LoopVectorizer assert(AddressSpace == AS && with addrspacecast is hit

[coldav]

The following code produces an assert in RuntimeCheckingPtrGroup::addPointer()

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-elf"

define void @__mux_host_0(ptr addrspace(1) %_arg_resultPtr, ptr addrspace(1) %add.ptr.i.sroa_idx.i.i.i.i) {
loopIR.i.preheader:
  %0 = alloca i8, i64 0, align 128
  %_arg_localAccessor = addrspacecast ptr %0 to ptr addrspace(3)
  %arrayidx.ascast.i.i.i.i.i.i = addrspacecast ptr %0 to ptr addrspace(4)
  br label %loopIR2.i

loopIR2.i:                                        ; preds = %loopIR2.i, %loopIR.i.preheader
  %1 = phi i64 [ 0, %loopIR.i.preheader ], [ %3, %loopIR2.i ]
  store i32 0, ptr addrspace(4) %arrayidx.ascast.i.i.i.i.i.i, align 4
  store float 0.000000e+00, ptr addrspace(1) %add.ptr.i.sroa_idx.i.i.i.i, align 4
  %2 = load i64, ptr addrspace(3) %_arg_localAccessor, align 4
  store i64 0, ptr addrspace(1) %_arg_resultPtr, align 4
  %3 = add i64 %1, 1
  br i1 false, label %loopIR2.i, label %exitIR.i

exitIR.i:                                         ; preds = %loopIR2.i
  ret void
}

This crashes with opt --passes loop-vectorize /tmp/reduced.ll -S -o - as follows:

