RFR(L): JDK-8222525 : [lworld] Runtime support for LW2 Arrays

[Tobias Hartmann]

Hi Mr. Simms,

On 16.04.19 10:46, David Simms wrote:
> Please review runtime support for LW2 array covariance[1]:
> 
> http://cr.openjdk.java.net/~dsimms/valhalla/lw2_arrays/webrev5/

This looks good to me and works well with my C2 fix [1].

> Further testing is needed, but requires javac (for ease of writing)

Yes, as soon as javac supports widening of [Q to [L, we need to implement runtime and JIT support
for that (and add tests). A quick javac hack that I did suggests that some sophisticated changes are
required to support widening.

Thanks,
Tobias

[1] http://mail.openjdk.java.net/pipermail/valhalla-dev/2019-April/005590.html