RFR: 8262096: Vector API fails to work due to VectorShape initialization exception [v2]

[Paul Sandoz]

On Thu, 25 Feb 2021 23:48:37 GMT, Jie Fu <jiefu at openjdk.org> wrote:

>> src/hotspot/share/prims/vectorSupport.cpp line 368:
>> 
>>> 366:   if (java_lang_Class::is_primitive(mirror)) {
>>> 367:     BasicType bt = java_lang_Class::primitive_type(mirror);
>>> 368:     int min_lane_count = 64 / type2aelembytes(bt);
>> 
>> I am uncertain of the units here. Is the numerator in bits and the denominator in bytes?
>
> Thanks Paul for your review.
> 
> Oops, the numerator should be 8 (bytes).
> 
> Updated.
> Testing of jdk/incubator/vector (MaxVector=default/8/4 or without C2) is still fine.
> Thanks.

Thanks, was the test `VectorShapeInitTest` passing prior to the fix of the numerator?
Perhaps we should be testing more directly on `VectorShape.S_Max_BIT.vectorBitSize()` and `VectorShape.preferredShape` ? 
Also, perhaps we can run with C2 disabled, with `-XX:TieredStopAtLevel=3` ?

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PR: https://git.openjdk.java.net/jdk/pull/2722