./bin/opt --passes loop-vectorize /tmp/reduced.ll -S -o -
opt: /home/colin/llvm-project/llvm/lib/Analysis/LoopAccessAnalysis.cpp:423: bool llvm::RuntimeCheckingPtrGroup::addPointer(unsigned int, const llvm::SCEV*, const llvm::SCEV*, unsigned int, bool, llvm::ScalarEvolution&): Assertion `AddressSpace == AS && "all pointers in a checking group must be in the same address space"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: ./bin/opt --passes loop-vectorize /tmp/reduced.ll -S -o -
1.      Running pass "function(loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>)" on module "/tmp/reduced.ll"
2.      Running pass "loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>" on function "__mux_host_0"
 #0 0x00005a58a99c2ddc llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/colin/llvm-project/llvm/lib/Support/Unix/Signals.inc:798:22
 #1 0x00005a58a99c31fd PrintStackTraceSignalHandler(void*) /home/colin/llvm-project/llvm/lib/Support/Unix/Signals.inc:874:1
 #2 0x00005a58a99c0663 llvm::sys::RunSignalHandlers() /home/colin/llvm-project/llvm/lib/Support/Signals.cpp:105:20
 #3 0x00005a58a99c2674 SignalHandler(int) /home/colin/llvm-project/llvm/lib/Support/Unix/Signals.inc:415:1
 #4 0x00007c96b3242520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #5 0x00007c96b32969fc __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 #6 0x00007c96b32969fc __pthread_kill_internal ./nptl/pthread_kill.c:78:10
 #7 0x00007c96b32969fc pthread_kill ./nptl/pthread_kill.c:89:10
 #8 0x00007c96b3242476 gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #9 0x00007c96b32287f3 abort ./stdlib/abort.c:81:7
#10 0x00007c96b322871b _nl_load_domain ./intl/loadmsgcat.c:1177:9
#11 0x00007c96b3239e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#12 0x00005a58a8936a8b llvm::RuntimeCheckingPtrGroup::addPointer(unsigned int, llvm::SCEV const*, llvm::SCEV const*, unsigned int, bool, llvm::ScalarEvolution&) /home/colin/llvm-project/llvm/lib/Analysis/LoopAccessAnalysis.cpp:429:37
#13 0x00005a58a8936a20 llvm::RuntimeCheckingPtrGroup::addPointer(unsigned int, llvm::RuntimePointerChecking const&) /home/colin/llvm-project/llvm/lib/Analysis/LoopAccessAnalysis.cpp:413:20
#14 0x00005a58a8936f8d llvm::RuntimePointerChecking::groupChecks(llvm::EquivalenceClasses<llvm::PointerIntPair<llvm::Value*, 1u, bool, llvm::PointerLikeTypeTraits<llvm::Value*>, llvm::PointerIntPairInfo<llvm::Value*, 1u, llvm::PointerLikeTypeTraits<llvm::Value*>>>, std::less<llvm::PointerIntPair<llvm::Value*, 1u, bool, llvm::PointerLikeTypeTraits<llvm::Value*>, llvm::PointerIntPairInfo<llvm::Value*, 1u, llvm::PointerLikeTypeTraits<llvm::Value*>>>>>&, bool) /home/colin/llvm-project/llvm/lib/Analysis/LoopAccessAnalysis.cpp:554:11
#15 0x00005a58a893678d llvm::RuntimePointerChecking::generateChecks(llvm::EquivalenceClasses<llvm::PointerIntPair<llvm::Value*, 1u, bool, llvm::PointerLikeTypeTraits<llvm::Value*>, llvm::PointerIntPairInfo<llvm::Value*, 1u, llvm::PointerLikeTypeTraits<llvm::Value*>>>, std::less<llvm::PointerIntPair<llvm::Value*, 1u, bool, llvm::PointerLikeTypeTraits<llvm::Value*>, llvm::PointerIntPairInfo<llvm::Value*, 1u, llvm::PointerLikeTypeTraits<llvm::Value*>>>>>&, bool) /home/colin/llvm-project/llvm/lib/Analysis/LoopAccessAnalysis.cpp:389:26
#16 0x00005a58a893a016 (anonymous namespace)::AccessAnalysis::canCheckPtrAtRT(llvm::RuntimePointerChecking&, llvm::ScalarEvolution*, llvm::Loop*, llvm::DenseMap<llvm::Value*, llvm::SCEV const*, llvm::DenseMapInfo<llvm::Value*, void>, llvm::detail::DenseMapPair<llvm::Value*, llvm::SCEV const*>> const&, llvm::Value*&, bool) /home/colin/llvm-project/llvm/lib/Analysis/LoopAccessAnalysis.cpp:1243:3
#17 0x00005a58a8940750 llvm::LoopAccessInfo::analyzeLoop(llvm::AAResults*, llvm::LoopInfo const*, llvm::TargetLibraryInfo const*, llvm::DominatorTree*) /home/colin/llvm-project/llvm/lib/Analysis/LoopAccessAnalysis.cpp:2638:31
#18 0x00005a58a89422b3 llvm::LoopAccessInfo::LoopAccessInfo(llvm::Loop*, llvm::ScalarEvolution*, llvm::TargetTransformInfo const*, llvm::TargetLibraryInfo const*, llvm::AAResults*, llvm::DominatorTree*, llvm::LoopInfo*) /home/colin/llvm-project/llvm/lib/Analysis/LoopAccessAnalysis.cpp:3028:15
#19 0x00005a58a894ae40 std::_MakeUniq<llvm::LoopAccessInfo>::__single_object std::make_unique<llvm::LoopAccessInfo, llvm::Loop*, llvm::ScalarEvolution*, llvm::TargetTransformInfo*&, llvm::TargetLibraryInfo const*&, llvm::AAResults*, llvm::DominatorTree*, llvm::LoopInfo*>(llvm::Loop*&&, llvm::ScalarEvolution*&&, llvm::TargetTransformInfo*&, llvm::TargetLibraryInfo const*&, llvm::AAResults*&&, llvm::DominatorTree*&&, llvm::LoopInfo*&&) /usr/include/c++/11/bits/unique_ptr.h:962:30
#20 0x00005a58a8942883 llvm::LoopAccessInfoManager::getInfo(llvm::Loop&) /home/colin/llvm-project/llvm/lib/Analysis/LoopAccessAnalysis.cpp:3084:41
#21 0x00005a58a831900e llvm::LoopVectorizationLegality::canVectorizeMemory() /home/colin/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp:1208:7
#22 0x00005a58a831bc45 llvm::LoopVectorizationLegality::canVectorize(bool) /home/colin/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp:1840:7
#23 0x00005a58a800b8b5 llvm::LoopVectorizePass::processLoop(llvm::Loop*) /home/colin/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10349:7
#24 0x00005a58a800dde6 llvm::LoopVectorizePass::runImpl(llvm::Function&) /home/colin/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10779:27
#25 0x00005a58a800e133 llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) /home/colin/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10816:39
#26 0x00005a58a65ef71b llvm::detail::PassModel<llvm::Function, llvm::LoopVectorizePass, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) /home/colin/llvm-project/llvm/include/llvm/IR/PassManagerInternal.h:92:3
#27 0x00005a58a96e6133 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) /home/colin/llvm-project/llvm/include/llvm/IR/PassManagerImpl.h:85:18
#28 0x00005a58a4a21a65 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) /home/colin/llvm-project/llvm/include/llvm/IR/PassManagerInternal.h:92:3
#29 0x00005a58a96e513e llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) /home/colin/llvm-project/llvm/lib/IR/PassManager.cpp:129:23
#30 0x00005a58a4a21995 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) /home/colin/llvm-project/llvm/include/llvm/IR/PassManagerInternal.h:92:3
#31 0x00005a58a96e5d5f llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) /home/colin/llvm-project/llvm/include/llvm/IR/PassManagerImpl.h:85:18
#32 0x00005a58a476e632 llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::PassPlugin>, llvm::ArrayRef<std::function<void (llvm::PassBuilder&)>>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool) /home/colin/llvm-project/llvm/tools/opt/NewPMDriver.cpp:541:10
#33 0x00005a58a473c69f optMain /home/colin/llvm-project/llvm/tools/opt/optdriver.cpp:739:27
#34 0x00005a58a4739e81 main /home/colin/llvm-project/llvm/tools/opt/opt.cpp:25:64
#35 0x00007c96b3229d90 __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:58:16
#36 0x00007c96b3229e40 call_init ./csu/../csu/libc-start.c:128:20
#37 0x00007c96b3229e40 __libc_start_main ./csu/../csu/libc-start.c:379:5
#38 0x00005a58a4739d65 _start (./bin/opt+0xb93d65)

I've done some debugging and in RuntimeCheckingPtrGroup::addPointer() II can see the first two elements if RTCheck have the same dependency set but different address spaces.

I did try removing the dependency set being equal continuing the loop here https://github.com/llvm/llvm-project/blob/main/llvm/lib/Analysis/LoopAccessAnalysis.cpp#L1219

      // Only need to check pointers between two different dependency sets.
      if (RtCheck.Pointers[i].DependencySetId ==
          RtCheck.Pointers[j].DependencySetId)
       continue;

This does seem to fix the issue but I was wary on whether this was just another symptom rather than the proper fix.