[llvm] [AArch64][MachineCombiner] Reassociate long chains of accumulation instructions into a tree to increase ILP (PR #126060)

Sun Mar 23 04:32:29 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `openmp-gcc-x86_64-linux-debian` running on `gribozavr4` while building `llvm` at step 5 "compile-openmp".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/70/builds/7896

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

```
Step 5 (compile-openmp) failure: build (failure)
...
35.656 [2931/96/2472] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVElement.cpp.o
35.668 [2930/96/2473] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVLine.cpp.o
35.691 [2929/96/2474] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVLocation.cpp.o
35.693 [2928/96/2475] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVObject.cpp.o
35.706 [2927/96/2476] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVOptions.cpp.o
35.720 [2926/96/2477] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVReader.cpp.o
35.728 [2925/96/2478] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVScope.cpp.o
35.753 [2924/96/2479] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/MachineBasicBlock.cpp.o
35.764 [2923/96/2480] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/SwiftErrorValueTracking.cpp.o
35.788 [2922/96/2481] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/TargetInstrInfo.cpp.o
FAILED: lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/TargetInstrInfo.cpp.o 
CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/bin/ccache /usr/bin/clang++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/b/1/openmp-gcc-x86_64-linux-debian/llvm.build/lib/CodeGen -I/b/1/openmp-gcc-x86_64-linux-debian/llvm.src/llvm/lib/CodeGen -I/b/1/openmp-gcc-x86_64-linux-debian/llvm.build/include -I/b/1/openmp-gcc-x86_64-linux-debian/llvm.src/llvm/include -fPIC -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 -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/TargetInstrInfo.cpp.o -MF lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/TargetInstrInfo.cpp.o.d -o lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/TargetInstrInfo.cpp.o -c /b/1/openmp-gcc-x86_64-linux-debian/llvm.src/llvm/lib/CodeGen/TargetInstrInfo.cpp
/b/1/openmp-gcc-x86_64-linux-debian/llvm.src/llvm/lib/CodeGen/TargetInstrInfo.cpp:1514:29: error: non-const lvalue reference to type 'DenseMap<unsigned int, [...]>' cannot bind to a value of unrelated type 'DenseMap<llvm::Register, [...]>'
                            InstIdxForVirtReg, Root.getOperand(0).getReg());
                            ^~~~~~~~~~~~~~~~~
/b/1/openmp-gcc-x86_64-linux-debian/llvm.src/llvm/lib/CodeGen/TargetInstrInfo.cpp:1021:35: note: passing argument to parameter 'InstrIdxForVirtReg' here
    DenseMap<unsigned, unsigned> &InstrIdxForVirtReg,
                                  ^
1 error generated.
35.789 [2922/95/2482] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVRange.cpp.o
35.789 [2922/94/2483] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVSort.cpp.o
35.789 [2922/93/2484] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVSupport.cpp.o
35.790 [2922/92/2485] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVSymbol.cpp.o
35.790 [2922/91/2486] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Core/LVType.cpp.o
35.791 [2922/90/2487] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/LVReaderHandler.cpp.o
35.791 [2922/89/2488] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Readers/LVBinaryReader.cpp.o
35.792 [2922/88/2489] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Readers/LVCodeViewReader.cpp.o
35.792 [2922/87/2490] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Readers/LVCodeViewVisitor.cpp.o
35.792 [2922/86/2491] Building CXX object lib/DebugInfo/LogicalView/CMakeFiles/LLVMDebugInfoLogicalView.dir/Readers/LVDWARFReader.cpp.o
35.793 [2922/85/2492] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/GenericError.cpp.o
35.793 [2922/84/2493] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/IPDBSourceFile.cpp.o
35.793 [2922/83/2494] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDB.cpp.o
35.793 [2922/82/2495] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBContext.cpp.o
35.794 [2922/81/2496] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBExtras.cpp.o
35.794 [2922/80/2497] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBInterfaceAnchors.cpp.o
35.794 [2922/79/2498] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbol.cpp.o
35.794 [2922/78/2499] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolAnnotation.cpp.o
35.795 [2922/77/2500] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolBlock.cpp.o
35.795 [2922/76/2501] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolCompiland.cpp.o
35.795 [2922/75/2502] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolCompilandDetails.cpp.o
35.795 [2922/74/2503] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolCompilandEnv.cpp.o
35.796 [2922/73/2504] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolCustom.cpp.o
35.796 [2922/72/2505] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolData.cpp.o
35.796 [2922/71/2506] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolExe.cpp.o
35.796 [2922/70/2507] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolFunc.cpp.o
35.796 [2922/69/2508] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolFuncDebugEnd.cpp.o
35.797 [2922/68/2509] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolFuncDebugStart.cpp.o
35.797 [2922/67/2510] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolLabel.cpp.o
35.797 [2922/66/2511] Building CXX object lib/DebugInfo/PDB/CMakeFiles/LLVMDebugInfoPDB.dir/PDBSymbolPublicSymbol.cpp.o

```

</details>

https://github.com/llvm/llvm-project/pull/126060