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[SYCL] POCL SPIR Builtin Translation #10

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agozillon opened this issue Apr 15, 2019 · 2 comments
Open

[SYCL] POCL SPIR Builtin Translation #10

agozillon opened this issue Apr 15, 2019 · 2 comments
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enhancement New feature or request

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@agozillon
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agozillon commented Apr 15, 2019

As an extension to #9 there are currently some incorrectly mangled SPIR builtins in POCL (pocl/pocl#698) that will need to be handled for clean execution of SYCL spir-df output by a POCL runtime.

The incorrect mangling appears to be caused by some type aliasing via using declarations in POCL's _builtin_renames.h file and currently affects a significant amount of math functions, some atomics and printf.

I can currently see this being handled in one of two ways:

  • Rework the existing POCL implementation to use the correct function names and then put in a pull request to try and change the upstream implementation. This would be the ideal long-term avenue, but may be very difficult as there will most likely be some reason behind the renaming of these builtins that could be a far reaching problem.
  • Alter the InSPIRation pass to optionally translate the correct SPIR mangled names to the altered POCL renamed builtins, effectively by passing the need to alter POCL. The easier of the two options but inflicts a certain amount of code debt on us and if the POCL issue gets fixed then we'll have to alter the InSPIRation pass again.
@agozillon agozillon added the enhancement New feature or request label Apr 15, 2019
@franz
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franz commented Sep 6, 2019

Hello,

This was partially resolved in git master. There is now a script, which generates a "wrapper" with correctly mangled SPIR names, calling the pocl's kernel library functions. Partially resolved because it does not contain every possible SPIR opencl name (vectorized ones are missing, plus a few others), and it's only for the CPU device.

some reason behind the renaming of these builtins that could be a far reaching problem

The original reason (at least IIRC) was that many kernel library functions were calling libc's math functions, so to avoid name clashes, pocl renamed kernel functions with macros. This is no longer an issue as pocl doesn't use libm anymore. But unfortunately removing the rename macros doesn't solve the problem. There are two reasons:

  1. Argument address spaces. SPIR has fixed address space numbers, but pocl's kernel library uses target address spaces, which are different for every device. E.g. in the library for CPU device, all OpenCL AS map to a single target AS: zero; while library for CUDA uses SPIR numbers (IIRC). This has to be handled somewhere by address casts.

  2. The calling convention. SPIR has its own LLVM calling convention (spir_func), while pocl's kernel library use their target's. Certain passes in LLVM have a feature, where if a function is called with the wrong convention, it's replaced by "llvm_unreachable".

So for these reasons, i've created a python script which generates said wrapper. Please give it a try (via pocl git master) when you have time.

@agozillon
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Thank you very much for looking into this and updating us, I'll take a look into this to make sure when I get a chance! And thanks for the detailed breakdown of the problem.

Ralender pushed a commit to Ralender/sycl that referenced this issue Jul 1, 2020
  CONFLICT (content): Merge conflict in clang/test/Preprocessor/sycl-macro.cpp
  CONFLICT (content): Merge conflict in clang/test/Driver/sycl.c
  CONFLICT (content): Merge conflict in clang/lib/Frontend/CompilerInvocation.cpp
  CONFLICT (content): Merge conflict in clang/lib/Driver/ToolChains/Clang.cpp
  CONFLICT (content): Merge conflict in clang/include/clang/Basic/LangOptions.def
Ralender pushed a commit to Ralender/sycl that referenced this issue Jul 1, 2020
keryell pushed a commit that referenced this issue Nov 10, 2020
  CONFLICT (content): Merge conflict in clang/include/clang/Basic/DiagnosticDriverKinds.td
keryell added a commit that referenced this issue Jul 26, 2021
AIE merge of the opensource changes into the internal branch.
keryell pushed a commit that referenced this issue Dec 7, 2021
  CONFLICT (content): Merge conflict in clang/utils/TableGen/ClangAttrEmitter.cpp
keryell pushed a commit that referenced this issue Oct 6, 2022
…ned form

The DWARF spec says:

 Any debugging information entry representing the declaration of an object,
 module, subprogram or type may have DW_AT_decl_file, DW_AT_decl_line and
 DW_AT_decl_column attributes, each of whose value is an unsigned integer
							 ^^^^^^^^
 constant.

