[BUG] Compiler crash in LLVM APIntOps::ScaleBitMask

[adityasz]

Bug description

$ mojo build main.mojo
Please submit a bug report to https://github.com/modularml/mojo/issues and include the crash backtrace along with all the relevant source codes.
Stack dump:
0.	Running pass 'Function Pass Manager' on module ''.
1.	Running pass 'X86 DAG->DAG Instruction Selection' on function '@main'
 #0 0x0000559d94b3ae4b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) Signals.cpp:0:0
 #1 0x0000559d94b38da9 llvm::sys::RunSignalHandlers() Signals.cpp:0:0
 #2 0x0000559d94b3b4cd SignalHandler(int) Signals.cpp:0:0
 #3 0x00007f6b96cec090 __restore_rt (/lib64/libc.so.6+0x1a090)
 #4 0x0000559d94ae6e8d llvm::APIntOps::ScaleBitMask(llvm::APInt const&, unsigned int, bool) APInt.cpp:0:0
 #5 0x0000559d938a7462 llvm::SelectionDAG::computeKnownBits(llvm::SDValue, llvm::APInt const&, unsigned int) const SelectionDAG.cpp:0:0
 #6 0x0000559d938a2dab llvm::SelectionDAG::computeKnownBits(llvm::SDValue, unsigned int) const SelectionDAG.cpp:0:0
 #7 0x0000559d938a4ff0 llvm::SelectionDAG::computeKnownBits(llvm::SDValue, llvm::APInt const&, unsigned int) const SelectionDAG.cpp:0:0
 #8 0x0000559d93a1031c llvm::TargetLowering::SimplifyDemandedBits(llvm::SDValue, llvm::APInt const&, llvm::APInt const&, llvm::KnownBits&, llvm::TargetLowering::TargetLoweringOpt&, unsigned int, bool) const TargetLowering.cpp:0:0
 #9 0x0000559d93a097a4 llvm::TargetLowering::SimplifyDemandedBits(llvm::SDValue, llvm::APInt const&, llvm::APInt const&, llvm::KnownBits&, llvm::TargetLowering::TargetLoweringOpt&, unsigned int, bool) const TargetLowering.cpp:0:0
#10 0x0000559d93a0a06c llvm::TargetLowering::SimplifyDemandedBits(llvm::SDValue, llvm::APInt const&, llvm::APInt const&, llvm::KnownBits&, llvm::TargetLowering::TargetLoweringOpt&, unsigned int, bool) const TargetLowering.cpp:0:0
#11 0x0000559d93a07032 llvm::TargetLowering::SimplifyDemandedBits(llvm::SDValue, llvm::APInt const&, llvm::APInt const&, llvm::KnownBits&, llvm::TargetLowering::TargetLoweringOpt&, unsigned int, bool) const TargetLowering.cpp:0:0
#12 0x0000559d92f7417c llvm::X86TargetLowering::SimplifyDemandedBitsForTargetNode(llvm::SDValue, llvm::APInt const&, llvm::APInt const&, llvm::KnownBits&, llvm::TargetLowering::TargetLoweringOpt&, unsigned int) const X86ISelLowering.cpp:0:0
#13 0x0000559d93a0a81c llvm::TargetLowering::SimplifyDemandedBits(llvm::SDValue, llvm::APInt const&, llvm::APInt const&, llvm::KnownBits&, llvm::TargetLowering::TargetLoweringOpt&, unsigned int, bool) const TargetLowering.cpp:0:0
#14 0x0000559d93a0630e llvm::TargetLowering::SimplifyDemandedBits(llvm::SDValue, llvm::APInt const&, llvm::KnownBits&, llvm::TargetLowering::TargetLoweringOpt&, unsigned int, bool) const TargetLowering.cpp:0:0
#15 0x0000559d93a0617c llvm::TargetLowering::SimplifyDemandedBits(llvm::SDValue, llvm::APInt const&, llvm::TargetLowering::DAGCombinerInfo&) const TargetLowering.cpp:0:0
#16 0x0000559d92fa9653 combineMOVMSK(llvm::SDNode*, llvm::SelectionDAG&, llvm::TargetLowering::DAGCombinerInfo&, llvm::X86Subtarget const&) X86ISelLowering.cpp:0:0
#17 0x0000559d92f781d3 llvm::X86TargetLowering::PerformDAGCombine(llvm::SDNode*, llvm::TargetLowering::DAGCombinerInfo&) const X86ISelLowering.cpp:0:0
#18 0x0000559d937b576b (anonymous namespace)::DAGCombiner::combine(llvm::SDNode*) DAGCombiner.cpp:0:0
#19 0x0000559d937b43ad llvm::SelectionDAG::Combine(llvm::CombineLevel, llvm::AAResults*, llvm::CodeGenOptLevel) DAGCombiner.cpp:0:0
#20 0x0000559d939354ac llvm::SelectionDAGISel::CodeGenAndEmitDAG() SelectionDAGISel.cpp:0:0
#21 0x0000559d93934e45 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) SelectionDAGISel.cpp:0:0
#22 0x0000559d93932d6a llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) SelectionDAGISel.cpp:0:0
#23 0x0000559d93931641 llvm::SelectionDAGISelLegacy::runOnMachineFunction(llvm::MachineFunction&) SelectionDAGISel.cpp:0:0
#24 0x0000559d93616873 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) MachineFunctionPass.cpp:0:0
#25 0x0000559d945f3775 llvm::FPPassManager::runOnFunction(llvm::Function&) LegacyPassManager.cpp:0:0
#26 0x0000559d945fa504 llvm::FPPassManager::runOnModule(llvm::Module&) LegacyPassManager.cpp:0:0
#27 0x0000559d945f4411 llvm::legacy::PassManagerImpl::run(llvm::Module&) LegacyPassManager.cpp:0:0
#28 0x0000559d91d369bc void llvm::detail::UniqueFunctionBase<void>::CallImpl<compileOptimizedLLVMModuleToObject(M::KGEN::LLVMModuleAndContext, mlir::Location, llvm::TargetMachine&, std::mutex&, M::AsyncRT::Runtime&, bool, bool, M::KGEN::CompilationOptions, M::RCRef<M::Cache::BlobCache<M::Cache::TransformCacheKey>>, std::optional<unsigned long>, std::optional<unsigned long>, unsigned int)::$_0>(void*) ObjectCompiler.cpp:0:0
#29 0x0000559d921c2ff1 void (anonymous namespace)::WorkQueueThread::runItemsImpl<(anonymous namespace)::WorkQueueThread::runOnThread()::$_0, (anonymous namespace)::WorkQueueThread::runOnThread()::$_1>((anonymous namespace)::WorkQueueThread::runOnThread()::$_0, (anonymous namespace)::WorkQueueThread::runOnThread()::$_1, bool, llvm::StringLiteral, llvm::StringLiteral) ThreadPoolWorkQueue.cpp:0:0
#30 0x0000559d921c28c7 (anonymous namespace)::WorkQueueThread::runOnThread() ThreadPoolWorkQueue.cpp:0:0
#31 0x00007f6b96fbab65 execute_native_thread_routine /home/conda/feedstock_root/build_artifacts/gcc_compilers_1729025086244/work/build/x86_64-conda-linux-gnu/libstdc++-v3/src/c++11/../../../../../libstdc++-v3/src/c++11/thread.cc:106:5
#32 0x00007f6b96d43148 start_thread (/lib64/libc.so.6+0x71148)
#33 0x00007f6b96dc70cc __GI___clone3 (/lib64/libc.so.6+0xf50cc)
mojo crashed!
Please file a bug report.
zsh: floating point exception (core dumped)  mojo build main.mojo

