[PATCH] D127531: [SLP]Improve analysis of same/alternate code ops and scheduling.

Mon Oct 31 07:51:35 PDT 2022

ABataev added a comment.

In D127531#3896257 <https://reviews.llvm.org/D127531#3896257>, @uabelho wrote:

> Hello,
>
> The following starts crashing with this patch:
>  opt --passes=slp-vectorizer bbi-75302.ll -o /dev/null
>
> I get
>
>   opt: ../include/llvm/ADT/ArrayRef.h:256: const T &llvm::ArrayRef<llvm::Value *>::operator[](size_t) const [T = llvm::Value *]: Assertion `Index < Length && "Invalid index!"' failed.
>   PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
>   Stack dump:
>   0.	Program arguments: build-all/bin/opt --passes=slp-vectorizer /home/uabelho/bbi-75302.ll -o /dev/null
>    #0 0x0000000002e58093 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (build-all/bin/opt+0x2e58093)
>    #1 0x0000000002e55dae llvm::sys::RunSignalHandlers() (build-all/bin/opt+0x2e55dae)
>    #2 0x0000000002e58416 SignalHandler(int) (build-all/bin/opt+0x2e58416)
>    #3 0x00007ff50079f630 __restore_rt (/lib64/libpthread.so.0+0xf630)
>    #4 0x00007ff4fdee6387 raise (/lib64/libc.so.6+0x36387)
>    #5 0x00007ff4fdee7a78 abort (/lib64/libc.so.6+0x37a78)
>    #6 0x00007ff4fdedf1a6 __assert_fail_base (/lib64/libc.so.6+0x2f1a6)
>    #7 0x00007ff4fdedf252 (/lib64/libc.so.6+0x2f252)
>    #8 0x0000000002f40627 (build-all/bin/opt+0x2f40627)
>    #9 0x00000000030ae5b2 llvm::slpvectorizer::BoUpSLP::vectorizeTree(llvm::slpvectorizer::BoUpSLP::TreeEntry*) (build-all/bin/opt+0x30ae5b2)
>   #10 0x00000000030aa658 llvm::slpvectorizer::BoUpSLP::vectorizeTree(llvm::ArrayRef<llvm::Value*>) (build-all/bin/opt+0x30aa658)
>   #11 0x00000000030ab1e7 llvm::slpvectorizer::BoUpSLP::vectorizeTree(llvm::slpvectorizer::BoUpSLP::TreeEntry*) (build-all/bin/opt+0x30ab1e7)
>   #12 0x00000000030b2659 llvm::slpvectorizer::BoUpSLP::vectorizeTree(llvm::MapVector<llvm::Value*, llvm::SmallVector<llvm::Instruction*, 2u>, llvm::DenseMap<llvm::Value*, unsigned int, llvm::DenseMapInfo<llvm::Value*, void>, llvm::detail::DenseMapPair<llvm::Value*, unsigned int> >, std::vector<std::pair<llvm::Value*, llvm::SmallVector<llvm::Instruction*, 2u> >, std::allocator<std::pair<llvm::Value*, llvm::SmallVector<llvm::Instruction*, 2u> > > > >&) (build-all/bin/opt+0x30b2659)
>   #13 0x00000000030d9d6f (anonymous namespace)::HorizontalReduction::tryToReduce(llvm::slpvectorizer::BoUpSLP&, llvm::TargetTransformInfo*, llvm::TargetLibraryInfo const&) (build-all/bin/opt+0x30d9d6f)
>   #14 0x00000000030c7588 llvm::SLPVectorizerPass::vectorizeHorReduction(llvm::PHINode*, llvm::Value*, llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&, llvm::TargetTransformInfo*, llvm::SmallVectorImpl<llvm::WeakTrackingVH>&) (build-all/bin/opt+0x30c7588)
>   #15 0x00000000030c8969 llvm::SLPVectorizerPass::vectorizeRootInstruction(llvm::PHINode*, llvm::Value*, llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&, llvm::TargetTransformInfo*) (build-all/bin/opt+0x30c8969)
>   #16 0x00000000030bf821 llvm::SLPVectorizerPass::vectorizeChainsInBlock(llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&) (build-all/bin/opt+0x30bf821)
>   #17 0x00000000030bd85c llvm::SLPVectorizerPass::runImpl(llvm::Function&, llvm::ScalarEvolution*, llvm::TargetTransformInfo*, llvm::TargetLibraryInfo*, llvm::AAResults*, llvm::LoopInfo*, llvm::DominatorTree*, llvm::AssumptionCache*, llvm::DemandedBits*, llvm::OptimizationRemarkEmitter*) (build-all/bin/opt+0x30bd85c)
>   #18 0x00000000030bcbff llvm::SLPVectorizerPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (build-all/bin/opt+0x30bcbff)
>   #19 0x00000000031c7c4d llvm::detail::PassModel<llvm::Function, llvm::SLPVectorizerPass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (build-all/bin/opt+0x31c7c4d)
>   #20 0x000000000266850c llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (build-all/bin/opt+0x266850c)
>   #21 0x0000000000aefdbd llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function> >, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (build-all/bin/opt+0xaefdbd)
>   #22 0x000000000266c7ee llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (build-all/bin/opt+0x266c7ee)
>   #23 0x0000000000aefb9d llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (build-all/bin/opt+0xaefb9d)
>   #24 0x00000000026677bc llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (build-all/bin/opt+0x26677bc)
>   #25 0x0000000000721779 llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::StringRef>, llvm::ArrayRef<llvm::PassPlugin>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool) (build-all/bin/opt+0x721779)
>   #26 0x0000000000730c61 main (build-all/bin/opt+0x730c61)
>   #27 0x00007ff4fded2555 __libc_start_main (/lib64/libc.so.6+0x22555)
>   #28 0x000000000071a3e0 _start (build-all/bin/opt+0x71a3e0)
>   Abort
>
> F25137229: bbi-75302.ll <https://reviews.llvm.org/F25137229>

Not a bug in the patch itself, it revealed the issue in the existing code. Will send a patch in few minutes.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D127531/new/

https://reviews.llvm.org/D127531