<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/118847>118847</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [DAG] SDPatternMatch - add matchers for reassociatable binops
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            good first issue,
            llvm:SelectionDAG
      </td>
    </tr>

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

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

<pre>
    For binop opcodes that are commutable + reassociatable (ISD::AND/OR/OR/ADD/MUL etc.) we need support for a variable args matchers that can match operands that might be in different locations in a dependency chain:

e.g.
```
(add X, (add Y, Z))
(add (add X, Y), (add Z, W))
(add X, (add Y, (add Z, W)))

SDValue X, Y, Z, W;
m_Add(m_Value(X), m_Value(Y), m_Value(Z))
m_Add(m_Value(X), m_Value(Y), m_Value(Z), m_Value(W))
```
</pre>
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