[MemorySSA][LoopRotate] Assertion `!Paths.empty() && "Need a path to move"' failed. #139103

dtcxzyw · 2025-05-08T16:09:31Z

This is a recent regression (llvm version 37fecfa).
Reproducer: https://godbolt.org/z/9MGhvsKPb

> bin/opt -passes="loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<nontrivial;trivial>)" test.ll -S
opt: /data/zyw/llvm-project/llvm/lib/Analysis/MemorySSA.cpp:783: {anonymous}::ClobberWalker::tryOptimizePhi(llvm::MemoryPhi*, llvm::MemoryAccess*, const llvm::MemoryLocation&)::<lambda(llvm::SmallVectorImpl<{anonymous}::ClobberWalker::TerminatedPath>&)>: Assertion `!Paths.empty() && "Need a path to move"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: ../llvm-build/bin/opt -passes=loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<nontrivial;trivial>) test.ll -S
1.      Running pass "function(loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<nontrivial;trivial>))" on module "test.ll"
2.      Running pass "loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<nontrivial;trivial>)" on function "func_137"
 #0 0x00007ffff7dfebb2 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/data/zyw/llvm-build/bin/../lib/libLLVMSupport.so.21.0git+0x1febb2)
 #1 0x00007ffff7dfbd1f llvm::sys::RunSignalHandlers() (/data/zyw/llvm-build/bin/../lib/libLLVMSupport.so.21.0git+0x1fbd1f)
 #2 0x00007ffff7dfbe64 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x00007ffff7842520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x00007ffff78969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x00007ffff7842476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x00007ffff78287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x00007ffff782871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #8 0x00007ffff7839e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #9 0x00007ffff3f85027 (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMAnalysis.so.21.0git+0x385027)
#10 0x00007ffff3f88c30 (anonymous namespace)::ClobberWalker::findClobber(llvm::BatchAAResults&, llvm::MemoryAccess*, (anonymous namespace)::UpwardsMemoryQuery&, unsigned int&) MemorySSA.cpp:0:0
#11 0x00007ffff3f898cc llvm::MemorySSA::ClobberWalkerBase::getClobberingMemoryAccessBase(llvm::MemoryAccess*, llvm::BatchAAResults&, unsigned int&, bool, bool) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMAnalysis.so.21.0git+0x3898cc)
#12 0x00007ffff3f8b01a llvm::MemorySSA::SkipSelfWalker::getClobberingMemoryAccess(llvm::MemoryAccess*, llvm::BatchAAResults&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMAnalysis.so.21.0git+0x38b01a)
#13 0x00007ffff4f91e6a getClobberingMemoryAccess(llvm::MemorySSA&, llvm::BatchAAResults&, llvm::SinkAndHoistLICMFlags&, llvm::MemoryUseOrDef*) LICM.cpp:0:0
#14 0x00007ffff4f99055 llvm::canSinkOrHoistInst(llvm::Instruction&, llvm::AAResults*, llvm::DominatorTree*, llvm::Loop*, llvm::MemorySSAUpdater&, bool, llvm::SinkAndHoistLICMFlags&, llvm::OptimizationRemarkEmitter*) (.part.0) LICM.cpp:0:0
#15 0x00007ffff4fa223a llvm::hoistRegion(llvm::DomTreeNodeBase<llvm::BasicBlock>*, llvm::AAResults*, llvm::LoopInfo*, llvm::DominatorTree*, llvm::AssumptionCache*, llvm::TargetLibraryInfo*, llvm::Loop*, llvm::MemorySSAUpdater&, llvm::ScalarEvolution*, llvm::ICFLoopSafetyInfo*, llvm::SinkAndHoistLICMFlags&, llvm::OptimizationRemarkEmitter*, bool, bool) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMScalarOpts.so.21.0git+0x1a223a)
#16 0x00007ffff4fa72e0 (anonymous namespace)::LoopInvariantCodeMotion::runOnLoop(llvm::Loop*, llvm::AAResults*, llvm::LoopInfo*, llvm::DominatorTree*, llvm::AssumptionCache*, llvm::TargetLibraryInfo*, llvm::TargetTransformInfo*, llvm::ScalarEvolution*, llvm::MemorySSA*, llvm::OptimizationRemarkEmitter*, bool) (.part.0) LICM.cpp:0:0
#17 0x00007ffff4faa26c llvm::LICMPass::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMScalarOpts.so.21.0git+0x1aa26c)
#18 0x00007ffff66887f5 llvm::detail::PassModel<llvm::Loop, llvm::LICMPass, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMPasses.so.21.0git+0x887f5)
#19 0x00007ffff5018914 std::optional<llvm::PreservedAnalyses> llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runSinglePass<llvm::Loop, std::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>>>>(llvm::Loop&, std::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>>>&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&, llvm::PassInstrumentation&) (.isra.0) LoopPassManager.cpp:0:0
#20 0x00007ffff5019c80 llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runWithoutLoopNestPasses(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMScalarOpts.so.21.0git+0x219c80)
#21 0x00007ffff5019e3b llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMScalarOpts.so.21.0git+0x219e3b)
#22 0x00007ffff66886d5 llvm::detail::PassModel<llvm::Loop, llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMPasses.so.21.0git+0x886d5)
#23 0x00007ffff501b958 llvm::FunctionToLoopPassAdaptor::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMScalarOpts.so.21.0git+0x21b958)
#24 0x00007ffff70ad865 llvm::detail::PassModel<llvm::Function, llvm::FunctionToLoopPassAdaptor, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMX86CodeGen.so.21.0git+0xad865)
#25 0x00007ffff3909a1d llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMCore.so.21.0git+0x309a1d)
#26 0x00007ffff70ad135 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMX86CodeGen.so.21.0git+0xad135)
#27 0x00007ffff39078d0 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMCore.so.21.0git+0x3078d0)
#28 0x00007ffff70adaf5 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMX86CodeGen.so.21.0git+0xadaf5)
#29 0x00007ffff390857d llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/data/zyw/llvm-build/bin/../lib/../lib/libLLVMCore.so.21.0git+0x30857d)
#30 0x00007ffff7f9ba9b 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) (/data/zyw/llvm-build/bin/../lib/libLLVMOptDriver.so.21.0git+0x23a9b)
#31 0x00007ffff7fa58ed optMain (/data/zyw/llvm-build/bin/../lib/libLLVMOptDriver.so.21.0git+0x2d8ed)
#32 0x00007ffff7829d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#33 0x00007ffff7829e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#34 0x0000555555555095 _start (../llvm-build/bin/opt+0x1095)
Aborted (core dumped)

