[AArch64] crash on __attribute__((nvptx_kernel))

[k-arrows]

Reproducer:
https://godbolt.org/z/8bc9GPo7h

__attribute__((nvptx_kernel)) void foo(int *ret) {
  *ret = 1;
}

Backtrace:

fatal error: error in backend: unsupported calling convention
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 -fno-verbose-asm -S -target aarch64-linux-gnu --gcc-toolchain=/opt/compiler-explorer/arm64/gcc-12.2.0/aarch64-unknown-linux-gnu --sysroot=/opt/compiler-explorer/arm64/gcc-12.2.0/aarch64-unknown-linux-gnu/aarch64-unknown-linux-gnu/sysroot -fcolor-diagnostics -fno-crash-diagnostics <source>
1.	<eof> parser at end of file
2.	Code generation
3.	Running pass 'Function Pass Manager' on module '<source>'.
4.	Running pass 'IRTranslator' on function '@_Z3fooPi'
 #0 0x0000000003c46448 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c46448)
 #1 0x0000000003c43e1c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c43e1c)
 #2 0x0000000003b94203 llvm::CrashRecoveryContext::HandleExit(int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b94203)
 #3 0x0000000003c3b66e llvm::sys::Process::Exit(int, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c3b66e)
 #4 0x0000000000dbf31b LLVMErrorHandler(void*, char const*, bool) cc1_main.cpp:0:0
 #5 0x0000000003b9df73 llvm::report_fatal_error(llvm::Twine const&, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b9df73)
 #6 0x0000000003b9e176 (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b9e176)
 #7 0x0000000000fcd959 llvm::AArch64TargetLowering::CCAssignFnForCall(unsigned int, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0xfcd959)
 #8 0x0000000000e531af llvm::AArch64CallLowering::lowerFormalArguments(llvm::MachineIRBuilder&, llvm::Function const&, llvm::ArrayRef<llvm::ArrayRef<llvm::Register>>, llvm::FunctionLoweringInfo&) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0xe531af)
 #9 0x0000000004ed6d80 llvm::IRTranslator::runOnMachineFunction(llvm::MachineFunction&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4ed6d80)
#10 0x00000000030540ad llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x30540ad)
#11 0x00000000035abab2 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x35abab2)
#12 0x00000000035abd41 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x35abd41)
#13 0x00000000035ad617 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x35ad617)
#14 0x0000000003ee4e5d 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+++0x3ee4e5d)
#15 0x000000000450d90c clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x450d90c)
#16 0x000000000615f72c clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x615f72c)
#17 0x000000000450e0fd clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x450e0fd)
#18 0x0000000004813b0a clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4813b0a)
#19 0x000000000478dffb clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x478dffb)
#20 0x00000000049080c3 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x49080c3)
#21 0x0000000000dc1375 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdc1375)
#22 0x0000000000db931d ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#23 0x000000000457acf9 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
#24 0x0000000003b94103 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b94103)
#25 0x000000000457af19 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
#26 0x000000000453de7d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x453de7d)
#27 0x000000000453ee31 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+++0x453ee31)
#28 0x000000000454878c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x454878c)
#29 0x0000000000dbdb81 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdbdb81)
#30 0x0000000000c6d0b4 main (/opt/compiler-explorer/clang-trunk/bin/clang+++0xc6d0b4)
#31 0x00007143efc29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#32 0x00007143efc29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#33 0x0000000000db8db5 _start (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdb8db5)
Compiler returned: 1

[llvmbot]

@llvm/issue-subscribers-backend-aarch64

Author: None (k-arrows)

Reproducer: https://godbolt.org/z/8bc9GPo7h ```cpp __attribute__((nvptx_kernel)) void foo(int *ret) { *ret = 1; } ```

Backtrace:

