RFR: 8303627: compiler/loopopts/TestUnreachableInnerLoop.java failed with -XX:LoopMaxUnroll=4

[Christian Hagedorn]

On Mon, 6 Mar 2023 02:42:21 GMT, SUN Guoyun <duke at openjdk.org> wrote:

> This test failed with VM_OPTIONS=-XX:LoopMaxUnroll=4 and CONF=fastdebug on X86_64, AArch64 LoongArch64 architecture.
> 
> <pre><code class="shell">
> # A fatal error has been detected by the Java Runtime Environment:
> #
> # Internal Error (/home/sunguoyun/jdk-ls/src/hotspot/share/opto/block.cpp:1359), pid=31328, tid=31344
> # assert(n->is_Root() || n->is_Region() || n->is_Phi() || n->is_MachMerge() || def_block->dominates(block)) failed: uses must be dominated by definitions
> #
> </code></pre>
> This PR fix the issue, Please help review it.
> 
> Thanks.

It indeed seems like a dup of [JDK-8291025](https://bugs.openjdk.org/browse/JDK-8291025) and eventually [JDK-8288981](https://bugs.openjdk.org/browse/JDK-8288981). But I'm currently out of the office until the end of the week, so I cannot verify it - will have a look again when I'm back to work.

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PR: https://git.openjdk.org/jdk/pull/12874