[PATCH] D99142: [RISCV] Add basic cost modelling for fixed vector gather/scatter.

Thu Mar 25 14:09:19 PDT 2021

nathanchance added a comment.

This breaks compiling the Linux kernel for RISC-V (defconfig):

  $ make -skj"$(nproc)" ARCH=riscv CC=clang CROSS_COMPILE=riscv64-linux-gnu- O=build/riscv distclean defconfig drivers/scsi/scsi_common.o
  clang-13: /home/nathan/cbl/github/tc-build/llvm-project/llvm/lib/Target/RISCV/RISCVSubtarget.cpp:124: unsigned int llvm::RISCVSubtarget::getMinRVVVectorSizeInBits() const: Assertion `hasStdExtV() && "Tried to get vector length without V extension support!"' failed.
  PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace, preprocessed source, and associated run script.
  Stack dump:
  0.      Program arguments: /home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13 -cc1 -triple riscv64-unknown-linux-gnu -S -disable-free -main-file-name scsi_common.c -mrelocation-model static -fno-delete-null-pointer-checks -mllvm -warn-stack-size=2048 -mframe-pointer=all -relaxed-aliasing -mdisable-tail-calls -fmath-errno -fno-rounding-math -no-integrated-as -mconstructor-aliases -mcmodel=medium -target-feature +m -target-feature +a -target-feature +c -target-feature +relax -target-feature -save-restore -target-abi lp64 -msmall-data-limit 8 -debugger-tuning=gdb -fcoverage-compilation-dir=/home/nathan/cbl/src/linux/build/riscv -nostdsysteminc -nobuiltininc -resource-dir /home/nathan/cbl/github/tc-build/build/llvm/stage1/lib/clang/13.0.0 -dependency-file drivers/scsi/.scsi_common.o.d -MT drivers/scsi/scsi_common.o -isystem /home/nathan/cbl/github/tc-build/build/llvm/stage1/lib/clang/13.0.0/include -include /home/nathan/cbl/src/linux/include/linux/compiler-version.h -include /home/nathan/cbl/src/linux/include/linux/kconfig.h -include /home/nathan/cbl/src/linux/include/linux/compiler_types.h -I /home/nathan/cbl/src/linux/arch/riscv/include -I ./arch/riscv/include/generated -I /home/nathan/cbl/src/linux/include -I ./include -I /home/nathan/cbl/src/linux/arch/riscv/include/uapi -I ./arch/riscv/include/generated/uapi -I /home/nathan/cbl/src/linux/include/uapi -I ./include/generated/uapi -D __KERNEL__ -D CONFIG_PAGE_OFFSET=0xffffffe000000000 -I /home/nathan/cbl/src/linux/drivers/scsi -I ./drivers/scsi -D KBUILD_MODFILE=\"drivers/scsi/scsi_common\" -D KBUILD_BASENAME=\"scsi_common\" -D KBUILD_MODNAME=\"scsi_common\" -D __KBUILD_MODNAME=kmod_scsi_common -fmacro-prefix-map=/home/nathan/cbl/src/linux/= -O2 -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs -Werror=implicit-function-declaration -Werror=implicit-int -Werror=return-type -Wno-format-security -Werror=unknown-warning-option -Wno-frame-address -Wno-address-of-packed-member -Wno-format-invalid-specifier -Wno-gnu -Wno-unused-const-variable -Wdeclaration-after-statement -Wvla -Wno-pointer-sign -Wno-array-bounds -Werror=date-time -Werror=incompatible-pointer-types -Wno-initializer-overrides -Wno-format -Wno-sign-compare -Wno-format-zero-length -Wno-pointer-to-enum-cast -Wno-tautological-constant-out-of-range-compare -std=gnu89 -fno-dwarf-directory-asm -fdebug-compilation-dir=/home/nathan/cbl/src/linux/build/riscv -ferror-limit 19 -fwrapv -stack-protector 2 -fno-signed-char -fwchar-type=short -fno-signed-wchar -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -o /tmp/scsi_common-bb0ee4.s -x c /home/nathan/cbl/src/linux/drivers/scsi/scsi_common.c
  1.      <eof> parser at end of file
  2.      Optimizer
   #0 0x0000000002b413c3 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x2b413c3)
   #1 0x0000000002b3f22e llvm::sys::RunSignalHandlers() (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x2b3f22e)
   #2 0x0000000002b4188a SignalHandler(int) Signals.cpp:0:0
   #3 0x00007f6951ca5960 __restore_rt sigaction.c:0:0
   #4 0x00007f6951797ef5 raise (/usr/lib/libc.so.6+0x3cef5)
   #5 0x00007f6951781862 abort (/usr/lib/libc.so.6+0x26862)
   #6 0x00007f6951781747 _nl_load_domain.cold loadmsgcat.c:0:0
   #7 0x00007f6951790646 (/usr/lib/libc.so.6+0x35646)
   #8 0x000000000196142d llvm::RISCVSubtarget::getMinRVVVectorSizeInBits() const RISCVSubtarget.cpp:0:0
   #9 0x00000000019be430 llvm::RISCVTTIImpl::getGatherScatterOpCost(unsigned int, llvm::Type*, llvm::Value const*, bool, llvm::Align, llvm::TargetTransformInfo::TargetCostKind, llvm::Instruction const*) RISCVTargetTransformInfo.cpp:0:0
  #10 0x0000000001ec6188 llvm::TargetTransformInfo::getGatherScatterOpCost(unsigned int, llvm::Type*, llvm::Value const*, bool, llvm::Align, llvm::TargetTransformInfo::TargetCostKind, llvm::Instruction const*) const (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x1ec6188)