The text was updated successfully, but these errors were encountered:

dtcxzyw · 2025-05-08T17:01:12Z

Reduced:

; bin/opt -passes="loop-mssa(licm,loop-rotate,licm,simple-loop-unswitch<nontrivial>)" -verify-memoryssa test.ll -S
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

define void @func_137(i1 %0) {
entry:
  br label %for.cond9

for.cond9:                                        ; preds = %for.inc519, %entry
  br i1 false, label %for.end521, label %for.cond23

for.cond23:                                       ; preds = %if.else229, %for.cond9
  %l_1344.1 = phi i32 [ %conv50, %if.else229 ], [ 0, %for.cond9 ]
  br i1 true, label %for.end494, label %for.cond29

for.cond29:                                       ; preds = %for.cond23
  store i32 0, ptr null, align 4
  %1 = load i32, ptr null, align 4
  %conv50 = xor i32 %1, %l_1344.1
  br i1 %0, label %if.else229, label %if.then204

if.then204:                                       ; preds = %for.cond29
  ret void

if.else229:                                       ; preds = %for.cond29
  br label %for.cond23

for.end494:                                       ; preds = %for.cond23
  br i1 false, label %for.inc519, label %for.end521

for.inc519:                                       ; preds = %for.end494
  br label %for.cond9

