When trying to build https://gitorious.org/arm-neon-tests/arm-neon-tests with clang, clang crashes with assertion failures. Below are 2 small reproducers, which each trigger a different assert. These snippets use the "X" inline assembly constraint to avoid the inline assembly being reordered with the computations happening later. The technique is explained in detail at http://www.ethernut.de/en/documents/arm-inline-asm.html, under section "C code optimization". $ cat t2.c double f2(double f, int pscr_value) { asm volatile("vmsr fpscr,%1" : "=X" ((f)): "r" (pscr_value)); return f+f; } $ cat t3.c typedef signed char int8_t; typedef __attribute__((neon_vector_type(8))) int8_t int8x8_t; void f (void) { int8x8_t vector_res_int8x8; unsigned int fpscr; asm volatile ("vmsr fpscr,%1" : "=X" ((vector_res_int8x8)) : "r" (fpscr)); } $ ~/dev/llvm.org/build/bin/clang -target armv7a-none-eabi -c -mcpu=cortex-a9 -mfloat-abi=hard -S -O -o- t2.c .text .syntax unified .eabi_attribute 67, "2.09" @ Tag_conformance .cpu cortex-a9 .eabi_attribute 6, 10 @ Tag_CPU_arch .eabi_attribute 7, 65 @ Tag_CPU_arch_profile .eabi_attribute 8, 1 @ Tag_ARM_ISA_use .eabi_attribute 9, 2 @ Tag_THUMB_ISA_use .fpu neon-fp16 .eabi_attribute 17, 1 @ Tag_ABI_PCS_GOT_use .eabi_attribute 20, 1 @ Tag_ABI_FP_denormal .eabi_attribute 21, 1 @ Tag_ABI_FP_exceptions .eabi_attribute 23, 3 @ Tag_ABI_FP_number_model .eabi_attribute 34, 0 @ Tag_CPU_unaligned_access .eabi_attribute 24, 1 @ Tag_ABI_align_needed .eabi_attribute 25, 1 @ Tag_ABI_align_preserved .eabi_attribute 28, 1 @ Tag_ABI_VFP_args .eabi_attribute 36, 1 @ Tag_FP_HP_extension .eabi_attribute 38, 1 @ Tag_ABI_FP_16bit_format .eabi_attribute 42, 1 @ Tag_MPextension_use .eabi_attribute 18, 4 @ Tag_ABI_PCS_wchar_t .eabi_attribute 26, 2 @ Tag_ABI_enum_size .eabi_attribute 14, 0 @ Tag_ABI_PCS_R9_use .eabi_attribute 68, 1 @ Tag_Virtualization_use .file "t2.c" Assertion failed: (ConstraintID != InlineAsm::Constraint_Unknown && "Failed to convert memory constraint code to constraint id."), function visitInlineAsm, file /Users/kribey01/dev/llvm.org/llvm-clang-compiler-rt /lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp, line 6401. 0 clang-3.9 0x0000000101f6f96b llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 43 1 clang-3.9 0x0000000101f6ebe6 llvm::sys::RunSignalHandlers() + 70 2 clang-3.9 0x0000000101f70012 SignalHandler(int) + 322 3 libsystem_platform.dylib 0x00007fff8e779f1a _sigtramp + 26 4 clang-3.9 0x0000000104041fd7 clang::Stmt::StatisticsEnabled + 92386 5 clang-3.9 0x0000000101f6fe26 abort + 22 6 clang-3.9 0x0000000101f6fe01 __assert_rtn + 81 7 clang-3.9 0x00000001025e4eff llvm::SelectionDAGBuilder::visitInlineAsm(llvm::ImmutableCallSite) + 15695 8 clang-3.9 0x00000001025cd895 llvm::SelectionDAGBuilder::visit(llvm::Instruction const&) + 69 9 clang-3.9 0x000000010264c2e8 llvm::SelectionDAGISel::SelectBasicBlock(llvm::ilist_iterator<llvm::Instruction const>, llvm::ilist_iterator<llvm::Instruction const>, bool&) + 40 10 clang-3.9 0x000000010264bf74 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) + 6612 11 clang-3.9 0x0000000102649554 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) + 2020 12 clang-3.9 0x000000010108f4f4 (anonymous namespace)::ARMDAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) + 