<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/78727>78727</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang crash compiling ffmpeg on AArch64 Linux with EXPENSIVE_CHECKS enabled
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang
      </td>
    </tr>

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

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

<pre>
    To reproduce build clang from `main` (`535b197b8e96b816998ad4b4ee45e011fa05fba9` at this time) with `EXPENSIVE_CHECKS` enabled, then build ffmpeg:
```
$ git clone https://github.com/ffmpeg/ffmpeg
$ cd ffmpeg
$ git checkout 65739691b90012c9d93b2e5e0e89a55d8de9eb7b
$ cd ..
$ mkdir ffmpeg-build
$ cd ffmpeg-build
$ ../ffmpeg/configure --cc=<path/to/built/clang>
$ make -j$(nproc) fate-checkasm
```

```
clang: error: clang frontend command failed with exit code 134 (use -v to see invocation)
clang version 18.0.0git (https://github.com/llvm/llvm-project.git 535b197b8e96b816998ad4b4ee45e011fa05fba9)
Target: aarch64-unknown-linux-gnu
```

Or use the single file reproducer that clang made:
```
$ ./vf_chromakey-76c8c6.sh
clang-18: /home/david.spickett/llvm-project/llvm/lib/CodeGen/MachineCombiner.cpp:562: void (anonymous namespace)::MachineCombiner::verifyPatternOrder(llvm::MachineBasicBlock *, llvm::MachineInstr &, SmallVector<llvm::MachineCombinerPattern, 16> &): Assertion `CurrentLatencyDiff <= PrevLatencyDiff && "Current pattern is better than previous pattern."' failed.
```
[vf_chromakey-76c8c6.zip](https://github.com/llvm/llvm-project/files/13991028/vf_chromakey-76c8c6.zip)


</pre>
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