for.end521:                                       ; preds = %for.end494, %for.cond9
  ret void
}

opt: /home/dtcxzyw/WorkSpace/Projects/compilers/llvm-project/llvm/lib/Analysis/MemorySSA.cpp:2067: void llvm::MemorySSA::verifyOrderingDominationAndDefUses(IterT, VerificationLevel) const [with IterT = llvm::iterator_range<llvm::ilist_iterator<llvm::ilist_detail::node_options<llvm::BasicBlock, false, false, void, false, void>, false, false> >]: Assertion `dominates(MD, U) && "Memory Def does not dominate it's uses"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: bin/opt -passes=loop-mssa(licm,loop-rotate,licm,simple-loop-unswitch<nontrivial>) -verify-memoryssa test.ll -S
1.      Running pass "function(loop-mssa(licm<allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<nontrivial;trivial>))" on module "test.ll"
2.      Running pass "loop-mssa(licm<allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<nontrivial;trivial>)" on function "func_137"
 #0 0x00007dd7dd025f52 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/libLLVMSupport.so.21.0git+0x225f52)
 #1 0x00007dd7dd022e2f llvm::sys::RunSignalHandlers() (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/libLLVMSupport.so.21.0git+0x222e2f)
 #2 0x00007dd7dd022f74 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x00007dd7dca45330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
 #4 0x00007dd7dca9eb2c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 #5 0x00007dd7dca9eb2c __pthread_kill_internal ./nptl/pthread_kill.c:78:10
 #6 0x00007dd7dca9eb2c pthread_kill ./nptl/pthread_kill.c:89:10
 #7 0x00007dd7dca4527e raise ./signal/../sysdeps/posix/raise.c:27:6
 #8 0x00007dd7dca288ff abort ./stdlib/abort.c:81:7
 #9 0x00007dd7dca2881b _nl_load_domain ./intl/loadmsgcat.c:1177:9
#10 0x00007dd7dca3b517 (/lib/x86_64-linux-gnu/libc.so.6+0x3b517)
#11 0x00007dd7d43b84ef void llvm::MemorySSA::verifyOrderingDominationAndDefUses<llvm::iterator_range<llvm::ilist_iterator<llvm::ilist_detail::node_options<llvm::BasicBlock, false, false, void, false, void>, false, false>>>(llvm::iterator_range<llvm::ilist_iterator<llvm::ilist_detail::node_options<llvm::BasicBlock, false, false, void, false, void>, false, false>>, llvm::MemorySSA::VerificationLevel) const (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMAnalysis.so.21.0git+0x3b84ef)
#12 0x00007dd7d43b8c11 llvm::MemorySSA::verifyMemorySSA(llvm::MemorySSA::VerificationLevel) const (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMAnalysis.so.21.0git+0x3b8c11)
#13 0x00007dd7d49c96ce (anonymous namespace)::LoopRotate::rotateLoop(llvm::Loop*, bool) LoopRotationUtils.cpp:0:0
#14 0x00007dd7d49c9fbf llvm::LoopRotation(llvm::Loop*, llvm::LoopInfo*, llvm::TargetTransformInfo const*, llvm::AssumptionCache*, llvm::DominatorTree*, llvm::ScalarEvolution*, llvm::MemorySSAUpdater*, llvm::SimplifyQuery const&, bool, unsigned int, bool, bool) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMTransformUtils.so.21.0git+0x1c9fbf)
#15 0x00007dd7d583ff34 llvm::LoopRotatePass::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMScalarOpts.so.21.0git+0x23ff34)
#16 0x00007dd7d73ac765 llvm::detail::PassModel<llvm::Loop, llvm::LoopRotatePass, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libPolly.so.21.0git+0x1ac765)
#17 0x00007dd7d5834aed llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runWithoutLoopNestPasses(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMScalarOpts.so.21.0git+0x234aed)
#18 0x00007dd7d583459c llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMScalarOpts.so.21.0git+0x23459c)
#19 0x00007dd7d73ac815 llvm::detail::PassModel<llvm::Loop, llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libPolly.so.21.0git+0x1ac815)
#20 0x00007dd7d5836395 llvm::FunctionToLoopPassAdaptor::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMScalarOpts.so.21.0git+0x236395)
#21 0x00007dd7dbcdaa45 llvm::detail::PassModel<llvm::Function, llvm::FunctionToLoopPassAdaptor, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMX86CodeGen.so.21.0git+0xdaa45)
#22 0x00007dd7d3d2a494 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMCore.so.21.0git+0x32a494)
#23 0x00007dd7dbcda315 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMX86CodeGen.so.21.0git+0xda315)
#24 0x00007dd7d3d28d70 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMCore.so.21.0git+0x328d70)
#25 0x00007dd7dbcdacd5 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMX86CodeGen.so.21.0git+0xdacd5)
#26 0x00007dd7d3d29365 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/../lib/libLLVMCore.so.21.0git+0x329365)
#27 0x00007dd7dd2712e9 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) (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/libLLVMOptDriver.so.21.0git+0x2c2e9)
#28 0x00007dd7dd27c306 optMain (/home/dtcxzyw/WorkSpace/Projects/compilers/LLVM/llvm-build/bin/../lib/libLLVMOptDriver.so.21.0git+0x37306)
#29 0x00007dd7dca2a1ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#30 0x00007dd7dca2a28b call_init ./csu/../csu/libc-start.c:128:20
#31 0x00007dd7dca2a28b __libc_start_main ./csu/../csu/libc-start.c:347:5
#32 0x000063062f7cd095 _start (bin/opt+0x1095)

