<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/139005>139005</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [AArch64] Why doesn't clang generate stp/ldp for 256-bit value ?
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          Zhenhang1213
      </td>
    </tr>
</table>

<pre>
    In arm [document](https://developer.arm.com/documentation/ka004805/latest/): it shows that if use keywords like volatile with a 128-bit structure type, it is possible to treat two 64-bit values as a 128-bit value. I have confirmed this works in Clang/GCC. However, when I extend this to a 256-bit data structure, LLVM cannot handle it while GCC can. Is it possible to extend LLVM's behavior?

demo:
https://godbolt.org/z/Eoj454o6T
</pre>
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