RFR: JDK-8298880: VectorLogicalOpIdentityTest.java IR test incorrectly use avx3 instead of avx512

[Damon Fenacci]

On Wed, 1 Feb 2023 09:31:25 GMT, Roberto Castañeda Lozano <rcastanedalo at openjdk.org> wrote:

> Did you try to run the tests with different `UseSSE` values, as it is done in some of our internal CI tiers? We recently discovered (while working on [JDK-8294715](https://bugs.openjdk.org/browse/JDK-8294715)) that SSE and AVX levels sometimes can interact and affect vectorization in non-trivial ways.

@robcasloz it looks as if `UseSSE=4` is needed for any AVX level >0. For instance the VM gives me a message like _UseAVX=3 requires UseSSE=4, setting it to UseAVX=0_ if I force both flags. With AVX set to 0 this test then doesn't run due to the _ at requires_ header.

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PR: https://git.openjdk.org/jdk/pull/12358