[jdk18] RFR: 8278948: compiler/vectorapi/reshape/TestVectorCastAVX1.java crashes in assembler [v2]

Thu Dec 23 17:07:10 UTC 2021

On Thu, 23 Dec 2021 16:44:54 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> Hi, while the instruction is supported in hardware, the VM does not support the vector shape. As a result, there should not be a situation where we have a vector node with that shape on AVX1. Thank you very much.
>
> Why do you think that? What about this code when length is the same (and UseAVX could be 1):
> https://github.com/openjdk/jdk18/blob/master/src/hotspot/cpu/x86/x86.ad#L7069

Because the input of `VectorCastI2XNode` would be a vector node of type int and size 256, this shape is not supported on AVX1. So, we should not have this node because its input should not appear.

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PR: https://git.openjdk.java.net/jdk18/pull/46