<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/56133>56133</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            LiveVariables.cpp:129 assert failure when using both ASan and LibFuzzer instrumentation with -fast-isel
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
      </td>
    </tr>

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

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

<pre>
    ```
> ./llc -fast-isel -o /dev/null reduced.2.ll
llc: external/llvm-project/llvm/lib/CodeGen/LiveVariables.cpp:129: void llvm::LiveVariables::HandleVirtRegUse(llvm::Register, llvm::MachineBasicBlock *, llvm::MachineInstr &): Assertion `MRI->getVRegDef(Reg) && "Register use before def!"' failed.
```

Reduced IR test case: https://gist.github.com/chandlerc/7346e831145d0c00723be7e18c07b254
</pre>
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