Steps to reproduce

from memory import bitcast

fn main():
    var x = SIMD[DType.uint8, 8](1)
    var y = bitcast[DType.bool](x)
    print(y)

System information

- Fedora 41 (Workstation)
- `mojo 25.1.0.dev2024122805 (3497ff0b)`
- `magic 0.5.1 - (based on pixi 0.37.0)` 


$ magic info
     Magic version: 0.5.1
System
------------
      Pixi version: 0.37.0
          Platform: linux-64
  Virtual packages: __unix=0=0
                  : __linux=6.12.5=0
                  : __glibc=2.40=0
                  : __cuda=12.4=0
                  : __archspec=1=skylake
         Cache dir: /home/aditya/.cache/rattler/cache
      Auth storage: /home/aditya/.rattler/credentials.json
  Config locations: No config files found

Global
------------
           Bin dir: /home/aditya/.local/share/modular/bin
   Environment dir: /home/aditya/.local/share/modular/envs
      Manifest dir: /home/aditya/.local/share/modular/manifests/pixi-global.toml

[lattner]

@npanchen Looks like an upstream LLVM bug. Could you take a look whenever you get a chance?

[soraros]

I think this is because the bitcast is invalid. xref

from memory import bitcast

fn main():
  print(f(0))

@no_inline
fn f(a: SIMD[DType.uint8, 8]) -> SIMD[DType.bool, 8]:
  return bitcast[DType.bool, 8](a)  # Invalid bitcast: %2 = bitcast <8 x i8> %0 to <8 x i1>

[lattner]

Ah yes, that would do it.

[npanchen]

@npanchen Looks like an upstream LLVM bug. Could you take a look whenever you get a chance?

absolutely. At least we shouldn't crash like that