[llvm] Reland [VPlan] Handle WidenGEP in narrowToSingleScalars (PR #167880)

Thu Nov 27 04:11:24 PST 2025

antmox wrote:

Hi @artagnon , @fhahn , could this path be the cause of clang-armv7-2stage and clang-armv8-lld-2stage bots failures ?
https://lab.llvm.org/buildbot/#/builders/79/builds/2444
https://lab.llvm.org/buildbot/#/builders/122/builds/2337

> FAILED: lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/Local.cpp.o 
> /home/tcwg-buildbot/worker/clang-armv8-lld-2stage/stage1.install/bin/clang++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_FILE_OFFSET_BITS=64 -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/stage2/lib/Transforms/Utils -I/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/llvm/llvm/lib/Transforms/Utils -I/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/stage2/include -I/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/llvm/llvm/include -mcpu=neoverse-n1 -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 -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/Local.cpp.o -MF lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/Local.cpp.o.d -o lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/Local.cpp.o -c /home/tcwg-buildbot/worker/clang-armv8-lld-2stage/llvm/llvm/lib/Transforms/Utils/Local.cpp
> clang++: ../llvm/llvm/lib/Transforms/Vectorize/VPlanTransforms.cpp:3451: void expandVPWidenPointerInduction(VPWidenPointerInductionRecipe *, VPTypeAnalysis &): Assertion `!R->onlyScalarsGenerated(Plan->hasScalableVF()) && "Recipe should have been replaced"' failed.
> PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
> Stack dump:
> 0.	Program arguments: /home/tcwg-buildbot/worker/clang-armv8-lld-2stage/stage1.install/bin/clang++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D_FILE_OFFSET_BITS=64 -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/stage2/lib/Transforms/Utils -I/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/llvm/llvm/lib/Transforms/Utils -I/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/stage2/include -I/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/llvm/llvm/include -mcpu=neoverse-n1 -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 -std=c++17 -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/Local.cpp.o -MF lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/Local.cpp.o.d -o lib/Transforms/Utils/CMakeFiles/LLVMTransformUtils.dir/Local.cpp.o -c /home/tcwg-buildbot/worker/clang-armv8-lld-2stage/llvm/llvm/lib/Transforms/Utils/Local.cpp
> 1.	<eof> parser at end of file
> 2.	Optimizer
> 3.	Running pass "function<eager-inv>(drop-unnecessary-assumes,float2int,lower-constant-intrinsics,chr,loop(loop-rotate<header-duplication;no-prepare-for-lto>,loop-deletion),loop-distribute,inject-tli-mappings,loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>,drop-unnecessary-assumes,infer-alignment,loop-load-elim,instcombine<max-iterations=1;no-verify-fixpoint>,simplifycfg<bonus-inst-threshold=1;forward-switch-cond;switch-range-to-icmp;switch-to-arithmetic;switch-to-lookup;no-keep-loops;hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,slp-vectorizer,vector-combine,instcombine<max-iterations=1;no-verify-fixpoint>,loop-unroll<O3>,transform-warning,sroa<preserve-cfg>,infer-alignment,instcombine<max-iterations=1;no-verify-fixpoint>,loop-mssa(licm<allowspeculation>),alignment-from-assumptions,loop-sink,instsimplify,div-rem-pairs,tailcallelim,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;switch-to-arithmetic;no-switch-to-lookup;keep-loops;no-hoist-common-insts;hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;speculate-unpredictables>)" on module "/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/llvm/llvm/lib/Transforms/Utils/Local.cpp"
> 4.	Running pass "loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>" on function "_ZN4llvm7hashing6detail23hash_combine_range_implINS_4User17value_op_iteratorEEENS_9hash_codeET_S6_"
> #0 0x1692ac7c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/stage1.install/bin/clang+++0x839ac7c)
> #1 0x169283b0 llvm::sys::RunSignalHandlers() (/home/tcwg-buildbot/worker/clang-armv8-lld-2stage/stage1.install/bin/clang+++0x83983b0)
> #2 0x16882454 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
> #3 0xea07d6e0 __default_sa_restorer ./signal/../sysdeps/unix/sysv/linux/arm/sigrestorer.S:67:0
> #4 0xea06db06 ./csu/../sysdeps/unix/sysv/linux/arm/libc-do-syscall.S:47:0
> #5 0xea0ad292 __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
> #6 0xea07c840 gsignal ./signal/../sysdeps/posix/raise.c:27:6
> clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
> clang version 22.0.0git (https://github.com/llvm/llvm-project.git f581d8ad8f0cd08da6465c6843f9c6841d49e522)
> Target: armv8l-unknown-linux-gnueabihf
> Thread model: posix
> InstalledDir: /home/tcwg-buildbot/worker/clang-armv8-lld-2stage/stage1.install/bin
> Build config: +assertions
> clang++: note: diagnostic msg: 
> ********************
> 

https://github.com/llvm/llvm-project/pull/167880