[clang] ICE in X86 DAG->DAG Instruction Selection when processing inline assembly with invalid ARM SVE instruction #169878
Description
Link for quick verification: https://godbolt.org/z/c1MP8xf8r
When I use ARM SVE instructions in x86 inline assembly with potentially unaligned memory, Clang crashes with an internal compiler error (ICE) instead of reporting a diagnostic about the invalid instruction set or the alignment issue.
typedef float __v4sf __attribute__((__vector_size__(16)));
int main() {
unsigned char arr[32] = {0};
__v4sf xvec1;
__asm__("ldff1 %x[x], %[mem]\n"
: [x]"=V"(xvec1)
: [mem]"m"(*((float (*)[4])&arr))
);
return 0;
}The stack dump is:
0. Program arguments: /workspace/install/llvm/build_21.1.4/bin/clang-21 -cc1 -triple x86_64-unknown-linux-gnu -O3 -emit-obj -dumpdir a- -disable-free -clear-ast-before-backend -main-file-name 26975.fuzz -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 -debugger-tuning=gdb -fdebug-compilation-dir=/workspace/exps -fcoverage-compilation-dir=/workspace/exps -resource-dir /workspace/install/llvm/build_21.1.4/lib/clang/21 -internal-isystem /workspace/install/llvm/build_21.1.4/lib/clang/21/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/13/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -ferror-limit 19 -fmessage-length=153 -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -fcolor-diagnostics -vectorize-loops -vectorize-slp -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/26975-1f98f3.o -x c /workspace/exps/featurefuzz/generate_feature_fine_tuning_qwen_4b_choose_3_1_exp/cases/26975.fuzz
1. <eof> parser at end of file
2. Code generation
3. Running pass 'Function Pass Manager' on module '/workspace/exps/featurefuzz/generate_feature_fine_tuning_qwen_4b_choose_3_1_exp/cases/26975.fuzz'.
4. Running pass 'X86 DAG->DAG Instruction Selection' on function '@main'
#0 0x000060651cf5fc2a llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x9691c2a)
#1 0x000060651cf60457 PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
#2 0x000060651cf59f57 llvm::sys::RunSignalHandlers() (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x968bf57)
#3 0x000060651cf5a1c7 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#4 0x000070e90dd7d330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
#5 0x000070e90ddd6b2c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
#6 0x000070e90ddd6b2c __pthread_kill_internal ./nptl/pthread_kill.c:78:10
#7 0x000070e90ddd6b2c pthread_kill ./nptl/pthread_kill.c:89:10
#8 0x000070e90dd7d27e raise ./signal/../sysdeps/posix/raise.c:27:6
#9 0x000070e90dd608ff abort ./stdlib/abort.c:81:7
#10 0x000070e90dd6081b _nl_load_domain ./intl/loadmsgcat.c:1177:9
#11 0x000070e90dd73517 (/lib/x86_64-linux-gnu/libc.so.6+0x3b517)
#12 0x000060651ed67991 llvm::SelectionDAGBuilder::visitInlineAsm(llvm::CallBase const&, llvm::BasicBlock const*) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xb499991)
#13 0x000060651eda938f llvm::SelectionDAGBuilder::visitCall(llvm::CallInst const&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xb4db38f)
#14 0x000060651ed57abd llvm::SelectionDAGBuilder::visit(unsigned int, llvm::User const&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xb489abd)
#15 0x000060651edab238 llvm::SelectionDAGBuilder::visit(llvm::Instruction const&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xb4dd238)
#16 0x000060651ee9796d llvm::SelectionDAGISel::SelectBasicBlock(llvm::ilist_iterator_w_bits<llvm::ilist_detail::node_options<llvm::Instruction, true, false, void, true, llvm::BasicBlock>, false, true>, llvm::ilist_iterator_w_bits<llvm::ilist_detail::node_options<llvm::Instruction, true, false, void, true, llvm::BasicBlock>, false, true>, bool&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xb5c996d)
#17 0x000060651ee9863e llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xb5ca63e)
#18 0x000060651ee9b11e llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xb5cd11e)
#19 0x000060651acbec0c (anonymous namespace)::X86DAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) X86ISelDAGToDAG.cpp:0:0
#20 0x000060651ee8538d llvm::SelectionDAGISelLegacy::runOnMachineFunction(llvm::MachineFunction&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xb5b738d)
#21 0x000060651ba82586 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x81b4586)
#22 0x000060651c47c6a9 llvm::FPPassManager::runOnFunction(llvm::Function&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x8bae6a9)
#23 0x000060651c47ce89 llvm::FPPassManager::runOnModule(llvm::Module&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x8baee89)
#24 0x000060651c47bb77 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x8badb77)
#25 0x000060651c47c469 llvm::legacy::PassManager::run(llvm::Module&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x8bae469)
#26 0x000060651d38b49e 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*) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x9abd49e)
#27 0x000060651dd743a2 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xa4a63a2)
#28 0x000060652043feb5 clang::ParseAST(clang::Sema&, bool, bool) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xcb71eb5)
#29 0x000060651e18792b clang::ASTFrontendAction::ExecuteAction() (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xa8b992b)
#30 0x000060651dd75360 clang::CodeGenAction::ExecuteAction() (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xa4a7360)
#31 0x000060651e18f9cf clang::FrontendAction::Execute() (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xa8c19cf)
#32 0x000060651e0d5f46 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xa807f46)
#33 0x000060651e317f7b clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0xaa49f7b)
#34 0x0000606518086523 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x47b8523)
#35 0x0000606518076c58 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#36 0x000060651807cb28 clang_main(int, char**, llvm::ToolContext const&) (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x47aeb28)
#37 0x0000606517ed7b4a main (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x4609b4a)
#38 0x000070e90dd621ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#39 0x000070e90dd6228b call_init ./csu/../csu/libc-start.c:128:20
#40 0x000070e90dd6228b __libc_start_main ./csu/../csu/libc-start.c:347:5
#41 0x0000606518074f55 _start (/workspace/install/llvm/build_21.1.4/bin/clang-21+0x47a6f55)
clang: error: unable to execute command: Aborted (core dumped)
The Clang version I used:
clang version 21.1.4 (https://github.com/llvm/llvm-project.git 222fc11f2b8f25f6a0f4976272ef1bb7bf49521d)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /workspace/install/llvm/build_21.1.4/bin
Build config: +assertions
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/13
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/13
Candidate multilib: .;@m64
Selected multilib: .;@m64