Clang ICE on SVE intrinsic

[SadiinsoSnowfall]

brew gist-logs <formula> link OR brew config AND brew doctor output

HOMEBREW_VERSION: 4.3.19
ORIGIN: https://github.com/Homebrew/brew
HEAD: 1f9bd2de89883ec9a59db3eab0f5475bce06d5bc
Last commit: 3 days ago
Core tap JSON: 05 Sep 18:08 UTC
Core cask tap JSON: 05 Sep 18:08 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_MAKE_JOBS: 16
Homebrew Ruby: 3.3.4 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.3.4_1/bin/ruby
CPU: 16-core 64-bit arm_palma
Clang: 16.0.0 build 1600
Git: 2.39.5 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.1-arm64
CLT: 16.0.0.0.1.1723780521
Xcode: N/A
Rosetta 2: false

Verification

• My brew doctor output says Your system is ready to brew. and am still able to reproduce my issue.
• I ran brew update and am still able to reproduce my issue.
• I have resolved all warnings from brew doctor and that did not fix my problem.
• I searched for recent similar issues at https://github.com/Homebrew/homebrew-core/issues?q=is%3Aissue and found no duplicates.

What were you trying to do (and why)?

Compile the following code using the clang I got from homebrew:

#include <arm_sve.h>

void test(svbool_t t, svint32_t a, svint32_t b) {
    svsub_s32_m(t, a, b);
}

The compiler output told me to report the bug here.

What happened (include all command output)?

The compiler ICE'd:

PLEASE submit a bug report to https://github.com/Homebrew/homebrew-core/issues and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: /opt/homebrew/Cellar/llvm/18.1.8/bin/clang-18 -cc1 -triple arm64-apple-macosx15.0.0 -Wundef-prefix=TARGET_OS_ -Werror=undef-prefix -Wdeprecated-objc-isa-usage -Werror=deprecated-objc-isa-usage -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name test.cpp -mrelocation-model pic -pic-level 2 -mframe-pointer=non-leaf -ffp-contract=on -fno-rounding-math -funwind-tables=1 -fcompatibility-qualified-id-block-type-checking -fvisibility-inlines-hidden-static-local-var -fbuiltin-headers-in-system-modules -fdefine-target-os-macros -target-cpu apple-m1 -target-feature +zcm -target-feature +zcz -target-feature +v8a -target-feature +fp-armv8 -target-feature +fullfp16 -target-feature +neon -target-feature +sve -target-abi darwinpcs -mvscale-max=1 -mvscale-min=1 -debugger-tuning=lldb -fdebug-compilation-dir=/tmp -target-linker-version 1053.12 -fcoverage-compilation-dir=/tmp -resource-dir /opt/homebrew/Cellar/llvm/18.1.8/lib/clang/18 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk -internal-isystem /opt/homebrew/opt/llvm/bin/../include/c++/v1 -internal-isystem /Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk/usr/local/include -internal-isystem /opt/homebrew/Cellar/llvm/18.1.8/lib/clang/18/include -internal-externc-isystem /Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk/usr/include -fdeprecated-macro -ferror-limit 19 -stack-protector 1 -fblocks -fencode-extended-block-signature -fregister-global-dtors-with-atexit -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -fcxx-exceptions -fexceptions -fmax-type-align=16 -fcolor-diagnostics -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /var/folders/_c/4w43161s72x8kd5w24cp7vlm0000gn/T/test-4b8a20.o -x c++ test.cpp
1.	<eof> parser at end of file
2.	Code generation
3.	Running pass 'Function Pass Manager' on module 'test.cpp'.
4.	Running pass 'AArch64 Instruction Selection' on function '@_Z4testu10__SVBool_tu11__SVInt32_tS0_'
 #0 0x00000001188c5d60 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libLLVM.dylib+0x4695d60)
 #1 0x00000001188c6134 SignalHandler(int) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libLLVM.dylib+0x4696134)
 #2 0x000000018388c184 (/usr/lib/system/libsystem_platform.dylib+0x180484184)
 #3 0x00000001167c23b8 llvm::AArch64TargetLowering::LowerFormalArguments(llvm::SDValue, unsigned int, bool, llvm::SmallVectorImpl<llvm::ISD::InputArg> const&, llvm::SDLoc const&, llvm::SelectionDAG&, llvm::SmallVectorImpl<llvm::SDValue>&) const (/opt/homebrew/Cellar/llvm/18.1.8/lib/libLLVM.dylib+0x25923b8)
 #4 0x0000000114e3c648 llvm::SelectionDAGISel::LowerArguments(llvm::Function const&) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libLLVM.dylib+0xc0c648)
 #5 0x0000000114ec7af8 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libLLVM.dylib+0xc97af8)
 #6 0x0000000114ec6578 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libLLVM.dylib+0xc96578)
 #7 0x0000000114889054 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libLLVM.dylib+0x659054)
 #8 0x00000001145440e4 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libLLVM.dylib+0x3140e4)
 #9 0x00000001145383ec llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libLLVM.dylib+0x3083ec)
#10 0x000000010816a0cc clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::__1::unique_ptr<llvm::raw_pwrite_stream, std::__1::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libclang-cpp.dylib+0x15960cc)
#11 0x000000010850f644 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libclang-cpp.dylib+0x193b644)
#12 0x0000000106ddf0f8 clang::ParseAST(clang::Sema&, bool, bool) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libclang-cpp.dylib+0x20b0f8)
#13 0x0000000108c70dd4 clang::FrontendAction::Execute() (/opt/homebrew/Cellar/llvm/18.1.8/lib/libclang-cpp.dylib+0x209cdd4)
#14 0x0000000108bf3ad4 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libclang-cpp.dylib+0x201fad4)
#15 0x0000000108cc3c28 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/homebrew/Cellar/llvm/18.1.8/lib/libclang-cpp.dylib+0x20efc28)
#16 0x000000010216eb28 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/homebrew/Cellar/llvm/18.1.8/bin/clang-18+0x100006b28)
#17 0x000000010216d218 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) (/opt/homebrew/Cellar/llvm/18.1.8/bin/clang-18+0x100005218)
#18 0x000000010216bdac clang_main(int, char**, llvm::ToolContext const&) (/opt/homebrew/Cellar/llvm/18.1.8/bin/clang-18+0x100003dac)
#19 0x0000000102178e38 main (/opt/homebrew/Cellar/llvm/18.1.8/bin/clang-18+0x100010e38)
#20 0x00000001834d4274
clang: error: unable to execute command: Segmentation fault: 11
clang: error: clang frontend command failed due to signal (use -v to see invocation)
Homebrew clang version 18.1.8
Target: arm64-apple-darwin24.1.0
Thread model: posix
InstalledDir: /opt/homebrew/opt/llvm/bin