20 13 clang-3.9 0x00000001019b94dc llvm::MachineFunctionPass::runOnFunction(llvm::Function&) + 140 14 clang-3.9 0x0000000101b9acd8 llvm::FPPassManager::runOnFunction(llvm::Function&) + 328 15 clang-3.9 0x0000000101b9af2b llvm::FPPassManager::runOnModule(llvm::Module&) + 43 16 clang-3.9 0x0000000101b9b3b6 llvm::legacy::PassManagerImpl::run(llvm::Module&) + 806 17 clang-3.9 0x00000001020cb6be clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Modu le*, clang::BackendAction, llvm::raw_pwrite_stream*) + 8750 18 clang-3.9 0x000000010223c502 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) + 514 19 clang-3.9 0x000000010290cdd5 clang::ParseAST(clang::Sema&, bool, bool) + 581 20 clang-3.9 0x000000010240c69b clang::FrontendAction::Execute() + 75 21 clang-3.9 0x00000001023d2e81 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 1073 22 clang-3.9 0x000000010244b3bf clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 4047 23 clang-3.9 0x0000000100df7da3 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) + 1491 24 clang-3.9 0x0000000100df67d0 main + 11568 25 libdyld.dylib 0x00007fff9aabd5c9 start + 1 Stack dump: 0. Program arguments: /Users/kribey01/dev/llvm.org/build/bin/clang-3.9 -cc1 -triple armv7-none--eabi -S -disable-free -main-file-name t2.c -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fm ath-errno -masm-verbose -mconstructor-aliases -target-cpu cortex-a9 -target-feature +strict-align -target-abi aapcs -mfloat-abi hard -target-linker-version 253.6 -dwarf-column-info -debugger-tuning=gdb -coverage- file /Users/kribey01/dev/triage/android/201602_arm_neon_tests/arm-neon-tests/- -resource-dir /Users/kribey01/dev/llvm.org/build/bin/../lib/clang/3.9.0 -O2 -fdebug-compilation-dir /Users/kribey01/dev/triage/androi d/201602_arm_neon_tests/arm-neon-tests -ferror-limit 19 -fmessage-length 212 -fallow-half-arguments-and-returns -fno-signed-char -fobjc-runtime=gcc -fdiagnostics-show-option -fcolor-diagnostics -vectorize-loops - vectorize-slp -o - -x c t2.c 1. <eof> parser at end of file 2. Code generation 3. Running pass 'Function Pass Manager' on module 't2.c'. 4. Running pass 'ARM Instruction Selection' on function '@f2' clang-3.9: error: unable to execute command: Illegal instruction: 4 clang-3.9: error: clang frontend command failed due to signal (use -v to see invocation) clang version 3.9.0 (ssh://kribey01@e103606-lin.cambridge.arm.com/work/llvm.org/llvm-clang-compiler-rt/tools/clang da6e53c2620d92ec6ff16c23af69c4e531d23417) (ssh://kribey01@e103606-lin.cambridge.arm.com/work/llvm .org/llvm-clang-compiler-rt bb152043ce23844ccd348b0cde05f301b1319b70) Target: armv7a-none--eabi Thread model: posix InstalledDir: /Users/kribey01/dev/llvm.org/build/bin clang-3.9: note: diagnostic msg: PLEASE submit a bug report to http://llvm.org/bugs/ and include the crash backtrace, preprocessed source, and associated run script. clang-3.9: note: diagnostic msg: ******************** PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT: Preprocessed source(s) and associated run script(s) are located at: clang-3.9: note: diagnostic msg: /var/folders/th/cnt0054d153g3xf5rt87856x_1kq80/T/t2-07d0cb.c clang-3.9: note: diagnostic msg: /var/folders/th/cnt0054d153g3xf5rt87856x_1kq80/T/t2-07d0cb.sh