<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/59565>59565</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Any option that enable loop inversion?
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          2994186010
      </td>
    </tr>
</table>

<pre>
    Are there any options that enable loop inversion?  More specifically，can LLVM transform the while form loop into do-while form loop as the following.

Before the transformation, the code is:
`
void foo(unsigned a, unsigned& ret) {
  bool undone = true;
  #pragma unroll 4
  while((a > 0) && undone) {
    ++ret;
    if(ret > 2)    undone = false;
    if(undone)   --a;
  }
}
`

After the transformation, the code is:
`
void foo(unsigned a, unsigned& ret) {
  bool undone = true;
  #pragma unroll 4
  while((a > 0) && undone) {
    ++ret;
    if(ret > 2)    undone = false;
    if(undone)   --a;
  }
}
`
</pre>
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