<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/140658>140658</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            How to support plenty of RISC-V Custom Instruction Extensions？
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          TJU-PanYizhe
      </td>
    </tr>
</table>

<pre>
    RISC-V allows developers to introduce new custom instructions. Compiler(LLVM) needs modification to support diverse custom instructions.

Is it necessory to support every custom instruction proposed by vendors or in papers?

Maintaining a fork of LLVM for every custom instruction extension causes laborious manual effort. Moreover, merging conflict may happen when merging the newest code with the fork.

7 new custom instruction extensions are proposed at most per month in papers from arXiv.
</pre>
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