What did you expect to happen?

The compiler not to crash.

Step-by-step reproduction instructions (by running brew commands)

brew install llvm

Put the given code in a .cpp file (for example, test.cpp).

clang -march=armv8-a+sve -msve-vector-bits=128 test.cpp

[Bo98]

Checked Apple Clang and the same happens there so doesn't seem to be specific to Homebrew LLVM.

Apple CPUs do not support SVE AFAIK. I suspect it doesn't crash with a Linux -target. Technically it probably shouldn't ICE at all but I imagine it's not a priority upstream to fix that.

[SadiinsoSnowfall]

Apple CPUs do not support SVE AFAIK.

Indeed, but cross-compiling should (and does) work. I cross-compile for SVE daily on my mac, I just encountered this specific bug today and reduced it to this short snippet.

Do you think it would be best that I report the issue to LLVM directly ?

[fxcoudert]

Given that it happens with at least two different versions of clang, ours and Apple's, it definitely seems like an upstream bug and not a Homebrew-specific issue:

% clang -march=armv8-a+sve -msve-vector-bits=128 a.c 
clang: error: unable to execute command: Trace/BPT trap: 5
clang: error: clang frontend command failed due to signal (use -v to see invocation)
Apple clang version 15.0.0 (clang-1500.3.9.4)
Target: arm64-apple-darwin23.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
clang: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /var/folders/h8/9hx_fyj91053ksgdzb2w03vw0000gp/T/a-73f5bd.c
clang: note: diagnostic msg: /var/folders/h8/9hx_fyj91053ksgdzb2w03vw0000gp/T/a-73f5bd.sh
clang: note: diagnostic msg: Crash backtrace is located in
clang: note: diagnostic msg: /Users/fx/Library/Logs/DiagnosticReports/clang_<YYYY-MM-DD-HHMMSS>_<hostname>.crash
clang: note: diagnostic msg: (choose the .crash file that corresponds to your crash)
clang: note: diagnostic msg: 

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

It's best to report this to Apple, or to llvm directly (or both).