[RISC-V] Clang crashes when building with optimization level 2

[OMaghiarIMG]

Hello, ran into the following error on a RISC-V build when setting optimization level to -O2:

fatal error: error in backend: Invalid size request on a scalable vector.
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: /home/omaghiar/riscv-gnu-toolchain/build/bin/clang++ -o tests/common.o -static -O2 -Wall -Wcast-qual -I. -march=rv64gcv_zba -c -MMD -MF tests/common.o.d tests/common.cpp
1.      <eof> parser at end of file
2.      Optimizer
 #0 0x000055a9ba5d5ebf llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c7bebf)
 #1 0x000055a9ba5d3f0c llvm::sys::CleanupOnSignal(unsigned long) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c79f0c)
 #2 0x000055a9ba5223d7 llvm::CrashRecoveryContext::HandleExit(int) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1bc83d7)
 #3 0x000055a9ba5cb382 llvm::sys::Process::Exit(int, bool) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c71382)
 #4 0x000055a9b9608b56 (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xcaeb56)
 #5 0x000055a9ba52980a llvm::report_fatal_error(llvm::Twine const&, bool) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1bcf80a)
 #6 0x000055a9ba52999e (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1bcf99e)
 #7 0x000055a9ba57761d (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c1d61d)
 #8 0x000055a9ba577644 llvm::TypeSize::operator unsigned long() const (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c1d644)
 #9 0x000055a9b99d03e4 llvm::isSafeToLoadUnconditionally(llvm::Value*, llvm::Align, llvm::APInt&, llvm::DataLayout const&, llvm::Instruction*, llvm::AssumptionCache*, llvm::DominatorTree const*, llvm::TargetLibraryInfo const*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x10763e4)
#10 0x000055a9b99d1d0d llvm::isSafeToLoadUnconditionally(llvm::Value*, llvm::Type*, llvm::Align, llvm::DataLayout const&, llvm::Instruction*, llvm::AssumptionCache*, llvm::DominatorTree const*, llvm::TargetLibraryInfo const*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1077d0d)
#11 0x000055a9bbdcf380 (anonymous namespace)::VectorCombine::widenSubvectorLoad(llvm::Instruction&) VectorCombine.cpp:0:0
#12 0x000055a9bbddaa37 llvm::VectorCombinePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x3480a37)
#13 0x000055a9bb847d26 llvm::detail::PassModel<llvm::Function, llvm::VectorCombinePass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x2eedd26)
#14 0x000055a9ba821ca4 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1ec7ca4)
#15 0x000055a9ba0f9e5e llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x179fe5e)
#16 0x000055a9ba81c0c6 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1ec20c6)
#17 0x000055a9ba0f6900 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x179c900)
#18 0x000055a9ba82dfe8 (anonymous namespace)::EmitAssemblyHelper::RunOptimizationPipeline(clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>&, std::unique_ptr<llvm::ToolOutputFile, std::default_delete<llvm::ToolOutputFile>>&, clang::BackendConsumer*) BackendUtil.cpp:0:0
#19 0x000055a9ba83131b 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::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1ed731b)
#20 0x000055a9bae0cc2e clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24b2c2e)
#21 0x000055a9bca36099 clang::ParseAST(clang::Sema&, bool, bool) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x40dc099)
#22 0x000055a9bae0c005 clang::CodeGenAction::ExecuteAction() (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24b2005)
#23 0x000055a9bb09f3b1 clang::FrontendAction::Execute() (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x27453b1)
#24 0x000055a9bb01a2db clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x26c02db)
#25 0x000055a9bb17f50b clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x282550b)
#26 0x000055a9b960a81d cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xcb081d)
#27 0x000055a9b960331d ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#28 0x000055a9bae5506d 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
#29 0x000055a9ba5222c7 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1bc82c7)
#30 0x000055a9bae5550c 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
#31 0x000055a9bae1bc5e clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24c1c5e)
#32 0x000055a9bae1c62d clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24c262d)
#33 0x000055a9bae26bdc clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24ccbdc)
#34 0x000055a9b9607c11 clang_main(int, char**, llvm::ToolContext const&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xcadc11)
#35 0x000055a9b9555f1b main (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xbfbf1b)
#36 0x00007f9ab2956083 __libc_start_main /build/glibc-wuryBv/glibc-2.31/csu/../csu/libc-start.c:342:3
#37 0x000055a9b9602ade _start (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xca8ade)
clang++: error: clang frontend command failed with exit code 70 (use -v to see invocation)
clang version 18.1.0rc (https://github.com/llvm/llvm-project.git 6c90f8dd546334b01c9a86387950e8c72d459f1e)
Target: riscv64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/omaghiar/riscv-gnu-toolchain/build/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: /tmp/common-9cdfcc.cpp
clang++: note: diagnostic msg: /tmp/common-9cdfcc.sh
clang++: note: diagnostic msg: 

