[loop-reduce] Assertion `L->isRecursivelyLCSSAForm(LAR.DT, LI) && "Loops must remain in LCSSA form!"' failed. #61182
Description
This bug was found by Azul FuzzGen IR test generator.
Run opt with -passes='loop-reduce'
https://godbolt.org/z/7WaE9hWWf
Stack dump:
0. Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/opt -o /app/output.s -S -passes=loop-reduce <source>
#0 0x00005618ab052b0f llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x398fb0f)
#1 0x00005618ab050234 SignalHandler(int) Signals.cpp:0:0
#2 0x00007f6665809420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
#3 0x00007f66652d600b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
#4 0x00007f66652b5859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
#5 0x00007f66652b5729 (/lib/x86_64-linux-gnu/libc.so.6+0x22729)
#6 0x00007f66652c6fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
#7 0x00005618abdff22e void llvm::detail::UniqueFunctionBase<void, llvm::StringRef, llvm::Any>::CallImpl<llvm::FunctionToLoopPassAdaptor::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&)::'lambda'(llvm::StringRef, llvm::Any)>(void*, llvm::StringRef, llvm::Any&) LoopPassManager.cpp:0:0
#8 0x00005618abdff982 bool llvm::PassInstrumentation::runBeforePass<llvm::Loop, llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>>(llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&> const&, llvm::Loop const&) const (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x473c982)
#9 0x00005618abe00251 std::optional<llvm::PreservedAnalyses> llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runSinglePass<llvm::Loop, std::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>>>>(llvm::Loop&, std::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>>>&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&, llvm::PassInstrumentation&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x473d251)
#10 0x00005618abe00766 llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runWithoutLoopNestPasses(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x473d766)
#11 0x00005618abe01b7d llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x473eb7d)
#12 0x00005618abe02de6 llvm::FunctionToLoopPassAdaptor::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x473fde6)
#13 0x00005618ab3b0a16 llvm::detail::PassModel<llvm::Function, llvm::FunctionToLoopPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x3ceda16)
#14 0x00005618a884a7fa llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x11877fa)
#15 0x00005618aa88ea52 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x31cba52)
#16 0x00005618a8830d76 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x116dd76)
#17 0x00005618aa88c65a llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x31c965a)
#18 0x00005618a83b4665 llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::PassPlugin>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0xcf1665)
#19 0x00005618a82caf77 main (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0xc07f77)
#20 0x00007f66652b7083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#21 0x00005618a83a62be _start (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0xce32be)
Compiler returned: 139