Extended Description

Find this error while using LLVM with assertion to build linux kernel 4.19 in ChromeOS, attached is a reproduce, run with:
clang -S -O2 -x c foo-6848da.c

This has been seen since asm goto is introduced and kernel 4.19 is using it.

Error:

clang-9: llvm/lib/Transforms/Scalar/SpeculateAroundPHIs.cpp:581: void speculatePHIs(ArrayRef<llvm::PHINode *>, SmallPtrSetImpl<llvm::Instruction *> &, SmallSetVector<llvm::BasicBlock *, 16> &, llvm::DominatorTree &): Assertion `PredBB->getSingleSuccessor() == ParentBB && "We need a non-critical predecessor to speculate into."' failed.
Stack dump:
0. Program arguments: /usr/bin/clang-9 -cc1 -triple x86_64-pc-linux-gnu -S -disable-free -main-file-name foo.ii -mrelocation-model static -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -coverage-notes-file /home/zhizhouy/trunk/src/scripts/Workspace/foo.gcno -resource-dir /usr/lib64/clang/9.0.0 -internal-isystem /usr/local/include -internal-isystem /usr/lib64/clang/9.0.0/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir /home/zhizhouy/trunk/src/scripts/Workspace -ferror-limit 19 -fmessage-length 0 -fobjc-runtime=gcc -fdiagnostics-show-option -fcolor-diagnostics -vectorize-loops -vectorize-slp -faddrsig -o foo.s -x c foo.ii

1. parser at end of file
2. Optimizer
   #​0 0x0000000003ef50f8 llvm::sys::PrintStackTrace(llvm::raw_ostream&) (/usr/bin/clang-9+0x3ef50f8)
   #​1 0x0000000003ef2c30 llvm::sys::RunSignalHandlers() (/usr/bin/clang-9+0x3ef2c30)
   #​2 0x0000000003ef57a8 (/usr/bin/clang-9+0x3ef57a8)
   #​3 0x00007fc3e6eb7540 __restore_rt (/lib64/libpthread.so.0+0x12540)
   #​4 0x00007fc3e5a6fd31 raise (/lib64/libc.so.6+0x35d31)
   #​5 0x00007fc3e5a71a41 abort (/lib64/libc.so.6+0x37a41)
   #​6 0x00007fc3e5a68437 (/lib64/libc.so.6+0x2e437)
   #​7 0x00007fc3e5a684e2 (/lib64/libc.so.6+0x2e4e2)
   #​8 0x0000000004e65361 (/usr/bin/clang-9+0x4e65361)
   #​9 0x0000000004e5fecb llvm::SpeculateAroundPHIsPass::run(llvm::Function&, llvm::AnalysisManagerllvm::Function&) (/usr/bin/clang-9+0x4e5fecb)
   #​10 0x0000000004e3910d (/usr/bin/clang-9+0x4e3910d)
   #​11 0x0000000003888d22 llvm::PassManager<llvm::Function, llvm::AnalysisManagerllvm::Function >::run(llvm::Function&, llvm::AnalysisManagerllvm::Function&) (/usr/bin/clang-9+0x3888d22)
   #​12 0x0000000004e2e92c (/usr/bin/clang-9+0x4e2e92c)
   #​13 0x00000000038875e2 llvm::PassManager<llvm::Module, llvm::AnalysisManagerllvm::Module >::run(llvm::Module&, llvm::AnalysisManagerllvm::Module&) (/usr/bin/clang-9+0x38875e2)
   #​14 0x0000000004e3a62d (/usr/bin/clang-9+0x4e3a62d)
   #​15 0x00000000038875e2 llvm::PassManager<llvm::Module, llvm::AnalysisManagerllvm::Module >::run(llvm::Module&, llvm::AnalysisManagerllvm::Module&) (/usr/bin/clang-9+0x38875e2)
   #​16 0x00000000044b238a (/usr/bin/clang-9+0x44b238a)
   #​17 0x00000000044aaa4a clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::DataLayout const&, llvm::Module*, clang::BackendAction, std::__1::unique_ptr<llvm::raw_pwrite_stream, std::__1::default_deletellvm::raw_pwrite_stream >) (/usr/bin/clang-9+0x44aaa4a)
   #​18 0x00000000047e94d6 (/usr/bin/clang-9+0x47e94d6)
   #​19 0x000000000580b246 clang::ParseAST(clang::Sema&, bool, bool) (/usr/bin/clang-9+0x580b246)
   #​20 0x000000000471f533 clang::FrontendAction::Execute() (/usr/bin/clang-9+0x471f533)
   #​21 0x0000000004693294 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/usr/bin/clang-9+0x4693294)
   #​22 0x00000000047e3b37 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/usr/bin/clang-9+0x47e3b37)
   #​23 0x0000000002a4b1ff cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/usr/bin/clang-9+0x2a4b1ff)
   #​24 0x0000000002a48191 main (/usr/bin/clang-9+0x2a48191)
   #​25 0x00007fc3e5a5ba8e __libc_start_main (/lib64/libc.so.6+0x21a8e)
   #​26 0x0000000002a4502a _start (/usr/bin/clang-9+0x2a4502a)
   clang-9: error: unable to execute command: Aborted
   clang-9: error: clang frontend command failed due to signal (use -v to see invocation)