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

[Nils Eliasson]

On Wed, 19 May 2021 08:26:24 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

Looks good.

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Marked as reviewed by neliasso (Reviewer).

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