<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/121299>121299</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Possible miscompilation on armv7 FreeBSD 14.1
        </td>
    </tr>

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

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

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

<pre>
    Greetings,

While investigating a spurious test suite failure of the simdutf test suite, we found that the failure would only reproduce under specific circumstances:

 - recent llvm version (such as, the llvm 18.1.5 shipped with FreeBSD 14.1, but also a very recent devel snapshot)
 - build for armv7 FreeBSD
 - build with `-fno-strict-aliasing`, code works fine with `-fstrict-aliasing`

The result of the miscompilation is that wrong code is generated, leading to unit test failure.

A reduced example can be found in https://github.com/simdutf/simdutf/issues/581#issuecomment-2564785579.
</pre>
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