********************
make: *** [Makefile:61: tests/common.o] Error 1

Tested on main(bc1c86b) and release/18.x(6c90f8d) branches.
Attached preprocessed file:
common.txt
clang++ -x c++-cpp-output -O2 -march=rv64gcv -c common.txt

Full context:

Building the neon2rvv project(https://github.com/howjmay/neon2rvv) with riscv-gnu-toolchain. Clang version newer than 17 required for latest RVV intrinsics API changes. Clang works when building with -O0/O1 but fails with -O2.

git clone https://github.com/howjmay/neon2rvv.git
cd neon2rvv
# set -O2 in Makefile#L20
export CROSS_COMPILE=/path/to/toolchain/riscv64-unknown-linux-gnu-
make CC=clang CXX=clang++

[OMaghiarIMG]

Attached preprocessed source and associated run script:
common-3ccbc6.zip

[llvmbot]

@llvm/issue-subscribers-backend-risc-v

Author: None (OMaghiarIMG)

Hello, ran into the following error on a RISC-V build when setting optimization level to -O2: ``` fatal error: error in backend: Invalid size request on a scalable vector. 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: /home/omaghiar/riscv-gnu-toolchain/build/bin/clang++ -o tests/common.o -static -O2 -Wall -Wcast-qual -I. -march=rv64gcv_zba -c -MMD -MF tests/common.o.d tests/common.cpp 1. <eof> parser at end of file 2. Optimizer #0 0x000055a9ba5d5ebf llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c7bebf) #1 0x000055a9ba5d3f0c llvm::sys::CleanupOnSignal(unsigned long) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c79f0c) #2 0x000055a9ba5223d7 llvm::CrashRecoveryContext::HandleExit(int) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1bc83d7) #3 0x000055a9ba5cb382 llvm::sys::Process::Exit(int, bool) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c71382) #4 0x000055a9b9608b56 (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xcaeb56) #5 0x000055a9ba52980a llvm::report_fatal_error(llvm::Twine const&, bool) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1bcf80a) #6 0x000055a9ba52999e (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1bcf99e) #7 0x000055a9ba57761d (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c1d61d) #8 0x000055a9ba577644 llvm::TypeSize::operator unsigned long() const (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1c1d644) #9 0x000055a9b99d03e4 llvm::isSafeToLoadUnconditionally(llvm::Value*, llvm::Align, llvm::APInt&, llvm::DataLayout const&, llvm::Instruction*, llvm::AssumptionCache*, llvm::DominatorTree const*, llvm::TargetLibraryInfo const*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x10763e4) #10 0x000055a9b99d1d0d llvm::isSafeToLoadUnconditionally(llvm::Value*, llvm::Type*, llvm::Align, llvm::DataLayout const&, llvm::Instruction*, llvm::AssumptionCache*, llvm::DominatorTree const*, llvm::TargetLibraryInfo const*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1077d0d) #11 0x000055a9bbdcf380 (anonymous namespace)::VectorCombine::widenSubvectorLoad(llvm::Instruction&) VectorCombine.cpp:0:0 #12 0x000055a9bbddaa37 llvm::VectorCombinePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x3480a37) #13 0x000055a9bb847d26 llvm::detail::PassModel<llvm::Function, llvm::VectorCombinePass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x2eedd26) #14 0x000055a9ba821ca4 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1ec7ca4) #15 0x000055a9ba0f9e5e llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x179fe5e) #16 0x000055a9ba81c0c6 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1ec20c6) #17 0x000055a9ba0f6900 