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

Wed Nov 5 10:16:12 PST 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-win-fast` running on `as-builder-3` while building `llvm` at step 6 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/2/builds/37654

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

```
Step 6 (build-unified-tree) failure: build (failure)
...
[1450/4339] Building CXX object lib\Transforms\IPO\CMakeFiles\LLVMipo.dir\PartialInlining.cpp.obj
[1451/4339] Building CXX object lib\Transforms\IPO\CMakeFiles\LLVMipo.dir\StripSymbols.cpp.obj
[1452/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\Interval.cpp.obj
[1453/4339] Building CXX object lib\Transforms\Coroutines\CMakeFiles\LLVMCoroutines.dir\CoroConditionalWrapper.cpp.obj
[1454/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\LoadStoreVectorizer.cpp.obj
[1455/4339] Building CXX object lib\Transforms\Coroutines\CMakeFiles\LLVMCoroutines.dir\Coroutines.cpp.obj
[1456/4339] Building CXX object lib\Transforms\ObjCARC\CMakeFiles\LLVMObjCARCOpts.dir\ProvenanceAnalysis.cpp.obj
[1457/4339] Building CXX object lib\Transforms\ObjCARC\CMakeFiles\LLVMObjCARCOpts.dir\DependencyAnalysis.cpp.obj
[1458/4339] Building CXX object lib\Transforms\ObjCARC\CMakeFiles\LLVMObjCARCOpts.dir\ObjCARCContract.cpp.obj
[1459/4339] Building CXX object lib\CodeGen\CMakeFiles\LLVMCodeGen.dir\AtomicExpandPass.cpp.obj
FAILED: lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/AtomicExpandPass.cpp.obj 
C:\ninja\ccache.exe C:\PROGRA~1\MICROS~2\2022\COMMUN~1\VC\Tools\MSVC\1444~1.352\bin\Hostx64\x64\cl.exe  /nologo /TP -DGTEST_HAS_RTTI=0 -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_HAS_EXCEPTIONS=0 -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -IC:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\build\lib\CodeGen -IC:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\llvm-project\llvm\lib\CodeGen -IC:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\build\include -IC:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\llvm-project\llvm\include /DWIN32 /D_WINDOWS   /Zc:inline /Zc:preprocessor /Zc:__cplusplus /Oi /bigobj /permissive- /W4 -wd4141 -wd4146 -wd4244 -wd4267 -wd4291 -wd4351 -wd4456 -wd4457 -wd4458 -wd4459 -wd4503 -wd4624 -wd4722 -wd4100 -wd4127 -wd4512 -wd4505 -wd4610 -wd4510 -wd4702 -wd4245 -wd4706 -wd4310 -wd4701 -wd4703 -wd4389 -wd4611 -wd4805 -wd4204 -wd4577 -wd4091 -wd4592 -wd4319 -wd4709 -wd5105 -wd4324 -wd4251 -wd4275 -w14062 -we4238 /Gw /O2 /Ob2 /DNDEBUG -MD  /EHs-c- /GR- -std:c++17 /showIncludes /Folib\CodeGen\CMakeFiles\LLVMCodeGen.dir\AtomicExpandPass.cpp.obj /Fdlib\CodeGen\CMakeFiles\LLVMCodeGen.dir\LLVMCodeGen.pdb /FS -c C:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\llvm-project\llvm\lib\CodeGen\AtomicExpandPass.cpp
C:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\llvm-project\llvm\lib\CodeGen\AtomicExpandPass.cpp(1694): error C2664: 'void llvm::setExplicitlyUnknownBranchWeightsIfProfiled(llvm::Instruction &,llvm::StringRef,const llvm::Function *)': cannot convert argument 2 from 'llvm::Function' to 'llvm::StringRef'
C:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\llvm-project\llvm\lib\CodeGen\AtomicExpandPass.cpp(1694): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
C:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\llvm-project\llvm\include\llvm/IR/ProfDataUtils.h(200): note: see declaration of 'llvm::setExplicitlyUnknownBranchWeightsIfProfiled'
C:\buildbot\as-builder-3\llvm-clang-x86_64-win-fast\llvm-project\llvm\lib\CodeGen\AtomicExpandPass.cpp(1694): note: while trying to match the argument list '(llvm::Instruction, llvm::Function, const char [14])'
[1460/4339] Building CXX object lib\Transforms\ObjCARC\CMakeFiles\LLVMObjCARCOpts.dir\PtrState.cpp.obj
[1461/4339] Building CXX object lib\Transforms\IPO\CMakeFiles\LLVMipo.dir\SampleProfileProbe.cpp.obj
[1462/4339] Building CXX object lib\Transforms\ObjCARC\CMakeFiles\LLVMObjCARCOpts.dir\ObjCARCOpts.cpp.obj
[1463/4339] Building CXX object lib\Transforms\IPO\CMakeFiles\LLVMipo.dir\SCCP.cpp.obj
[1464/4339] Building CXX object lib\Transforms\ObjCARC\CMakeFiles\LLVMObjCARCOpts.dir\ObjCARC.cpp.obj
[1465/4339] Building CXX object lib\Transforms\IPO\CMakeFiles\LLVMipo.dir\OpenMPOpt.cpp.obj
[1466/4339] Building CXX object lib\Transforms\IPO\CMakeFiles\LLVMipo.dir\SampleProfileMatcher.cpp.obj
[1467/4339] Building CXX object lib\Transforms\IPO\CMakeFiles\LLVMipo.dir\SampleProfile.cpp.obj
[1468/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\LoopIdiomVectorize.cpp.obj
[1469/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\VPlanSLP.cpp.obj
[1470/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\VPlan.cpp.obj
[1471/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\VectorCombine.cpp.obj
[1472/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\VPlanUtils.cpp.obj
[1473/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\VPlanAnalysis.cpp.obj
[1474/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\VPlanUnroll.cpp.obj
[1475/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\VPlanRecipes.cpp.obj
[1476/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\VPlanVerifier.cpp.obj
[1477/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\LoopVectorizationLegality.cpp.obj
[1478/4339] Building CXX object lib\Transforms\IPO\CMakeFiles\LLVMipo.dir\WholeProgramDevirt.cpp.obj
[1479/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\DependencyGraph.cpp.obj
[1480/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\InstrMaps.cpp.obj
[1481/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\VecUtils.cpp.obj
[1482/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\Legality.cpp.obj
[1483/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\SandboxVectorizerPassBuilder.cpp.obj
[1484/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\VPlanPredicator.cpp.obj
[1485/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\Passes\RegionsFromBBs.cpp.obj
[1486/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\Passes\RegionsFromMetadata.cpp.obj
[1487/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SLPVectorizer.cpp.obj
[1488/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\Passes\PackReuse.cpp.obj
[1489/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\Passes\TransactionAcceptOrRevert.cpp.obj
[1490/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\SandboxVectorizer\Passes\BottomUpVec.cpp.obj
[1491/4339] Building CXX object lib\Transforms\IPO\CMakeFiles\LLVMipo.dir\ThinLTOBitcodeWriter.cpp.obj
[1492/4339] Building CXX object lib\Transforms\Vectorize\CMakeFiles\LLVMVectorize.dir\LoopVectorize.cpp.obj

```

</details>

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