[llvm] [SLP]Vectorize gathered loads (PR #107461)

[Mikael Holmén via llvm-commits]

mikaelholmen wrote:

Hi @alexey-bataev 

The following starts crashing with this patch:
```opt -passes=slp-vectorizer bbi-99793.ll -o /dev/null```
(I've run llvm-reduce but the input is unfortunately still quite large)

It crashes with
```
opt: ../lib/Transforms/Vectorize/SLPVectorizer.cpp:7568: void llvm::slpvectorizer::BoUpSLP::buildTree_rec(ArrayRef<llvm::Value *>, unsigned int, const llvm::slpvectorizer::BoUpSLP::EdgeInfo &): Assertion `(allConstant(VL) || allSameType(VL)) && "Invalid types!"' 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 bbi-99793.ll -o /dev/null
1.	Running pass "function(slp-vectorizer)" on module "bbi-99793.ll"
2.	Running pass "slp-vectorizer" on function "test_structcopy_14"
 #0 0x00005562edfca907 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (build-all/bin/opt+0x422b907)
 #1 0x00005562edfc83ee llvm::sys::RunSignalHandlers() (build-all/bin/opt+0x42293ee)
 #2 0x00005562edfcb12f SignalHandler(int) Signals.cpp:0:0
 #3 0x00007f3e3e628cf0 __restore_rt (/lib64/libpthread.so.0+0x12cf0)
 #4 0x00007f3e3c1e1acf raise (/lib64/libc.so.6+0x4eacf)
 #5 0x00007f3e3c1b4ea5 abort (/lib64/libc.so.6+0x21ea5)
 #6 0x00007f3e3c1b4d79 _nl_load_domain.cold.0 (/lib64/libc.so.6+0x21d79)
 #7 0x00007f3e3c1da426 (/lib64/libc.so.6+0x47426)
 #8 0x00005562ef8e84b6 llvm::slpvectorizer::BoUpSLP::buildTree_rec(llvm::ArrayRef<llvm::Value*>, unsigned int, llvm::slpvectorizer::BoUpSLP::EdgeInfo const&) (build-all/bin/opt+0x5b494b6)
 #9 0x00005562ef8e9fcd llvm::slpvectorizer::BoUpSLP::tryToVectorizeGatheredLoads(llvm::ArrayRef<llvm::SmallVector<std::pair<llvm::LoadInst*, int>, 3u>>)::$_41::operator()(llvm::ArrayRef<llvm::SmallVector<std::pair<llvm::LoadInst*, int>, 3u>>, bool) const SLPVectorizer.cpp:0:0
#10 0x00005562ef8e8a2b llvm::slpvectorizer::BoUpSLP::tryToVectorizeGatheredLoads(llvm::ArrayRef<llvm::SmallVector<std::pair<llvm::LoadInst*, int>, 3u>>) (build-all/bin/opt+0x5b49a2b)
#11 0x00005562ef8f84ca llvm::slpvectorizer::BoUpSLP::transformNodes() (build-all/bin/opt+0x5b594ca)
#12 0x00005562ef96153b (anonymous namespace)::HorizontalReduction::tryToReduce(llvm::slpvectorizer::BoUpSLP&, llvm::DataLayout const&, llvm::TargetTransformInfo*, llvm::TargetLibraryInfo const&) SLPVectorizer.cpp:0:0
#13 0x00005562ef93b1a8 llvm::SLPVectorizerPass::vectorizeHorReduction(llvm::PHINode*, llvm::Instruction*, llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&, llvm::TargetTransformInfo*, llvm::SmallVectorImpl<llvm::WeakTrackingVH>&) (build-all/bin/opt+0x5b9c1a8)
#14 0x00005562ef93b58b llvm::SLPVectorizerPass::vectorizeRootInstruction(llvm::PHINode*, llvm::Instruction*, llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&, llvm::TargetTransformInfo*) (build-all/bin/opt+0x5b9c58b)
#15 0x00005562ef93025d llvm::SLPVectorizerPass::vectorizeChainsInBlock(llvm::BasicBlock*, llvm::slpvectorizer::BoUpSLP&) (build-all/bin/opt+0x5b9125d)
#16 0x00005562ef92d1b0 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+0x5b8e1b0)
#17 0x00005562ef92c805 llvm::SLPVectorizerPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (build-all/bin/opt+0x5b8d805)
#18 0x00005562ef381e7d llvm::detail::PassModel<llvm::Function, llvm::SLPVectorizerPass, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) PassBuilderPipelines.cpp:0:0
#19 0x00005562ee1d51da llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (build-all/bin/opt+0x44361da)
#20 0x00005562ef37a1ed llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) PassBuilderPipelines.cpp:0:0
#21 0x00005562ee1d9ca1 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (build-all/bin/opt+0x443aca1)
#22 0x00005562ef373d8d llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) PassBuilderPipelines.cpp:0:0
#23 0x00005562ee1d3f1a llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (build-all/bin/opt+0x4434f1a)
#24 0x00005562ef31df5b llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::PassPlugin>, llvm::ArrayRef<std::function<void (llvm::PassBuilder&)>>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool) (build-all/bin/opt+0x557ef5b)
#25 0x00005562edf91f7d optMain (build-all/bin/opt+0x41f2f7d)
#26 0x00007f3e3c1cdd85 __libc_start_main (/lib64/libc.so.6+0x3ad85)
#27 0x00005562edf8baee _start (build-all/bin/opt+0x41ecaee)
Abort (core dumped)
```
[bbi-99793.ll.gz](https://github.com/user-attachments/files/17254626/bbi-99793.ll.gz)


https://github.com/llvm/llvm-project/pull/107461