[AVR] crash in SelectionDAG

[benshi001]

The following C code leads crash

// a.c
void foo(int);
__flash const int *aff1(__flash const int *p) {
        foo(*p);
        return p + 1;
}

Command:

clang a.c -O3 -Wall -S --target=avr -mmcu=atmega328

Crash message:

/usr/include/c++/7/bits/stl_vector.h:797: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) [with _Tp = llvm::SUnit; _Alloc = std::allocator<llvm::SUnit>; std::vector<_Tp, _Alloc>::reference = llvm::SUnit&; std::vector<_Tp, _Alloc>::size_type = long unsigned int]: Assertion '__builtin_expect(__n < this->size(), true)' 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: ./bin/clang a.c -O3 -Wall -S --target=avr -mmcu=atmega328
1.      <eof> parser at end of file
2.      Code generation
3.      Running pass 'Function Pass Manager' on module 'a.c'.
4.      Running pass 'AVR DAG->DAG Instruction Selection' on function '@aff1'
 #0 0x000055fe55588aaa llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (./bin/clang+0x2171aaa)
 #1 0x000055fe5558677c llvm::sys::CleanupOnSignal(unsigned long) (./bin/clang+0x216f77c)
 #2 0x000055fe554e4ee8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007f9b3236b420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #4 0x00007f9b31e0800b raise /build/glibc-SzIz7B/glibc-2.31/signal/../sysdeps/unix/sysv/linux/raise.c:51:1
 #5 0x00007f9b31de7859 abort /build/glibc-SzIz7B/glibc-2.31/stdlib/abort.c:81:7
 #6 0x000055fe54229b82 (./bin/clang+0xe12b82)
 #7 0x000055fe565ad63f llvm::ScheduleDAGSDNodes::AddSchedEdges() (./bin/clang+0x319663f)
 #8 0x000055fe565a8aba (anonymous namespace)::ScheduleDAGRRList::Schedule() ScheduleDAGRRList.cpp:0:0
 #9 0x000055fe564ed17a llvm::SelectionDAGISel::CodeGenAndEmitDAG() (./bin/clang+0x30d617a)
#10 0x000055fe564f0219 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (./bin/clang+0x30d9219)
#11 0x000055fe564f22be llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (.part.971) SelectionDAGISel.cpp:0:0
#12 0x000055fe54971bd2 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.72) MachineFunctionPass.cpp:0:0
#13 0x000055fe54eb42a6 llvm::FPPassManager::runOnFunction(llvm::Function&) (./bin/clang+0x1a9d2a6)
#14 0x000055fe54eb4531 llvm::FPPassManager::runOnModule(llvm::Module&) (./bin/clang+0x1a9d531)
#15 0x000055fe54eb4fc2 llvm::legacy::PassManagerImpl::run(llvm::Module&) (./bin/clang+0x1a9dfc2)
#16 0x000055fe5590bf06 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>>) (./bin/clang+0x24f4f06)
#17 0x000055fe566218c9 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) crtstuff.c:0:0
#18 0x000055fe57327359 clang::ParseAST(clang::Sema&, bool, bool) (./bin/clang+0x3f10359)
#19 0x000055fe5662241d clang::CodeGenAction::ExecuteAction() (./bin/clang+0x320b41d)
#20 0x000055fe560056a1 clang::FrontendAction::Execute() (./bin/clang+0x2bee6a1)
#21 0x000055fe55f98fea clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (./bin/clang+0x2b81fea)
#22 0x000055fe560db047 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (./bin/clang+0x2cc4047)
#23 0x000055fe5423323c cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (./bin/clang+0xe1c23c)
#24 0x000055fe5422e1bf ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#25 0x000055fe55e1d015 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#26 0x000055fe554e5673 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (./bin/clang+0x20ce673)
#27 0x000055fe55e1f948 clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (./bin/clang+0x2a08948)
#28 0x000055fe55dee7eb clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (./bin/clang+0x29d77eb)
#29 0x000055fe55def343 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (./bin/clang+0x29d8343)
#30 0x000055fe55df61d9 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (./bin/clang+0x29df1d9)
#31 0x000055fe54230ebd clang_main(int, char**) (./bin/clang+0xe19ebd)
#32 0x00007f9b31de9083 __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:342:3
#33 0x000055fe5422917e _start (./bin/clang+0xe1217e)
clang-16: error: clang frontend command failed with exit code 134 (use -v to see invocation)
clang version 16.0.0 (git@github.com:llvm/llvm-project.git e4a7b328205e791e9eeafa85f0b19e6d062fe8cc)
Target: avr
Thread model: posix
InstalledDir: /home/benshi/work/llvm-project/build/./bin
clang-16: note: diagnostic msg:
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-16: note: diagnostic msg: /tmp/a-7d51fa.c
clang-16: note: diagnostic msg: /tmp/a-7d51fa.sh
clang-16: note: diagnostic msg:

********************

[benshi001]

I find a workaround, if we always return false in bool AVRTargetLowering::getPostIndexedAddressParts(...), then this crash is suppressed.