RFR: 8267370: [Vector API] Fix several crashes after JDK-8256973 [v2]

[Jie Fu]

On Wed, 19 May 2021 11:23:05 GMT, Jie Fu <jiefu at openjdk.org> wrote:

>> Hi all,
>> 
>> Several vector tests fail with UseAVX=1 after JDK-8256973.
>> The reason is that `vpmovmskb` [1] can be only used with UseAVX > 1 [2].
>> The fix just disables the intrinsics when UseAVX < 2.
>> 
>> Testing:
>>  - jdk/incubator/vector with UseAVX={0/1/2/3} on Linux/x64
>> 
>> Thanks.
>> Best regards,
>> Jie
>> 
>> [1] https://github.com/openjdk/jdk/blob/master/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp#L3785
>> [2] https://github.com/openjdk/jdk/blob/master/src/hotspot/cpu/x86/assembler_x86.cpp#L4127
>
> Jie Fu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Enable vpmovmskb for 128-bit vectors

Could someone help to review this fix?

I've noticed that JDK-8267519 was also filed about the same crash just now.
Thanks.

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PR: https://git.openjdk.java.net/jdk/pull/4109