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An assertion failure in TurnSwitchRangeIntoICmp #53208

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kazutakahirata opened this issue Jan 14, 2022 · 1 comment
Closed

An assertion failure in TurnSwitchRangeIntoICmp #53208

kazutakahirata opened this issue Jan 14, 2022 · 1 comment
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llvm:crash llvm:optimizations

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@kazutakahirata
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The following test case triggers an assertion failure in TurnSwitchRangeIntoICmp.

For the assertion failure to occur, we must have null PHI arguments and nonnull dereferenceable(4). I don't know how valid this combination is. The test case comes from the LLVM source code compiled with AutoFDO+ThinLTO. Presumably, some inlining is partly responsible for creating this strange combination because the crash does not occur with the baseline build without AutoFDO or ThinLTO.

$ reduced.ll
define void @0(i8 %sw, i32* %p0) {
  switch i8 %sw, label %group3 [
    i8 0, label %group1
    i8 1, label %group1
    i8 2, label %group1
    i8 3, label %group1
    i8 11, label %group1
    i8 12, label %group1
    i8 13, label %group1
    i8 7, label %group1
    i8 17, label %group1
    i8 14, label %group1
    i8 15, label %group1
    i8 4, label %group2
    i8 5, label %group2
    i8 6, label %group2
    i8 8, label %group2
    i8 9, label %group2
    i8 10, label %group2
  ]

group1:
  br label %exit

group2:
  br label %exit

group3:
  br label %exit

exit:
  %phi = phi i32* [ null, %group3 ], [ %p0, %group2 ], [ null, %group1 ]
  call void @bar(i32* %phi)
  ret void
}