  #11 0x0000000002cfc60e llvm::slpvectorizer::BoUpSLP::getEntryCost(llvm::slpvectorizer::BoUpSLP::TreeEntry*) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x2cfc60e)
  #12 0x0000000002cffe8e llvm::slpvectorizer::BoUpSLP::getTreeCost() (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x2cffe8e)
  #13 0x0000000002d166a5 tryToVectorizeHorReductionOrInstOperands(llvm::PHINode*, llvm::Instruction*, llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&, llvm::TargetTransformInfo*, llvm::function_ref<bool (llvm::Instruction*, llvm::slpvectorizer::BoUpSLP&)>) SLPVectorizer.cpp:0:0
  #14 0x0000000002d0f072 llvm::SLPVectorizerPass::vectorizeChainsInBlock(llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x2d0f072)
  #15 0x0000000002d0d90c llvm::SLPVectorizerPass::runImpl(llvm::Function&, llvm::ScalarEvolution*, llvm::TargetTransformInfo*, llvm::TargetLibraryInfo*, llvm::AAResults*, llvm::LoopInfo*, llvm::DominatorTree*, llvm::AssumptionCache*, llvm::DemandedBits*, llvm::OptimizationRemarkEmitter*) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x2d0d90c)
  #16 0x0000000002d0ce37 llvm::SLPVectorizerPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x2d0ce37)
  #17 0x0000000003c2655d llvm::detail::PassModel<llvm::Function, llvm::SLPVectorizerPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) PassBuilder.cpp:0:0
  #18 0x00000000024b8835 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x24b8835)
  #19 0x00000000031a626d 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>&) BackendUtil.cpp:0:0
  #20 0x00000000024bc124 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x24bc124)
  #21 0x00000000031a7f2d llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) BackendUtil.cpp:0:0
  #22 0x00000000024b71b8 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x24b71b8)
  #23 0x000000000319c56b (anonymous namespace)::EmitAssemblyHelper::EmitAssemblyWithNewPassManager(clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream> >) BackendUtil.cpp:0:0
  #24 0x0000000003196796 clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::DataLayout const&, llvm::Module*, clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream> >) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x3196796)
  #25 0x00000000036611a9 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) CodeGenAction.cpp:0:0
  #26 0x0000000003d8a4a4 clang::ParseAST(clang::Sema&, bool, bool) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x3d8a4a4)
  #27 0x00000000035b9150 clang::FrontendAction::Execute() (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x35b9150)
  #28 0x00000000034f4c6a clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x34f4c6a)
  #29 0x000000000365b0c8 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x365b0c8)
  #30 0x0000000001940ec4 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x1940ec4)
  #31 0x000000000193e982 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
  #32 0x000000000193e695 main (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x193e695)
  #33 0x00007f6951782b25 __libc_start_main (/usr/lib/libc.so.6+0x27b25)
  #34 0x000000000193b60e _start (/home/nathan/cbl/github/tc-build/build/llvm/stage1/bin/clang-13+0x193b60e)
  clang-13: error: unable to execute command: Aborted (core dumped)
  clang-13: error: clang frontend command failed due to signal (use -v to see invocation)
  ClangBuiltLinux clang version 13.0.0 (https://github.com/llvm/llvm-project 512bae81cc525de436f0d49d11b563f2afd51037)
  Target: riscv64-unknown-linux-gnu
  Thread model: posix
  InstalledDir: /home/nathan/cbl/github/tc-build/build/llvm/stage1/bin
  ...

A reduced reproducer:

  $ cat scsi_common.i
  struct {
    char scsi_lun[8]
  } scsilun_to_int_scsilun;
  scsilun_to_int_i;
  scsilun_to_int() {
    long lun = scsilun_to_int_i = 0;
    for (; scsilun_to_int_i < sizeof(lun); scsilun_to_int_i += 2)
      lun = lun | scsilun_to_int_scsilun.scsi_lun[scsilun_to_int_i] + 1;
    return lun;
  }

  $ clang -O2 --target=riscv64-linux-gnu -c -o /dev/null scsi_common.i
  ...
  clang: /home/nathan/cbl/github/tc-build/llvm-project/llvm/lib/Target/RISCV/RISCVSubtarget.cpp:124: unsigned int llvm::RISCVSubtarget::getMinRVVVectorSizeInBits() const: Assertion `hasStdExtV() && "Tried to get vector length without V extension support!"' failed.
  ...

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D99142/new/

https://reviews.llvm.org/D99142