<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/154492>154492</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [x86] LLVM ERROR: Cannot select: t28: v8i32 = X86ISD::CVTTP2UI t27
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            backend:X86,
            crash
      </td>
    </tr>

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

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

<pre>
    ```llvm
; RUN: llc -mattr=+avx512f < %s
define <16 x i32> @test() {
  %res = call <16 x i32> @llvm.x86.avx512.mask.cvttps2udq.512(<16 x float> zeroinitializer, <16 x i32> zeroinitializer, i16 255, i32 4)
  ret <16 x i32> %res
}
```
Results in:
```
LLVM ERROR: Cannot select: t28: v8i32 = X86ISD::CVTTP2UI t27
  t27: v8f32 = BUILD_VECTOR ConstantFP:f32<0.000000e+00>, ConstantFP:f32<0.000000e+00>, ConstantFP:f32<0.000000e+00>, ConstantFP:f32<0.000000e+00>, ConstantFP:f32<0.000000e+00>, ConstantFP:f32<0.000000e+00>, ConstantFP:f32<0.000000e+00>, ConstantFP:f32<0.000000e+00>
```

Note that CVTTP2UI originally had v16i32 result and was narrowed to v8i32, so it now requires `+avx512vl` as well, leading to a selection failure.
</pre>
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