<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/167178>167178</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Missed Optimization: simplify ((x lshr 9) + x) < 256 to x < 256
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          Leo0506
      </td>
    </tr>
</table>

<pre>
    ```
define i1 @src(i32 %arg0) {
  %v0 = lshr i32 %arg0, 9
  %v1 = add nuw i32 %v0, %arg0
  %v2 = icmp ult i32 %v1, 256
 ret i1 %v2
}

define i1 @tgt(i32 %arg0) {
  %v2 = icmp ult i32 %arg0, 256
  ret i1 %v2
}
```
alive2: https://alive2.llvm.org/ce/z/Ab_dJk
godbolt: https://godbolt.org/z/nYo8114Wq
Pattern found in: https://github.com/dtcxzyw/llvm-opt-benchmark/blob/main/bench/ffmpeg/optimized/webp.ll
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJx8kk9vnDAQxT_NcLGysocFw4EDaeRD1aq9VT1VBg-7bgym2Oxu8ukryLL9l0ZCCHt-w7x5ejoEexiIKsjuIXtI9ByPfqo-kOcZz5PGm6cKcn59eG2oswMxKxjseZhawMKmyAAzPR04YMlA3gOv2XJ14gzSB-bCcWJ_UO9YeWPEymhj2DCfN-y0Qhu_obiitu1HNrt4Y8XCYpYv3ERxFbfQwGuQD8v7L93xEN_W_fqgTft11H9m_WaWdvZECGnNjjGOAdIaUAGql_udc6d-56cDoGoJUD0Dqrr5Zt4_Aq8P3jTexX-br4Vr49IzfPWFEPsvP4DXn3WMNA2s8_NgmB1e6bfxODe71veAysT28vx0BlSLmDs_xruGhvbY6-kRUDXON4Cq13ZYTksFUHVdP9Iy3I_R9vaZDKA6UzPunEtMlZoyLXVClZA55mnOEZNjlcs8JykkZlnGu8IUWso9LwuZauzyJktshRwzIXiBgkuOO94hypL2eSdS2SHBnlOvrbv5ltgQZqpELoUsEqcbcmHNMeJAZ7ZWAXGJ9VSt-zXzIcCeOxti-PWbaKOj6qMNgQz79LKTjtav5gXbj852TwywACwuL2ku18TgPbusH-kaChY9u2yHZJ5c9Ybzy_TN9nHy36mNgGrVHADVdalThT8DAAD__xM9DVY">