<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/90287>90287</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [PPC] DoubleAPFloat frexp ignores possibility that second double affects exponent
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            backend:PowerPC
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          hubert-reinterpretcast
      </td>
    </tr>
</table>

<pre>
    In a subset of the values where `ilogb` is wrong as reported in llvm/llvm-project#89841 (but not because of the `ilogb` bug), `frexp` is also wrong:
https://github.com/llvm/llvm-project/blob/0c0c5c475857e9cd6a2fe82fd1e46abdb174a1c1/llvm/lib/Support/APFloat.cpp#L5139-L5143

For a value like `1.L - DBL_EPSILON/4.`, the correct return value is the same as the input value (as it is in the appropriate range); however, the code would return a value equal to one-half of the input value (because `1.` is not in the appropriate range).

Note: The current code is potentially more correct for `2.L - DBL_TRUE_MIN` because the purely mathematical result, when rounded, generates a result that is not in the appropriate range.
</pre>
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