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

Sun Aug 24 02:15:01 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-lld-multistage-test` running on `ppc64le-lld-multistage-test` while building `llvm` at step 12 "build-stage2-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/168/builds/15535

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

```
Step 12 (build-stage2-unified-tree) failure: build (failure)
...
14.759 [1/8/16] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/ClangASTPropertiesEmitter.cpp.o
16.396 [1/7/17] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/ClangOptionDocEmitter.cpp.o
23.361 [1/6/18] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/ClangOpenCLBuiltinEmitter.cpp.o
31.941 [1/5/19] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/RISCVVEmitter.cpp.o
35.671 [1/4/20] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/SveEmitter.cpp.o
52.751 [1/3/21] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/MveEmitter.cpp.o
62.424 [1/2/22] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/NeonEmitter.cpp.o
99.998 [1/1/23] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/ClangAttrEmitter.cpp.o
100.066 [0/1/24] Linking CXX executable bin/clang-tblgen
136.130 [4085/671/1906] 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/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/install/stage1/bin/clang++ -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/home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage2/lib/Transforms/Vectorize -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/lib/Transforms/Vectorize -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/build/stage2/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/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  -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-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
/home/buildbots/llvm-external-buildbots/workers/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/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-lld-multistage-test/ppc64le-lld-multistage-test/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-lld-multistage-test/ppc64le-lld-multistage-test/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.
179.759 [4085/55/2522] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/MathExtrasTest.cpp.o
179.821 [4085/53/2524] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/VirtualFileSystemTest.cpp.o
179.866 [4085/52/2525] Building CXX object lib/Transforms/IPO/CMakeFiles/LLVMipo.dir/LowerTypeTests.cpp.o
179.890 [4085/51/2526] Building CXX object lib/DWARFLinker/Classic/CMakeFiles/LLVMDWARFLinkerClassic.dir/DWARFLinker.cpp.o
179.934 [4085/50/2527] Building CXX object lib/CodeGen/GlobalISel/CMakeFiles/LLVMGlobalISel.dir/IRTranslator.cpp.o
179.977 [4085/49/2528] Building CXX object unittests/IR/CMakeFiles/IRTests.dir/ConstantRangeTest.cpp.o
180.166 [4085/48/2529] Building CXX object lib/CodeGen/SelectionDAG/CMakeFiles/LLVMSelectionDAG.dir/TargetLowering.cpp.o
180.614 [4085/47/2530] Building CXX object unittests/Transforms/Instrumentation/CMakeFiles/InstrumentationTests.dir/MemProfUseTest.cpp.o
180.784 [4085/46/2531] Building CXX object lib/Transforms/IPO/CMakeFiles/LLVMipo.dir/WholeProgramDevirt.cpp.o
180.834 [4085/45/2532] Building CXX object unittests/IR/CMakeFiles/IRTests.dir/PatternMatch.cpp.o
181.068 [4085/44/2533] Building CXX object lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/AsmPrinter.cpp.o
181.136 [4085/43/2534] Building CXX object lib/Transforms/Scalar/CMakeFiles/LLVMScalarOpts.dir/LoopStrengthReduce.cpp.o
181.454 [4085/42/2535] Building CXX object lib/AsmParser/CMakeFiles/LLVMAsmParser.dir/LLParser.cpp.o
181.612 [4085/41/2536] Building CXX object lib/CodeGen/GlobalISel/CMakeFiles/LLVMGlobalISel.dir/CombinerHelper.cpp.o
181.636 [4085/40/2537] Building CXX object lib/CodeGen/AsmPrinter/CMakeFiles/LLVMAsmPrinter.dir/CodeViewDebug.cpp.o
182.107 [4085/39/2538] Building CXX object unittests/ProfileData/CMakeFiles/ProfileDataTests.dir/MemProfTest.cpp.o
182.243 [4085/38/2539] Building CXX object lib/Transforms/IPO/CMakeFiles/LLVMipo.dir/SampleProfile.cpp.o
182.317 [4085/37/2540] Building CXX object lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/SimplifyCFG.cpp.o
182.386 [4085/36/2541] Building CXX object lib/Object/CMakeFiles/LLVMObject.dir/ELF.cpp.o
182.643 [4085/35/2542] Building CXX object lib/Transforms/Vectorize/CMakeFiles/LLVMVectorize.dir/VPlanTransforms.cpp.o
182.799 [4085/34/2543] Building CXX object lib/ObjCopy/CMakeFiles/LLVMObjCopy.dir/ELF/ELFObject.cpp.o
183.710 [4085/33/2544] Building CXX object unittests/Transforms/Vectorize/CMakeFiles/VectorizeTests.dir/VPlanTest.cpp.o
184.269 [4085/32/2545] Building CXX object unittests/TargetParser/CMakeFiles/TargetParserTests.dir/TargetParserTest.cpp.o
184.539 [4085/31/2546] Building CXX object tools/llvm-profdata/CMakeFiles/llvm-profdata.dir/llvm-profdata.cpp.o
184.597 [4085/30/2547] Building CXX object unittests/IR/CMakeFiles/IRTests.dir/MetadataTest.cpp.o

```

</details>

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