[SimplifyCFG] clang crashes at -O1, -Os & -O2 on x86_64-linux-gnu: Assertion `IterCnt++ < 1000 && "Iterative simplification didn't converge!"' failed #56203
Description
It appears to be a regression from 14.0.0.
% clangtk -v
clang version 15.0.0 (https://github.com/llvm/llvm-project.git 874fbe2cbbe6f548858d0c8e804eb66ca477697c)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /local/suz-local/opfuzz/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Candidate multilib: .;@m64
Selected multilib: .;@m64
Found CUDA installation: /usr/local/cuda, version 11.0
%
% clangtk -O1 small.c
clang-15: /local/suz-local/software/clangbuild/llvm-project/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp:240: bool iterativelySimplifyCFG(llvm::Function&, const llvm::TargetTransformInfo&, llvm::DomTreeUpdater*, const llvm::SimplifyCFGOptions&): Assertion `IterCnt++ < 1000 && "Iterative simplification didn't converge!"' 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: /local/suz-local/software/local/clang-trunk/bin/clang-15 -cc1 -triple x86_64-unknown-linux-gnu -emit-obj --mrelax-relocations -disable-free -clear-ast-before-backend -main-file-name small.c -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -mllvm -treat-scalable-fixed-error-as-warning -debugger-tuning=gdb -fcoverage-compilation-dir=/local/suz-local/software/emitesting/bugs/20220624-clangtk-m64-O1-build-163908/delta -resource-dir /local/suz-local/software/local/clang-trunk/lib/clang/15.0.0 -I /usr/local/include/csmith -I /local/suz-local/software/local/include -internal-isystem /local/suz-local/software/local/clang-trunk/lib/clang/15.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O1 -fdebug-compilation-dir=/local/suz-local/software/emitesting/bugs/20220624-clangtk-m64-O1-build-163908/delta -ferror-limit 19 -fgnuc-version=4.2.1 -fcolor-diagnostics -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/small-b8f557.o -x c small.c
1. <eof> parser at end of file
2. Optimizer
#0 0x000056130d2b255f PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
#1 0x000056130d2aff8c SignalHandler(int) Signals.cpp:0:0
#2 0x00007f99af4b1980 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x12980)
#3 0x00007f99ae162e87 raise /build/glibc-uZu3wS/glibc-2.27/signal/../sysdeps/unix/sysv/linux/raise.c:51:0
#4 0x00007f99ae1647f1 abort /build/glibc-uZu3wS/glibc-2.27/stdlib/abort.c:81:0
#5 0x00007f99ae1543fa __assert_fail_base /build/glibc-uZu3wS/glibc-2.27/assert/assert.c:89:0
#6 0x00007f99ae154472 (/lib/x86_64-linux-gnu/libc.so.6+0x30472)
#7 0x000056130d18460e iterativelySimplifyCFG(llvm::Function&, llvm::TargetTransformInfo const&, llvm::DomTreeUpdater*, llvm::SimplifyCFGOptions const&) SimplifyCFGPass.cpp:0:0
#8 0x000056130d18577a simplifyFunctionCFGImpl(llvm::Function&, llvm::TargetTransformInfo const&, llvm::DominatorTree*, llvm::SimplifyCFGOptions const&) SimplifyCFGPass.cpp:0:0
#9 0x000056130d1872c2 llvm::SimplifyCFGPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3a492c2)
#10 0x000056130b469541 llvm::detail::PassModel<llvm::Function, llvm::SimplifyCFGPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x1d2b541)
#11 0x000056130ca44fba llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3306fba)
#12 0x000056130addaac1 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>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x169cac1)
#13 0x000056130c0f6bab llvm::CGSCCToFunctionPassAdaptor::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x29b8bab)
#14 0x000056130addb7f1 llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::CGSCCToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x169d7f1)
#15 0x000056130c0ef5f3 llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x29b15f3)
#16 0x000056130cb73861 llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3435861)
#17 0x000056130c0f2b20 llvm::DevirtSCCRepeatedPass::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x29b4b20)
#18 0x000056130cb73821 llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::DevirtSCCRepeatedPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3435821)
#19 0x000056130c0f10ff llvm::ModuleToPostOrderCGSCCPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x29b30ff)
#20 0x000056130cb738e1 llvm::detail::PassModel<llvm::Module, llvm::ModuleToPostOrderCGSCCPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x34358e1)
#21 0x000056130ca432f4 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x33052f4)
#22 0x000056130cb7836e llvm::ModuleInlinerWrapperPass::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x343a36e)
#23 0x000056130e3f6321 llvm::detail::PassModel<llvm::Module, llvm::ModuleInlinerWrapperPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x4cb8321)
#24 0x000056130ca432f4 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x33052f4)
#25 0x000056130d623f7f (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>>&) (.constprop.782) BackendUtil.cpp:0:0
#26 0x000056130d626e80 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>>) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3ee8e80)
#27 0x000056130e387fdb clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x4c49fdb)
#28 0x000056130eff6789 clang::ParseAST(clang::Sema&, bool, bool) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x58b8789)
#29 0x000056130e386ca0 clang::CodeGenAction::ExecuteAction() (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x4c48ca0)
#30 0x000056130dcfabf9 clang::FrontendAction::Execute() (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x45bcbf9)
#31 0x000056130dc94a6a clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x4556a6a)
#32 0x000056130ddc83a3 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x468a3a3)
#33 0x000056130ab00681 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x13c2681)
#34 0x000056130aaf9809 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#35 0x000056130aafc72f clang_main(int, char**) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x13be72f)
#36 0x00007f99ae145c87 __libc_start_main /build/glibc-uZu3wS/glibc-2.27/csu/../csu/libc-start.c:344:0
#37 0x000056130aaf907a _start (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x13bb07a)
clang-15: error: unable to execute command: Aborted
clang-15: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 15.0.0 (https://github.com/llvm/llvm-project.git 874fbe2cbbe6f548858d0c8e804eb66ca477697c)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /local/suz-local/opfuzz/bin
clang-15: note: diagnostic msg:
********************
PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-15: note: diagnostic msg: /tmp/small-a1555b.c
clang-15: note: diagnostic msg: /tmp/small-a1555b.sh
clang-15: note: diagnostic msg:
********************
%
% cat small.c
int printf(const char *, ...);
long a, b;
volatile long c;
int main() {
int d = 1;
a = (b && (d = a >= -1)) > 0 && d;
if (d <= 0) {
c;
while (b)
if (d)
printf("0");
}
return 0;
}Compiler Explorer: https://godbolt.org/z/8cKcMqzKv