<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/71742>71742</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            llc very slow to compile IR sample
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

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

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

<pre>
    llc is very slow to compile (45m) the attached IR after optimizations. llc 17.0.4 finishes in 3s.

At main c2ad9f8b607931430e86da7420493599c48e62a0.

Repro:
```
$ llc -version
LLVM (http://llvm.org/):
  LLVM version 18.0.0git
 Optimized build.
  Default target: 
  Host CPU: skylake-avx512

 Registered Targets:
    x86    - 32-bit X86: Pentium-Pro and above
 x86-64 - 64-bit X86: EM64T and AMD64
$ opt bad2.ll -S -O2 > opt.bad2.ll
$ llc --march=x86-64 opt.bad2.ll
....takes forever...
```

[bad2.ll.gz](https://github.com/llvm/llvm-project/files/13301751/bad2.ll.gz)

</pre>
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