<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/64280>64280</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [MLIR] In-place folds lead to invalid attributes being passed to `foldTraits`
        </td>
    </tr>

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

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

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

<pre>
    When an operation does an "in-place fold", we later call the `foldTraits` method using the same attribute array `operands` which was passed to the folder.

https://github.com/llvm/llvm-project/blob/29b1af7396b0839f076ca0a8ae3a5ac47ed55ee7/mlir/include/mlir/IR/OpDefinition.h#L1912-L1944

If the operation's folder modifies the op's operands, by adding, deleting, or shuffling, then the `operands` array will be invalid. The `operands` array should be updated each time any folder (op or trait) does an in-place fold.

Right now this is manifesting in a CIRCT folder, where an op gains an additional argument in its folder, and then crashes in the `commutative` folder as the `operands` array is short one element.
</pre>
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