<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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