On Thu, 25 Feb 2021 09:31:01 GMT, Jie Fu <jiefu@openjdk.org> wrote:

Hi all,

Vector API fails to work when: - case 1: MaxVectorSize is set to <=8, or - case 2: C2 is disabled

The reason is that {max/preferred} VectorShape initialization fails in both cases. And the root cause is that VectorSupport_GetMaxLaneCount [1] returns unreasonable values (0 for case 1 and -1 for case 2).

Vector API should not depend on C2 to run. It should work even there is no JIT compiler since it's a Java-level api. So let's fix it.

Testing: - jdk/incubator/vector with -XX:MaxVectorSize=default/8 on Linux/x64

Thanks. Best regards, Jie

[1] https://github.com/openjdk/jdk/blob/master/src/hotspot/share/prims/vectorSup...

@DamonFool that worked out better than i expected :-) One last thing i missed last time. The `PreferredSpeciesTest` also needs to be executed with no HotSpot flags. No need for another round of review. ------------- PR: https://git.openjdk.java.net/jdk/pull/2722