_DEFAULT(DoEcoreOpt) && is_intel() && cpu_family() == 6 &&
>> 862:     (_model == 0x97 || _model == 0xAC || _model == 0xAF)) {
> 
> On hybrid platforms, it will be enabled on both Pcore and Ecore. Performance is essentially unchanged on Pcore

Correct, CPUID is CPU specific not core specific, so settings should apply to both.

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PR Review Comment: https://git.openjdk.org/jdk/pull/16504#discussion_r1384297045