<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/60927>60927</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [LSR] Assertion failure: No dominance between recurrences used by one SCEV?
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            regression,
            llvm:optimizations,
            crash
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
            davemgreen
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          vzakhari
      </td>
    </tr>
</table>

<pre>
    The issue affects SPEC CPU2017/521.wrf compiled with Flang.  The assertion started kicking in after https://reviews.llvm.org/D144014

This is llvm-reduce'd reproducer: [reduced.ll.gz](https://github.com/llvm/llvm-project/files/10808264/reduced.ll.gz)

I was not able to reproduce the issue with an `opt` invocation, so here is the `clang` command to reproduce: `clang -cc1 -emit-obj -O2 -x ir reduced.ll`
```
clang: /llvm-project/llvm/lib/Analysis/ScalarEvolution.cpp:744: std::optional<int> CompareSCEVComplexity(llvm::EquivalenceClasses<const llvm::SCEV*>&, llvm::EquivalenceClasses<const llvm::Value*>&, const llvm::LoopInfo*, const llvm::SCEV*, const llvm::SCEV*, llvm::DominatorTree&, unsigned int): Assertion `DT.dominates(RHead, LHead) && "No dominance between recurrences used by one SCEV?"' failed.
```

If I revert 7abe3497e72af3ddee789dfc62c63a981a25dbf6 the compilation passes.

@davemgreen can you please take a look?
</pre>
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