<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/82367>82367</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [SCEV] applyLoopGuards drops information on compilcated SCEV builtin_assumes()
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          komalon1
      </td>
    </tr>
</table>

<pre>
    applyLoopGuards tries to rewrite a SCEV expression using assumes.
It's not working properly if the SCEV **is not** SCEVUnknown. 
For example in https://godbolt.org/z/bEs8K35Gs, the loop's trip count is `int num = num1 * num2;` and we have an assume that `__builtin_assume(num % 4 == 0);` but as can be seen, the vectorizer creates an epilogue since it cannot prove there is no tail.
</pre>
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