declare void @bar(i32* nonnull dereferenceable(4))
$ ~/rel/bin/clang -O1 -c reduced.ll
warning: overriding the module target triple with x86_64-unknown-linux-gnu [-Woverride-module]
clang: /home/kazu/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:4850: bool (anonymous namespace)::SimplifyCFGOpt::TurnSwitchRangeIntoICmp(llvm::SwitchInst *, IRBuilder<> &): Assertion `DestA && DestB && "Single-destination switch should have been folded."' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: /home/kazu/rel/bin/clang -O1 -c reduced.ll
1.	Optimizer
 #0 0x00007fdd94cfcb73 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/kazu/rel/bin/../lib/libLLVMSupport.so.14git+0x1b6b73)
 #1 0x00007fdd94cfa94e llvm::sys::RunSignalHandlers() (/home/kazu/rel/bin/../lib/libLLVMSupport.so.14git+0x1b494e)
 #2 0x00007fdd94c18ef3 (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) CrashRecoveryContext.cpp:0:0
 #3 0x00007fdd94c1909e CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #4 0x00007fdd98a43200 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x13200)
 #5 0x00007fdd94650891 raise ./signal/../sysdeps/unix/sysv/linux/raise.c:50:1
 #6 0x00007fdd9463a536 abort ./stdlib/abort.c:81:7
 #7 0x00007fdd9463a41f get_sysdep_segment_value ./intl/loadmsgcat.c:509:8
 #8 0x00007fdd9463a41f _nl_load_domain ./intl/loadmsgcat.c:970:34
 #9 0x00007fdd94649212 (/lib/x86_64-linux-gnu/libc.so.6+0x35212)
#10 0x00007fdd963c7d66 (anonymous namespace)::SimplifyCFGOpt::simplifySwitch(llvm::SwitchInst*, llvm::IRBuilder<llvm::ConstantFolder, llvm::IRBuilderDefaultInserter>&) SimplifyCFG.cpp:0:0
#11 0x00007fdd963b98d6 (anonymous namespace)::SimplifyCFGOpt::run(llvm::BasicBlock*) SimplifyCFG.cpp:0:0
#12 0x00007fdd963b8554 llvm::simplifyCFG(llvm::BasicBlock*, llvm::TargetTransformInfo const&, llvm::DomTreeUpdater*, llvm::SimplifyCFGOptions const&, llvm::ArrayRef<llvm::WeakVH>) (/home/kazu/rel/bin/../lib/libLLVMTransformUtils.so.14git+0x1be554)
#13 0x00007fdd969d20ea iterativelySimplifyCFG(llvm::Function&, llvm::TargetTransformInfo const&, llvm::DomTreeUpdater*, llvm::SimplifyCFGOptions const&) SimplifyCFGPass.cpp:0:0
#14 0x00007fdd969d1b10 simplifyFunctionCFGImpl(llvm::Function&, llvm::TargetTransformInfo const&, llvm::DominatorTree*, llvm::SimplifyCFGOptions const&) SimplifyCFGPass.cpp:0:0
#15 0x00007fdd969d06cd simplifyFunctionCFG(llvm::Function&, llvm::TargetTransformInfo const&, llvm::DominatorTree*, llvm::SimplifyCFGOptions const&) SimplifyCFGPass.cpp:0:0
#16 0x00007fdd969d043e llvm::SimplifyCFGPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/kazu/rel/bin/../lib/libLLVMScalarOpts.so.14git+0x33943e)
#17 0x00007fdd9372917d llvm::detail::PassModel<llvm::Function, llvm::SimplifyCFGPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/kazu/rel/bin/../lib/../lib/libLLVMPasses.so.14git+0x10717d)
#18 0x00007fdd957b83e1 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/kazu/rel/bin/../lib/libLLVMCore.so.14git+0x2863e1)
#19 0x00007fdd9835fc2d 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>&) (/home/kazu/rel/bin/../lib/libclangCodeGen.so.14git+0xe7c2d)
#20 0x00007fdd957bd07b llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/kazu/rel/bin/../lib/libLLVMCore.so.14git+0x28b07b)
#21 0x00007fdd98361d2d llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/kazu/rel/bin/../lib/libclangCodeGen.so.14git+0xe9d2d)
#22 0x00007fdd957b6e24 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/kazu/rel/bin/../lib/libLLVMCore.so.14git+0x284e24)
#23 0x00007fdd98359e61 (anonymous namespace)::EmitAssemblyHelper::RunOptimizationPipeline(clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream> >&, std::unique_ptr<llvm::ToolOutputFile, std::default_delete<llvm::ToolOutputFile> >&) BackendUtil.cpp:0:0
#24 0x00007fdd9834da55 clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream> >) (/home/kazu/rel/bin/../lib/libclangCodeGen.so.14git+0xd5a55)
#25 0x00007fdd986e8e7e clang::CodeGenAction::ExecuteAction() (/home/kazu/rel/bin/../lib/libclangCodeGen.so.14git+0x470e7e)
#26 0x00007fdd971d1030 clang::FrontendAction::Execute() (/home/kazu/rel/bin/../lib/libclangFrontend.so.14git+0x13c030)
#27 0x00007fdd9714297f clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/kazu/rel/bin/../lib/libclangFrontend.so.14git+0xad97f)
#28 0x00007fdd98a2b4a3 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/kazu/rel/bin/../lib/libclangFrontendTool.so.14git+0x44a3)
#29 0x0000000000413841 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/kazu/rel/bin/clang+0x413841)
#30 0x0000000000411240 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#31 0x00007fdd96e8d1c2 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, bool*) const::$_1>(long) Job.cpp:0:0
#32 0x00007fdd94c18e07 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/kazu/rel/bin/../lib/libLLVMSupport.so.14git+0xd2e07)
#33 0x00007fdd96e8cc00 clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, bool*) const (/home/kazu/rel/bin/../lib/libclangDriver.so.14git+0xb4c00)
#34 0x00007fdd96e54ee8 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&) const (/home/kazu/rel/bin/../lib/libclangDriver.so.14git+0x7cee8)
#35 0x00007fdd96e551b7 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*> >&) const (/home/kazu/rel/bin/../lib/libclangDriver.so.14git+0x7d1b7)
#36 0x00007fdd96e70171 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*> >&) (/home/kazu/rel/bin/../lib/libclangDriver.so.14git+0x98171)
#37 0x0000000000410811 main (/home/kazu/rel/bin/clang+0x410811)
#38 0x00007fdd9463b7ed __libc_start_main ./csu/../csu/libc-start.c:332:16
#39 0x000000000040e00a _start (/home/kazu/rel/bin/clang+0x40e00a)
clang-14: error: clang frontend command failed with exit code 134 (use -v to see invocation)
clang version 14.0.0 (https://github.com/llvm/llvm-project.git bfd0cbd4eb9fef85da96bb799038ba49a52d08f8)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/kazu/rel/bin
clang-14: note: diagnostic msg: Error generating preprocessed source(s) - no preprocessable inputs.
zmodem pushed a commit that referenced this issue Jun 16, 2022
@saeubank @zmodem
Prevent crash when TurnSwitchRangeIntoICmp receives default unreachab…
bf02ed2 
…le destination

TurnSwitchRangeIntoICmp crashes when given a switch with a default
destination of unreachable
Addresses issue #53208
#53208

Differential revision: https://reviews.llvm.org/D127712
@aeubanks
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Fixed with https://reviews.llvm.org/D127712

mem-frob pushed a commit to draperlaboratory/hope-llvm-project that referenced this issue Oct 7, 2022
@saeubank
Prevent crash when TurnSwitchRangeIntoICmp receives default unreachab…
c79716d 
…le destination

TurnSwitchRangeIntoICmp crashes when given a switch with a default
destination of unreachable
Addresses issue #53208
llvm/llvm-project#53208

Differential revision: https://reviews.llvm.org/D127712
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@fhahn @aeubanks @kazutakahirata