<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/78206>78206</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            `LLVM ERROR: Do not know how to split the result of this operator!` on AVX-512-VNNI intrinsic
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            backend:X86,
            llvm:codegen
      </td>
    </tr>

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

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

<pre>
    Testcase (`reduced.ll`):

```llvm
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-unknown-eabi-elf"

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(none)
declare <16 x i32> @llvm.x86.avx512.vpdpbusd.512(<16 x i32>, <16 x i32>, <16 x i32>) #0

define void @foo() {
  %1 = tail call <16 x i32> @llvm.x86.avx512.vpdpbusd.512(<16 x i32> zeroinitializer, <16 x i32> zeroinitializer, <16 x i32> zeroinitializer)
  store <16 x i32> %1, ptr null, align 1
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(none) }
```

Reproduction command line:

```
llc reduced.ll
```

Result:

```
SplitVectorResult #0: t4: v16i32 = llvm.x86.avx512.vpdpbusd.512 TargetConstant:i64<12832>, t3, t3, t3

LLVM ERROR: Do not know how to split the result of this operator!

PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: /home/benoit/iree-build/llvm-project/bin/llc /home/benoit/iree-build/reduced.ll
1.      Running pass 'Function Pass Manager' on module '/home/benoit/iree-build/reduced.ll'.
2.      Running pass 'X86 DAG->DAG Instruction Selection' on function '@foo'
 #0 0x000055a2dff2a8e8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/benoit/iree/third_party/llvm-project/llvm/lib/Support/Unix/Signals.inc:723:13
 #1 0x000055a2dff28b00 llvm::sys::RunSignalHandlers() /home/benoit/iree/third_party/llvm-project/llvm/lib/Support/Signals.cpp:106:18
 #2 0x000055a2dff2b0b8 SignalHandler(int) /home/benoit/iree/third_party/llvm-project/llvm/lib/Support/Unix/Signals.inc:413:1
 #3 0x00007f9d91c42910 (/lib/x86_64-linux-gnu/libc.so.6+0x42910)
 #4 0x00007f9d91c9999b __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 #5 0x00007f9d91c9999b __pthread_kill_internal ./nptl/pthread_kill.c:78:10
 #6 0x00007f9d91c9999b pthread_kill ./nptl/pthread_kill.c:89:10
 #7 0x00007f9d91c42866 gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #8 0x00007f9d91c268b7 abort ./stdlib/abort.c:81:7
 #9 0x000055a2dfea76d5 llvm::report_fatal_error(llvm::Twine const&, bool) /home/benoit/iree/third_party/llvm-project/llvm/lib/Support/ErrorHandling.cpp:125:5
#10 0x000055a2dfea7516 (/home/benoit/iree-build/llvm-project/bin/llc+0x363a516)
#11 0x000055a2dfdae521 (/home/benoit/iree-build/llvm-project/bin/llc+0x3541521)
#12 0x000055a2dfd7073a llvm::DAGTypeLegalizer::run() /home/benoit/iree/third_party/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp:0:9
#13 0x000055a2dfd74c37 llvm::SelectionDAG::LegalizeTypes() /home/benoit/iree/third_party/llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp:1058:34
#14 0x000055a2dfd5de53 llvm::SelectionDAGISel::CodeGenAndEmitDAG() /home/benoit/iree/third_party/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:844:23
#15 0x000055a2dfd5c769 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) /home/benoit/iree/third_party/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1511:8
#16 0x000055a2dfd59a9c llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) /home/benoit/iree/third_party/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:517:7
#17 0x000055a2de9687d9 (anonymous namespace)::X86DAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) /home/benoit/iree/third_party/llvm-project/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:192:7
#18 0x000055a2df4be959 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /home/benoit/iree/third_party/llvm-project/llvm/lib/CodeGen/MachineFunctionPass.cpp:0:13
#19 0x000055a2df91ca11 llvm::FPPassManager::runOnFunction(llvm::Function&) /home/benoit/iree/third_party/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1443:27
#20 0x000055a2df922853 llvm::FPPassManager::runOnModule(llvm::Module&) /home/benoit/iree/third_party/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1489:13
#21 0x000055a2df91d11e (anonymous namespace)::MPPassManager::runOnModule(llvm::Module&) /home/benoit/iree/third_party/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:0:27
#22 0x000055a2df91d11e llvm::legacy::PassManagerImpl::run(llvm::Module&) /home/benoit/iree/third_party/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:541:44
#23 0x000055a2de638dc2 compileModule(char**, llvm::LLVMContext&) /home/benoit/iree/third_party/llvm-project/llvm/tools/llc/llc.cpp:751:17
#24 0x000055a2de638dc2 main /home/benoit/iree/third_party/llvm-project/llvm/tools/llc/llc.cpp:425:22
#25 0x00007f9d91c280d0 __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#26 0x00007f9d91c28189 call_init ./csu/../csu/libc-start.c:128:20
#27 0x00007f9d91c28189 __libc_start_main ./csu/../csu/libc-start.c:347:5
#28 0x000055a2de6368e5 _start (/home/benoit/iree-build/llvm-project/bin/llc+0x1dc98e5)
Aborted (core dumped)
```

</pre>
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