[X86][GISel] fatal error: error in backend: Cannot emit physreg copy instruction #166557
Description
Reproducer:
https://godbolt.org/z/6PW8fnTP1
union foo {
_Float16 foo;
short s;
};
_Float16 bar(union foo x) { return x.foo; }Backtrace:
fatal error: error in backend: Cannot emit physreg copy instruction
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: /opt/compiler-explorer/clang-trunk/bin/clang++ -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -mllvm -global-isel <source>
1. <eof> parser at end of file
2. Code generation
3. Running pass 'Function Pass Manager' on module '<source>'.
4. Running pass 'Post-RA pseudo instruction expansion pass' on function '@_Z3bar3foo'
#0 0x0000000003d11b38 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3d11b38)
#1 0x0000000003d0f50c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3d0f50c)
#2 0x0000000003c557b3 llvm::CrashRecoveryContext::HandleExit(int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c557b3)
#3 0x0000000003d06d4e llvm::sys::Process::Exit(int, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3d06d4e)
#4 0x0000000000dda51b LLVMErrorHandler(void*, char const*, bool) cc1_main.cpp:0:0
#5 0x0000000003c5fa13 llvm::report_fatal_error(llvm::Twine const&, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c5fa13)
#6 0x0000000003c5fb78 (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c5fb78)
#7 0x00000000029d9b8c llvm::X86InstrInfo::copyPhysReg(llvm::MachineBasicBlock&, llvm::MachineInstrBundleIterator<llvm::MachineInstr, false>, llvm::DebugLoc const&, llvm::Register, llvm::Register, bool, bool, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x29d9b8c)
#8 0x00000000033765c4 llvm::TargetInstrInfo::lowerCopy(llvm::MachineInstr*, llvm::TargetRegisterInfo const*) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x33765c4)
#9 0x0000000002fcf8b8 (anonymous namespace)::ExpandPostRA::run(llvm::MachineFunction&) (.constprop.0) ExpandPostRAPseudos.cpp:0:0
#10 0x0000000002fcfad4 (anonymous namespace)::ExpandPostRALegacy::runOnMachineFunction(llvm::MachineFunction&) ExpandPostRAPseudos.cpp:0:0
#11 0x00000000030ef0dd llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x30ef0dd)
#12 0x0000000003663302 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3663302)
#13 0x0000000003663591 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3663591)
#14 0x0000000003664e73 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3664e73)
#15 0x0000000003fae042 clang::emitBackendOutput(clang::CompilerInstance&, clang::CodeGenOptions&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3fae042)
#16 0x00000000045e5ccb clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x45e5ccb)
#17 0x000000000625ba5c clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x625ba5c)
#18 0x00000000045e6825 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x45e6825)
#19 0x00000000048e4c2a clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x48e4c2a)
#20 0x000000000486496b clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x486496b)
#21 0x00000000049dcdfb clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x49dcdfb)
#22 0x0000000000ddc575 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xddc575)
#23 0x0000000000dd44db ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) driver.cpp:0:0
#24 0x0000000000dd457d int llvm::function_ref<int (llvm::SmallVectorImpl<char const*>&)>::callback_fn<clang_main(int, char**, llvm::ToolContext const&)::'lambda'(llvm::SmallVectorImpl<char const*>&)>(long, llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#25 0x0000000004654899 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 0x0000000003c556b3 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c556b3)
#27 0x0000000004654ab9 clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#28 0x0000000004617682 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4617682)
#29 0x0000000004618561 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4618561)
#30 0x000000000462140c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x462140c)
#31 0x0000000000dd8fa9 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdd8fa9)
#32 0x0000000000c83ec4 main (/opt/compiler-explorer/clang-trunk/bin/clang+++0xc83ec4)
#33 0x000071721c829d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#34 0x000071721c829e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#35 0x0000000000dd3f75 _start (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdd3f75)
clang++: error: clang frontend command failed with exit code 70 (use -v to see invocation)
Compiler returned: 70