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x179c900) #18 0x000055a9ba82dfe8 (anonymous namespace)::EmitAssemblyHelper::RunOptimizationPipeline(clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>&, std::unique_ptr<llvm::ToolOutputFile, std::default_delete<llvm::ToolOutputFile>>&, clang::BackendConsumer*) BackendUtil.cpp:0:0 #19 0x000055a9ba83131b 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::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1ed731b) #20 0x000055a9bae0cc2e clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24b2c2e) #21 0x000055a9bca36099 clang::ParseAST(clang::Sema&, bool, bool) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x40dc099) #22 0x000055a9bae0c005 clang::CodeGenAction::ExecuteAction() (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24b2005) #23 0x000055a9bb09f3b1 clang::FrontendAction::Execute() (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x27453b1) #24 0x000055a9bb01a2db clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x26c02db) #25 0x000055a9bb17f50b clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x282550b) #26 0x000055a9b960a81d cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xcb081d) #27 0x000055a9b960331d ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0 #28 0x000055a9bae5506d 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 #29 0x000055a9ba5222c7 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x1bc82c7) #30 0x000055a9bae5550c 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 #31 0x000055a9bae1bc5e clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24c1c5e) #32 0x000055a9bae1c62d clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24c262d) #33 0x000055a9bae26bdc clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0x24ccbdc) #34 0x000055a9b9607c11 clang_main(int, char**, llvm::ToolContext const&) (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xcadc11) #35 0x000055a9b9555f1b main (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xbfbf1b) #36 0x00007f9ab2956083 __libc_start_main /build/glibc-wuryBv/glibc-2.31/csu/../csu/libc-start.c:342:3 #37 0x000055a9b9602ade _start (/home/omaghiar/riscv-gnu-toolchain/build/bin/clang+++0xca8ade) clang++: error: clang frontend command failed with exit code 70 (use -v to see invocation) clang version 18.1.0rc (https://github.com/llvm/llvm-project.git 6c90f8d) Target: riscv64-unknown-linux-gnu Thread model: posix InstalledDir: /home/omaghiar/riscv-gnu-toolchain/build/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: /tmp/common-9cdfcc.cpp
clang++: note: diagnostic msg: /tmp/common-9cdfcc.sh
clang++: note: diagnostic msg:

---

make: *** [Makefile:61: tests/common.o] Error 1

Tested on main(bc1c86b810e518a8e3fa90d5c26908c43788873d) and release/18.x(6c90f8dd546334b01c9a86387950e8c72d459f1e) branches.
Attached preprocessed file:
[common.txt](https://github.com/llvm/llvm-project/files/14372209/common.txt)
`clang++ -x c++-cpp-output -O2 -march=rv64gcv -c common.txt`

### Full context:
Building the neon2rvv project(https://github.com/howjmay/neon2rvv) with riscv-gnu-toolchain. Clang version newer than 17 required for latest RVV intrinsics API changes. Clang works when building with -O0/O1 but fails with -O2.

git clone https://github.com/howjmay/neon2rvv.git
cd neon2rvv

set -O2 in Makefile#L20

export CROSS_COMPILE=/path/to/toolchain/riscv64-unknown-linux-gnu-
make CC=clang CXX=clang++

</details>

[lukel97]

/cherry-pick b0edc1c

[llvmbot]

/pull-request #82664