If however, a producer happens to emit DW_AT_decl_file /
DW_AT_decl_line using a signed integer form, llvm-dwarfdump crashes,
like so:

     (... snip ...)
     0x000000b4:   DW_TAG_structure_type
                     DW_AT_name      ("test_struct")
                     DW_AT_byte_size (136)
                     DW_AT_decl_file (llvm-dwarfdump: (... snip ...)/llvm/include/llvm/ADT/Optional.h:197: T& llvm::optional_detail::OptionalStorage<T, true>::getValue() &
 [with T = long unsigned int]: Assertion `hasVal' failed.
     PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
     Stack dump:
     0.      Program arguments: /opt/rocm/llvm/bin/llvm-dwarfdump ./testsuite/outputs/gdb.rocm/lane-pc-vega20/lane-pc-vega20-kernel.so
      #0 0x000055cc8e78315f PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
      #1 0x000055cc8e780d3d SignalHandler(int) Signals.cpp:0:0
      #2 0x00007f8f2cae8420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
      #3 0x00007f8f2c58d00b raise /build/glibc-SzIz7B/glibc-2.31/signal/../sysdeps/unix/sysv/linux/raise.c:51:1
      #4 0x00007f8f2c56c859 abort /build/glibc-SzIz7B/glibc-2.31/stdlib/abort.c:81:7
      #5 0x00007f8f2c56c729 get_sysdep_segment_value /build/glibc-SzIz7B/glibc-2.31/intl/loadmsgcat.c:509:8
      #6 0x00007f8f2c56c729 _nl_load_domain /build/glibc-SzIz7B/glibc-2.31/intl/loadmsgcat.c:970:34
      #7 0x00007f8f2c57dfd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
      #8 0x000055cc8e58ceb9 llvm::DWARFDie::dump(llvm::raw_ostream&, unsigned int, llvm::DIDumpOptions) const (/opt/rocm/llvm/bin/llvm-dwarfdump+0x2e0eb9)
      #9 0x000055cc8e58bec3 llvm::DWARFDie::dump(llvm::raw_ostream&, unsigned int, llvm::DIDumpOptions) const (/opt/rocm/llvm/bin/llvm-dwarfdump+0x2dfec3)
     #10 0x000055cc8e5b28a3 llvm::DWARFCompileUnit::dump(llvm::raw_ostream&, llvm::DIDumpOptions) (.part.21) DWARFCompileUnit.cpp:0:0

Likewise with DW_AT_call_file / DW_AT_call_line.

The problem is that the code in llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
dumping these attributes assumes that
FormValue.getAsUnsignedConstant() returns an armed optional.  If in
debug mode, we get an assertion line the above.  If in release mode,
and asserts are compiled out, then we proceed as if the optional had a
value, running into undefined behavior, printing whatever random
value.

Fix this by checking whether the optional returned by
FormValue.getAsUnsignedConstant() has a value, like done in other
places.

In addition, DWARFVerifier.cpp is validating DW_AT_call_file /
DW_AT_decl_file, but not AT_call_line / DW_AT_decl_line.  This commit
fixes that too.

The llvm-dwarfdump/X86/verify_file_encoding.yaml testcase is extended
to cover these cases.  Current llvm-dwarfdump crashes running the
newly-extended test.

"make check-llvm-tools-llvm-dwarfdump" shows no regressions, on x86-64
GNU/Linux.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D129392
keryell pushed a commit that referenced this issue Jan 4, 2023
Found by msan -fsanitize-memory-use-after-dtor.