fatal error: error in backend: unsupported calling convention
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 -fno-verbose-asm -S -target aarch64-linux-gnu --gcc-toolchain=/opt/compiler-explorer/arm64/gcc-12.2.0/aarch64-unknown-linux-gnu --sysroot=/opt/compiler-explorer/arm64/gcc-12.2.0/aarch64-unknown-linux-gnu/aarch64-unknown-linux-gnu/sysroot -fcolor-diagnostics -fno-crash-diagnostics <source>
1.	<eof> parser at end of file
2.	Code generation
3.	Running pass 'Function Pass Manager' on module '<source>'.
4.	Running pass 'IRTranslator' on function '@<!-- -->_Z3fooPi'
 #<!-- -->0 0x0000000003c46448 llvm::sys::PrintStackTrace(llvm::raw_ostream&amp;, int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c46448)
 #<!-- -->1 0x0000000003c43e1c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c43e1c)
 #<!-- -->2 0x0000000003b94203 llvm::CrashRecoveryContext::HandleExit(int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b94203)
 #<!-- -->3 0x0000000003c3b66e llvm::sys::Process::Exit(int, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3c3b66e)
 #<!-- -->4 0x0000000000dbf31b LLVMErrorHandler(void*, char const*, bool) cc1_main.cpp:0:0
 #<!-- -->5 0x0000000003b9df73 llvm::report_fatal_error(llvm::Twine const&amp;, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b9df73)
 #<!-- -->6 0x0000000003b9e176 (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b9e176)
 #<!-- -->7 0x0000000000fcd959 llvm::AArch64TargetLowering::CCAssignFnForCall(unsigned int, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0xfcd959)
 #<!-- -->8 0x0000000000e531af llvm::AArch64CallLowering::lowerFormalArguments(llvm::MachineIRBuilder&amp;, llvm::Function const&amp;, llvm::ArrayRef&lt;llvm::ArrayRef&lt;llvm::Register&gt;&gt;, llvm::FunctionLoweringInfo&amp;) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0xe531af)
 #<!-- -->9 0x0000000004ed6d80 llvm::IRTranslator::runOnMachineFunction(llvm::MachineFunction&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4ed6d80)
#<!-- -->10 0x00000000030540ad llvm::MachineFunctionPass::runOnFunction(llvm::Function&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x30540ad)
#<!-- -->11 0x00000000035abab2 llvm::FPPassManager::runOnFunction(llvm::Function&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x35abab2)
#<!-- -->12 0x00000000035abd41 llvm::FPPassManager::runOnModule(llvm::Module&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x35abd41)
#<!-- -->13 0x00000000035ad617 llvm::legacy::PassManagerImpl::run(llvm::Module&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x35ad617)
#<!-- -->14 0x0000000003ee4e5d clang::emitBackendOutput(clang::CompilerInstance&amp;, clang::CodeGenOptions&amp;, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr&lt;llvm::vfs::FileSystem&gt;, std::unique_ptr&lt;llvm::raw_pwrite_stream, std::default_delete&lt;llvm::raw_pwrite_stream&gt;&gt;, clang::BackendConsumer*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3ee4e5d)
#<!-- -->15 0x000000000450d90c clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x450d90c)
#<!-- -->16 0x000000000615f72c clang::ParseAST(clang::Sema&amp;, bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x615f72c)
#<!-- -->17 0x000000000450e0fd clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x450e0fd)
#<!-- -->18 0x0000000004813b0a clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4813b0a)
#<!-- -->19 0x000000000478dffb clang::CompilerInstance::ExecuteAction(clang::FrontendAction&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x478dffb)
#<!-- -->20 0x00000000049080c3 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x49080c3)
#<!-- -->21 0x0000000000dc1375 cc1_main(llvm::ArrayRef&lt;char const*&gt;, char const*, void*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdc1375)
#<!-- -->22 0x0000000000db931d ExecuteCC1Tool(llvm::SmallVectorImpl&lt;char const*&gt;&amp;, llvm::ToolContext const&amp;) driver.cpp:0:0
#<!-- -->23 0x000000000457acf9 void llvm::function_ref&lt;void ()&gt;::callback_fn&lt;clang::driver::CC1Command::Execute(llvm::ArrayRef&lt;std::optional&lt;llvm::StringRef&gt;&gt;, std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt;&gt;*, bool*) const::'lambda'()&gt;(long) Job.cpp:0:0
#<!-- -->24 0x0000000003b94103 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref&lt;void ()&gt;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3b94103)
#<!-- -->25 0x000000000457af19 clang::driver::CC1Command::Execute(llvm::ArrayRef&lt;std::optional&lt;llvm::StringRef&gt;&gt;, std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt;&gt;*, bool*) const (.part.0) Job.cpp:0:0
#<!-- -->26 0x000000000453de7d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&amp;, clang::driver::Command const*&amp;, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x453de7d)
#<!-- -->27 0x000000000453ee31 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&amp;, llvm::SmallVectorImpl&lt;std::pair&lt;int, clang::driver::Command const*&gt;&gt;&amp;, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x453ee31)
#<!-- -->28 0x000000000454878c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&amp;, llvm::SmallVectorImpl&lt;std::pair&lt;int, clang::driver::Command const*&gt;&gt;&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x454878c)
#<!-- -->29 0x0000000000dbdb81 clang_main(int, char**, llvm::ToolContext const&amp;) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdbdb81)
#<!-- -->30 0x0000000000c6d0b4 main (/opt/compiler-explorer/clang-trunk/bin/clang+++0xc6d0b4)
#<!-- -->31 0x00007143efc29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#<!-- -->32 0x00007143efc29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#<!-- -->33 0x0000000000db8db5 _start (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdb8db5)
Compiler returned: 1

[c-rhodes]

It's using the SPIR_KERNEL calling convention which isn't supported: https://godbolt.org/z/j1WrqrvoE.

On RISCV they just used the default CC (#69282), this compiles doing the same for AArch64:

diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index d3515cf81f44..964e3946cd61 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -7977,6 +7977,7 @@ CCAssignFn *AArch64TargetLowering::CCAssignFnForCall(CallingConv::ID CC,
   case CallingConv::SwiftTail:
   case CallingConv::Tail:
   case CallingConv::GRAAL:
+  case CallingConv::SPIR_KERNEL:
     if (Subtarget->isTargetWindows()) {
       if (IsVarArg) {
         if (Subtarget->isWindowsArm64EC())

although looking at the docs for this CC https://llvm.org/doxygen/namespacellvm_1_1CallingConv.html#ad345f4a3743a05b620710af99dd2bab9a9b5e79699935bf721647d44339701860 there are various constraints that may need handling.

[k-arrows]

__attribute__((amdgpu_kernel)) has the same problem:
https://godbolt.org/z/4G3rfdMd1