clang-3.9: note: diagnostic msg: ******************** $ ~/dev/llvm.org/build/bin/clang -target armv7a-none-eabi -c -mcpu=cortex-a9 -mfloat-abi=hard -S -O -o- t3.c .text .syntax unified .eabi_attribute 67, "2.09" @ Tag_conformance .cpu cortex-a9 .eabi_attribute 6, 10 @ Tag_CPU_arch .eabi_attribute 7, 65 @ Tag_CPU_arch_profile .eabi_attribute 8, 1 @ Tag_ARM_ISA_use .eabi_attribute 9, 2 @ Tag_THUMB_ISA_use .fpu neon-fp16 .eabi_attribute 17, 1 @ Tag_ABI_PCS_GOT_use .eabi_attribute 20, 1 @ Tag_ABI_FP_denormal .eabi_attribute 21, 1 @ Tag_ABI_FP_exceptions .eabi_attribute 23, 3 @ Tag_ABI_FP_number_model .eabi_attribute 34, 0 @ Tag_CPU_unaligned_access .eabi_attribute 24, 1 @ Tag_ABI_align_needed .eabi_attribute 25, 1 @ Tag_ABI_align_preserved .eabi_attribute 28, 1 @ Tag_ABI_VFP_args .eabi_attribute 36, 1 @ Tag_FP_HP_extension .eabi_attribute 38, 1 @ Tag_ABI_FP_16bit_format .eabi_attribute 42, 1 @ Tag_MPextension_use .eabi_attribute 18, 4 @ Tag_ABI_PCS_wchar_t .eabi_attribute 26, 2 @ Tag_ABI_enum_size .eabi_attribute 14, 0 @ Tag_ABI_PCS_R9_use .eabi_attribute 68, 1 @ Tag_Virtualization_use .file "t3.c" Assertion failed: (Val && "isa<> used on a null pointer"), function doit, file /Users/kribey01/dev/llvm.org/llvm-clang-compiler-rt/include/llvm/Support/Casting.h, line 95. 0 clang-3.9 0x000000010721196b llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 43 1 clang-3.9 0x0000000107210be6 llvm::sys::RunSignalHandlers() + 70 2 clang-3.9 0x0000000107212012 SignalHandler(int) + 322 3 libsystem_platform.dylib 0x00007fff8e779f1a _sigtramp + 26 4 clang-3.9 0x00000001092e3fe6 clang::Stmt::StatisticsEnabled + 92401 5 clang-3.9 0x0000000107211e26 abort + 22 6 clang-3.9 0x0000000107211e01 __assert_rtn + 81 7 clang-3.9 0x00000001078a50b7 diagnosePossiblyInvalidConstraint(llvm::LLVMContext&, llvm::Value const*, llvm::Twine const&) + 247 8 clang-3.9 0x000000010786b062 getCopyFromParts(llvm::SelectionDAG&, llvm::SDLoc, llvm::SDValue const*, unsigned int, llvm::MVT, llvm::EVT, llvm::Value const*, llvm::ISD::NodeType) + 2114 9 clang-3.9 0x000000010786a662 llvm::RegsForValue::getCopyFromRegs(llvm::SelectionDAG&, llvm::FunctionLoweringInfo&, llvm::SDLoc, llvm::SDValue&, llvm::SDValue*, llvm::Value const*) const + 2498 10 clang-3.9 0x000000010788605b llvm::SelectionDAGBuilder::visitInlineAsm(llvm::ImmutableCallSite) + 11947 11 clang-3.9 0x000000010786f895 llvm::SelectionDAGBuilder::visit(llvm::Instruction const&) + 69 12 clang-3.9 0x00000001078ee2e8 llvm::SelectionDAGISel::SelectBasicBlock(llvm::ilist_iterator<llvm::Instruction const>, llvm::ilist_iterator<llvm::Instruction const>, bool&) + 40 13 clang-3.9 0x00000001078edf74 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) + 6612 14 clang-3.9 0x00000001078eb554 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) + 2020 15 clang-3.9 0x00000001063314f4 (anonymous namespace)::ARMDAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) + 20 16 clang-3.9 0x0000000106c5b4dc llvm::MachineFunctionPass::runOnFunction(llvm::Function&) + 140 17 clang-3.9 0x0000000106e3ccd8 llvm::FPPassManager::runOnFunction(llvm::Function&) + 328 18 clang-3.9 0x0000000106e3cf2b llvm::FPPassManager::runOnModule(llvm::Module&) + 43 19 clang-3.9 0x0000000106e3d3b6 llvm::legacy::PassManagerImpl::run(llvm::Module&) + 