[llvm] [VectorCombine] New folding pattern for extract/binop/shuffle chains (PR #145232)

Sun Aug 24 02:31:07 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64le-rhel` running on `ppc64le-clang-rhel-test` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/145/builds/9280

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
27.445 [403/101/164] Building CXX object lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/LCSSA.cpp.o
27.555 [403/100/165] Building CXX object lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/LoopVersioning.cpp.o
27.710 [403/99/166] Building CXX object lib/Transforms/Scalar/CMakeFiles/LLVMScalarOpts.dir/LoopTermFold.cpp.o
27.946 [403/98/167] Building CXX object unittests/Analysis/InlineOrderPlugin/CMakeFiles/InlineOrderPlugin.dir/InlineOrderPlugin.cpp.o
28.028 [402/98/168] Linking CXX shared module unittests/Analysis/InlineOrderPlugin.so
28.151 [402/97/169] Building CXX object lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/LoopConstrainer.cpp.o
28.473 [402/96/170] Building CXX object lib/ExecutionEngine/Orc/CMakeFiles/LLVMOrcJIT.dir/SpeculateAnalyses.cpp.o
28.638 [402/95/171] Building CXX object lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/LoopUnrollRuntime.cpp.o
28.727 [402/94/172] Building CXX object lib/Transforms/Scalar/CMakeFiles/LLVMScalarOpts.dir/LoopDeletion.cpp.o
28.737 [402/93/173] Building CXX object lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/VectorCombine.cpp.o
FAILED: lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/VectorCombine.cpp.o 
ccache /home/buildbots/llvm-external-buildbots/clang.19.1.7/bin/clang++ --gcc-toolchain=/gcc-toolchain/usr -DGTEST_HAS_RTTI=0 -DLLVM_EXPORTS -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/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/lib/Transforms/Vectorize -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Transforms/Vectorize -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror -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 -std=c++17 -fPIC  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/VectorCombine.cpp.o -MF lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/VectorCombine.cpp.o.d -o lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/VectorCombine.cpp.o -c /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Transforms/Vectorize/VectorCombine.cpp:4491:7: error: unannotated fall-through between switch labels [-Werror,-Wimplicit-fallthrough]
 4491 |       case Instruction::ICmp:
      |       ^
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Transforms/Vectorize/VectorCombine.cpp:4491:7: note: insert 'LLVM_FALLTHROUGH;' to silence this warning
 4491 |       case Instruction::ICmp:
      |       ^
      |       LLVM_FALLTHROUGH; 
/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Transforms/Vectorize/VectorCombine.cpp:4491:7: note: insert 'break;' to avoid fall-through
 4491 |       case Instruction::ICmp:
      |       ^
      |       break; 
1 error generated.
28.752 [402/92/174] Building CXX object lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/LoopSimplify.cpp.o
28.896 [402/91/175] Building CXX object tools/clang/tools/clang-fuzzer/handle-llvm/CMakeFiles/obj.clangHandleLLVM.dir/handle_llvm.cpp.o
29.944 [402/90/176] Building CXX object examples/IRTransforms/CMakeFiles/ExampleIRTransforms.dir/SimplifyCFG.cpp.o
30.113 [402/89/177] Building CXX object tools/llvm-reduce/CMakeFiles/llvm-reduce.dir/deltas/RunIRPasses.cpp.o
30.477 [402/88/178] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTOModule.cpp.o
30.500 [402/87/179] Building CXX object lib/Transforms/Scalar/CMakeFiles/LLVMScalarOpts.dir/LoopUnrollPass.cpp.o
30.872 [402/86/180] Building CXX object lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/SimplifyIndVar.cpp.o
30.984 [402/85/181] Building CXX object lib/Target/ARM/CMakeFiles/LLVMARMCodeGen.dir/ARMSelectionDAGInfo.cpp.o
31.091 [402/84/182] Building CXX object lib/Target/AVR/CMakeFiles/LLVMAVRCodeGen.dir/AVRTargetTransformInfo.cpp.o
31.386 [402/83/183] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/LTOCodeGenerator.cpp.o
31.504 [402/82/184] Building CXX object lib/Target/LoongArch/CMakeFiles/LLVMLoongArchCodeGen.dir/LoongArchTargetMachine.cpp.o
31.554 [402/81/185] Building CXX object lib/Target/SystemZ/CMakeFiles/LLVMSystemZCodeGen.dir/SystemZTargetTransformInfo.cpp.o
31.595 [402/80/186] Building CXX object lib/Transforms/Scalar/CMakeFiles/LLVMScalarOpts.dir/LoopLoadElimination.cpp.o
31.602 [402/79/187] Building CXX object lib/Target/Lanai/CMakeFiles/LLVMLanaiCodeGen.dir/LanaiTargetMachine.cpp.o
31.644 [402/78/188] Building CXX object lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/LoopUnrollAndJam.cpp.o
31.699 [402/77/189] Building CXX object lib/Transforms/Scalar/CMakeFiles/LLVMScalarOpts.dir/LoopDistribute.cpp.o
32.156 [402/76/190] Building CXX object lib/Transforms/Scalar/CMakeFiles/LLVMScalarOpts.dir/LoopFlatten.cpp.o
32.596 [402/75/191] Building CXX object lib/Transforms/Scalar/CMakeFiles/LLVMScalarOpts.dir/LowerMatrixIntrinsics.cpp.o
32.819 [402/74/192] Building CXX object lib/Target/SystemZ/CMakeFiles/LLVMSystemZCodeGen.dir/SystemZTargetMachine.cpp.o
33.107 [402/73/193] Building CXX object lib/Passes/CMakeFiles/LLVMPasses.dir/PassBuilderBindings.cpp.o
33.306 [402/72/194] Building CXX object lib/CodeGen/CMakeFiles/LLVMCodeGen.dir/BasicTargetTransformInfo.cpp.o
33.429 [402/71/195] Building CXX object lib/Target/Hexagon/CMakeFiles/LLVMHexagonCodeGen.dir/HexagonLoopIdiomRecognition.cpp.o
33.731 [402/70/196] Building CXX object lib/Target/VE/CMakeFiles/LLVMVECodeGen.dir/VETargetMachine.cpp.o
33.760 [402/69/197] Building CXX object lib/Target/X86/CMakeFiles/LLVMX86CodeGen.dir/X86InstCombineIntrinsic.cpp.o
33.811 [402/68/198] Building CXX object tools/llvm-extract/CMakeFiles/llvm-extract.dir/llvm-extract.cpp.o

```

</details>

https://github.com/llvm/llvm-project/pull/145232