==8259==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x55dbec54d2b8 in dtorRecord(clang::interp::Block*, char*, clang::interp::Descriptor*) clang/lib/AST/Interp/Descriptor.cpp:150:22
    #1 0x55dbec54bfcf in dtorArrayDesc(clang::interp::Block*, char*, clang::interp::Descriptor*) clang/lib/AST/Interp/Descriptor.cpp:97:7
    #2 0x55dbec508578 in invokeDtor clang/lib/AST/Interp/InterpBlock.h:79:7
    #3 0x55dbec508578 in clang::interp::Program::~Program() clang/lib/AST/Interp/Program.h:55:19
    #4 0x55dbec50657a in operator() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:55:5
    #5 0x55dbec50657a in std::__msan::unique_ptr<clang::interp::Program, std::__msan::default_delete<clang::interp::Program>>::~unique_ptr() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:261:7
    #6 0x55dbec5035a1 in clang::interp::Context::~Context() clang/lib/AST/Interp/Context.cpp:27:22
    #7 0x55dbebec1daa in operator() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:55:5
    #8 0x55dbebec1daa in std::__msan::unique_ptr<clang::interp::Context, std::__msan::default_delete<clang::interp::Context>>::~unique_ptr() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:261:7
    #9 0x55dbebe285f9 in clang::ASTContext::~ASTContext() clang/lib/AST/ASTContext.cpp:1038:40
    #10 0x55dbe941ff13 in llvm::RefCountedBase<clang::ASTContext>::Release() const llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:101:7
    #11 0x55dbe94353ef in release llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:159:38
    #12 0x55dbe94353ef in release llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:224:7
    #13 0x55dbe94353ef in ~IntrusiveRefCntPtr llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:191:27
    #14 0x55dbe94353ef in clang::CompilerInstance::setASTContext(clang::ASTContext*) clang/lib/Frontend/CompilerInstance.cpp:178:3
    #15 0x55dbe95ad0ad in clang::FrontendAction::EndSourceFile() clang/lib/Frontend/FrontendAction.cpp:1100:8
    #16 0x55dbe9445fcf in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) clang/lib/Frontend/CompilerInstance.cpp:1047:11
    #17 0x55dbe6b3afef in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:266:25
    #18 0x55dbe6b13288 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) clang/tools/driver/cc1_main.cpp:250:15
    #19 0x55dbe6b0095f in ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) clang/tools/driver/driver.cpp:319:12
    #20 0x55dbe6aff41c in clang_main(int, char**) clang/tools/driver/driver.cpp:395:12
    #21 0x7f9be07fa632 in __libc_start_main
    #22 0x55dbe6a702e9 in _start

  Member fields were destroyed
    #0 0x55dbe6a7da5d in __sanitizer_dtor_callback_fields compiler-rt/lib/msan/msan_interceptors.cpp:949:5
    #1 0x55dbec5094ac in ~SmallVectorImpl llvm/include/llvm/ADT/SmallVector.h:479:7
    #2 0x55dbec5094ac in ~SmallVectorImpl llvm/include/llvm/ADT/SmallVector.h:612:3
    #3 0x55dbec5094ac in llvm::SmallVector<clang::interp::Record::Base, 8u>::~SmallVector() llvm/include/llvm/ADT/SmallVector.h:1207:3
    #4 0x55dbec508e79 in clang::interp::Record::~Record() clang/lib/AST/Interp/Record.h:24:7
    #5 0x55dbec508612 in clang::interp::Program::~Program() clang/lib/AST/Interp/Program.h:49:26
    #6 0x55dbec50657a in operator() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:55:5
    #7 0x55dbec50657a in std::__msan::unique_ptr<clang::interp::Program, std::__msan::default_delete<clang::interp::Program>>::~unique_ptr() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:261:7
    #8 0x55dbec5035a1 in clang::interp::Context::~Context() clang/lib/AST/Interp/Context.cpp:27:22
    #9 0x55dbebec1daa in operator() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:55:5
    #10 0x55dbebec1daa in std::__msan::unique_ptr<clang::interp::Context, std::__msan::default_delete<clang::interp::Context>>::~unique_ptr() third_party/crosstool/v18/stable/toolchain/bin/../include/c++/v1/__memory/unique_ptr.h:261:7
    #11 0x55dbebe285f9 in clang::ASTContext::~ASTContext() clang/lib/AST/ASTContext.cpp:1038:40
    #12 0x55dbe941ff13 in llvm::RefCountedBase<clang::ASTContext>::Release() const llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:101:7
    #13 0x55dbe94353ef in release llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:159:38
    #14 0x55dbe94353ef in release llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:224:7
    #15 0x55dbe94353ef in ~IntrusiveRefCntPtr llvm/include/llvm/ADT/IntrusiveRefCntPtr.h:191:27
    #16 0x55dbe94353ef in clang::CompilerInstance::setASTContext(clang::ASTContext*) clang/lib/Frontend/CompilerInstance.cpp:178:3
    #17 0x55dbe95ad0ad in clang::FrontendAction::EndSourceFile() clang/lib/Frontend/FrontendAction.cpp:1100:8
    #18 0x55dbe9445fcf in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) clang/lib/Frontend/CompilerInstance.cpp:1047:11
    #19 0x55dbe6b3afef in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:266:25
    #20 0x55dbe6b13288 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) clang/tools/driver/cc1_main.cpp:250:15
    #21 0x55dbe6b0095f in ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) clang/tools/driver/driver.cpp:319:12
    #22 0x55dbe6aff41c in clang_main(int, char**) clang/tools/driver/driver.cpp:395:12
    #23 0x7f9be07fa632 in __libc_start_main
    #24 0x55dbe6a702e9 in _start
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