806 20 clang-3.9 0x000000010736d6be clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Mod le*, clang::BackendAction, llvm::raw_pwrite_stream*) + 8750 21 clang-3.9 0x00000001074de502 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) + 514 22 clang-3.9 0x0000000107baedd5 clang::ParseAST(clang::Sema&, bool, bool) + 581 23 clang-3.9 0x00000001076ae69b clang::FrontendAction::Execute() + 75 24 clang-3.9 0x0000000107674e81 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 1073 25 clang-3.9 0x00000001076ed3bf clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 4047 26 clang-3.9 0x0000000106099da3 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) + 1491 27 clang-3.9 0x00000001060987d0 main + 11568 28 libdyld.dylib 0x00007fff9aabd5c9 start + 1 Stack dump: 0. Program arguments: /Users/kribey01/dev/llvm.org/build/bin/clang-3.9 -cc1 -triple armv7-none--eabi -S -disable-free -main-file-name t3.c -mrelocation-model static -mthread-model posix -mdisable-fp-elim -f ath-errno -masm-verbose -mconstructor-aliases -target-cpu cortex-a9 -target-feature +strict-align -target-abi aapcs -mfloat-abi hard -target-linker-version 253.6 -dwarf-column-info -debugger-tuning=gdb -coverage file /Users/kribey01/dev/triage/android/201602_arm_neon_tests/arm-neon-tests/- -resource-dir /Users/kribey01/dev/llvm.org/build/bin/../lib/clang/3.9.0 -O2 -fdebug-compilation-dir /Users/kribey01/dev/triage/andro d/201602_arm_neon_tests/arm-neon-tests -ferror-limit 19 -fmessage-length 212 -fallow-half-arguments-and-returns -fno-signed-char -fobjc-runtime=gcc -fdiagnostics-show-option -fcolor-diagnostics -vectorize-loops vectorize-slp -o - -x c t3.c 1. <eof> parser at end of file 2. Code generation 3. Running pass 'Function Pass Manager' on module 't3.c'. 4. Running pass 'ARM Instruction Selection' on function '@f' clang-3.9: error: unable to execute command: Illegal instruction: 4 clang-3.9: error: clang frontend command failed due to signal (use -v to see invocation) clang version 3.9.0 (ssh://kribey01@e103606-lin.cambridge.arm.com/work/llvm.org/llvm-clang-compiler-rt/tools/clang da6e53c2620d92ec6ff16c23af69c4e531d23417) (ssh://kribey01@e103606-lin.cambridge.arm.com/work/llv .org/llvm-clang-compiler-rt bb152043ce23844ccd348b0cde05f301b1319b70) Target: armv7a-none--eabi Thread model: posix InstalledDir: /Users/kribey01/dev/llvm.org/build/bin clang-3.9: note: diagnostic msg: PLEASE submit a bug report to http://llvm.org/bugs/ and include the crash backtrace, preprocessed source, and associated run script. clang-3.9: note: diagnostic msg: ******************** PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT: Preprocessed source(s) and associated run script(s) are located at: clang-3.9: note: diagnostic msg: /var/folders/th/cnt0054d153g3xf5rt87856x_1kq80/T/t3-c62f0b.c clang-3.9: note: diagnostic msg: /var/folders/th/cnt0054d153g3xf5rt87856x_1kq80/T/t3-c62f0b.sh clang-3.9: note: diagnostic msg: ********************
I'm assuming that similar asserts can be triggered for at least the AArch64 backend, but I haven't tested that yet.
This should now work on ARM.
Silviu, do you know of a specific CL that fixes this, or were there multiple CLs?
Sorry, should be just r267411.
Also fixed the AArch64 side in r268907.