[llvm] [profcheck] Add unknown branch weights to expanded cmpxchg loop. (PR #165841)

Wed Nov 5 10:54:29 PST 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ml-opt-dev-x86-64` running on `ml-opt-dev-x86-64-b2` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/137/builds/28490

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (build-unified-tree) failure: build (failure)
...
23.477 [1952/64/1943] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/MachOLinkGraphBuilder.cpp.o
23.478 [1951/64/1944] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/ELF.cpp.o
23.480 [1950/64/1945] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/ELFLinkGraphBuilder.cpp.o
23.492 [1949/64/1946] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/ELF_aarch32.cpp.o
23.494 [1948/64/1947] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/ELF_aarch64.cpp.o
23.512 [1947/64/1948] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/ELF_loongarch.cpp.o
23.514 [1946/64/1949] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/ELF_ppc64.cpp.o
23.535 [1945/64/1950] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/ELF_riscv.cpp.o
23.537 [1944/64/1951] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/ELF_x86.cpp.o
23.545 [1943/64/1952] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/AtomicExpandPass.cpp.o
FAILED: lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/AtomicExpandPass.cpp.o 
ccache /usr/bin/c++ -DCPUINFO_SUPPORTED_PLATFORM=1 -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/ml-opt-dev-x86-64-b1/build/lib/CodeGen -I/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/CodeGen -I/b/ml-opt-dev-x86-64-b1/build/include -I/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/include -isystem /tmp/tflitebuild/tensorflow/include -isystem /tmp/tflitebuild/eigen/include/eigen3 -isystem /tmp/tflitebuild/abseil-cpp/include -isystem /tmp/tflitebuild/flatbuffers/include -isystem /tmp/tflitebuild/gemmlowp/include/gemmlowp -isystem /tmp/tflitebuild/ml_dtypes/src/ml_dtypes -isystem /tmp/tflitebuild/ml_dtypes/src/ml_dtypes/ml_dtypes -isystem /tmp/tflitebuild/ruy/include -isystem /tmp/tflitebuild/cpuinfo/include -isystem /tmp/tflitebuild/ARM_NEON_2_x86_SSE/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wno-pass-failed -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -DEIGEN_NEON_GEBP_NR=4 -DTFL_STATIC_LIBRARY_BUILD -std=c++17 -MD -MT lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/AtomicExpandPass.cpp.o -MF lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/AtomicExpandPass.cpp.o.d -o lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/AtomicExpandPass.cpp.o -c /b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/CodeGen/AtomicExpandPass.cpp
/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/CodeGen/AtomicExpandPass.cpp:1694:3: error: no matching function for call to 'setExplicitlyUnknownBranchWeightsIfProfiled'
 1694 |   setExplicitlyUnknownBranchWeightsIfProfiled(*CondBr, *F, DEBUG_TYPE);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/include/llvm/IR/ProfDataUtils.h:200:1: note: candidate function not viable: no known conversion from 'Function' to 'StringRef' for 2nd argument
  200 | setExplicitlyUnknownBranchWeightsIfProfiled(Instruction &I, StringRef PassName,
      | ^                                                           ~~~~~~~~~~~~~~~~~~
1 error generated.
23.545 [1943/63/1953] Building CXX object lib/DebugInfo/Symbolize/CMakeFiles/LLVMSymbolize.dir/SymbolizableObjectFile.cpp.o
In file included from /b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp:13:
In file included from /b/ml-opt-dev-x86-64-b1/llvm-project/llvm/include/llvm/DebugInfo/Symbolize/SymbolizableObjectFile.h:15:
In file included from /b/ml-opt-dev-x86-64-b1/llvm-project/llvm/include/llvm/ADT/StringRef.h:16:
In file included from /usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/algorithm:61:
In file included from /usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_algo.h:61:
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_tempbuf.h:263:8: warning: 'get_temporary_buffer<llvm::symbolize::SymbolizableObjectFile::SymbolDesc>' is deprecated [-Wdeprecated-declarations]
  263 |                 std::get_temporary_buffer<value_type>(_M_original_len));
      |                      ^
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_algo.h:4996:15: note: in instantiation of member function 'std::_Temporary_buffer<__gnu_cxx::__normal_iterator<llvm::symbolize::SymbolizableObjectFile::SymbolDesc *, std::vector<llvm::symbolize::SymbolizableObjectFile::SymbolDesc>>, llvm::symbolize::SymbolizableObjectFile::SymbolDesc>::_Temporary_buffer' requested here
 4996 |       _TmpBuf __buf(__first, (__last - __first + 1) / 2);
      |               ^
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_algo.h:5034:23: note: in instantiation of function template specialization 'std::__stable_sort<__gnu_cxx::__normal_iterator<llvm::symbolize::SymbolizableObjectFile::SymbolDesc *, std::vector<llvm::symbolize::SymbolizableObjectFile::SymbolDesc>>, __gnu_cxx::__ops::_Iter_less_iter>' requested here
 5034 |       _GLIBCXX_STD_A::__stable_sort(__first, __last,
      |                       ^
/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/include/llvm/ADT/STLExtras.h:2059:8: note: in instantiation of function template specialization 'std::stable_sort<__gnu_cxx::__normal_iterator<llvm::symbolize::SymbolizableObjectFile::SymbolDesc *, std::vector<llvm::symbolize::SymbolizableObjectFile::SymbolDesc>>>' requested here
 2059 |   std::stable_sort(adl_begin(Range), adl_end(Range));
      |        ^
/b/ml-opt-dev-x86-64-b1/llvm-project/llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp:76:9: note: in instantiation of function template specialization 'llvm::stable_sort<std::vector<llvm::symbolize::SymbolizableObjectFile::SymbolDesc> &>' requested here
   76 |   llvm::stable_sort(SS);
      |         ^
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/c++/12/bits/stl_tempbuf.h:99:5: note: 'get_temporary_buffer<llvm::symbolize::SymbolizableObjectFile::SymbolDesc>' has been explicitly marked deprecated here
   99 |     _GLIBCXX17_DEPRECATED
      |     ^
/usr/lib/gcc/x86_64-linux-gnu/12/../../../../include/x86_64-linux-gnu/c++/12/bits/c++config.h:119:34: note: expanded from macro '_GLIBCXX17_DEPRECATED'
  119 | # define _GLIBCXX17_DEPRECATED [[__deprecated__]]
      |                                  ^
1 warning generated.
23.546 [1943/62/1954] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/ELF_x86_64.cpp.o
23.546 [1943/61/1955] Building CXX object lib/ExecutionEngine/JITLink/CMakeFiles/LLVMJITLink.dir/COFF.cpp.o

```

</details>

https://github.com/llvm/llvm-project/pull/165841