RFR: 8262508: Vector API's ergonomics is incorrect [v2]

[Vladimir Ivanov]

On Mon, 1 Mar 2021 06:01:26 GMT, Jie Fu <jiefu at openjdk.org> wrote:

>> Hi all,
>> 
>> The ergonomics (e.g., EnableVectorReboxing/EnableVectorAggressiveReboxing) for Vector API doesn't work as expected.
>> 
>> There are two sets of rules for Vector API.
>> One is in Arguments::apply_ergo() [1], which sets the flags to be false.
>> And the other is in Modules::define_module() [2], which sets the flags to be true.
>> 
>> The value of EnableVectorReboxing and EnableVectorAggressiveReboxing may be changed (from specified true to false) in [1] if EnableVectorSupport=false (which is the default value).
>> It would be wrong when EnableVectorSupport isn't specified in the command line since it will be set true later in [2]
>> So rules in [1] should not be executed if EnableVectorSupport isn't specified.
>> 
>> Thanks.
>> Best regards,
>> Jie
>> 
>> [1] https://github.com/openjdk/jdk/blob/master/src/hotspot/share/runtime/arguments.cpp#L4081
>> [2] https://github.com/openjdk/jdk/blob/master/src/hotspot/share/classfile/modules.cpp#L462
>
> Jie Fu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Require C2 to run the test

Looks good. 

Thanks for fixing it.

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Marked as reviewed by vlivanov (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/2771