<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/59599>59599</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang Backend Error after D131047
        </td>
    </tr>

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

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

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

<pre>
    I bisected a clang backend crash to https://reviews.llvm.org/D131047 and made minimal reproducer:

```
int main() {
    long j = __builtin_neon_vmull_p64(0, 0);
    return __builtin_arm_crc32cd(0, j) ;
}
```

Crashes with:

```
fatal error: error in backend: Cannot select: t23: v16i8 = AArch64ISD::PMULL t22, t22
  t22: v1i64 = scalar_to_vector Constant:i64<0>
    t3: i64 = Constant<0>
 t22: v1i64 = scalar_to_vector Constant:i64<0>
    t3: i64 = Constant<0>
In function: main
```

When compiled with `clang -cc1 -triple aarch64-cros-linux-gnu -emit-obj -target-feature +crc reduced_test_case.cpp`

Compiler Explorer Link: https://godbolt.org/z/7EbTxWqsn

This bug is still present at TOT.

</pre>
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