Aborted (core dumped)

dtcxzyw · 2025-05-09T14:25:05Z

Bisected to 4d60c6d
cc @arsenm @nikic

dtcxzyw · 2025-05-09T14:33:38Z

Another reproducer:

; bin/opt -passes="loop-mssa(licm,loop-rotate,licm,simple-loop-unswitch<nontrivial>)" -verify-memoryssa test.ll -S
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

define void @test(ptr %p, i1 %cond) {
entry:
  br label %for.header

for.header:
  br i1 false, label %exit.loopexit1, label %for.header2.preheader

for.header2.preheader:
  br label %for.body

for.header2:
  br i1 false, label %for.latch, label %for.body

for.body:
  store i32 0, ptr %p, align 4
  store i8 0, ptr %p, align 1
  br i1 %cond, label %for.header2, label %exit.loopexit

for.latch:
  br i1 false, label %for.inc, label %exit.loopexit1

for.inc:
  br label %for.header

exit.loopexit:
  br label %exit

exit.loopexit1:
  br label %exit

exit:
  ret void
}

dtcxzyw · 2025-05-09T14:44:07Z

I will post a patch later.

dtcxzyw · 2025-05-10T08:12:03Z

4d60c6d is correct. This is an iterator-invalidation bug in MemorySSA.

…es` (#139370) This patch defers resetting optimized accesses until all uses are replaced, to avoid invalidating the iterator. Closes #139103. Closes #139289. Closes #139308.

…InsertUpdates` (#139370) This patch defers resetting optimized accesses until all uses are replaced, to avoid invalidating the iterator. Closes llvm/llvm-project#139103. Closes llvm/llvm-project#139289. Closes llvm/llvm-project#139308.

dtcxzyw self-assigned this May 8, 2025

dtcxzyw added llvm:optimizations crash-on-valid needs-reduction Large reproducer that should be reduced into a simpler form generated by fuzzer labels May 8, 2025

dtcxzyw changed the title ~~[MemorySSA] Assertion `!Paths.empty() && "Need a path to move"' failed.~~ [MemorySSA][LoopRotate] Assertion `!Paths.empty() && "Need a path to move"' failed. May 9, 2025

dtcxzyw removed the needs-reduction Large reproducer that should be reduced into a simpler form label May 9, 2025

This was referenced May 9, 2025

A/F: `MA->use_empty() && "Trying to remove memory access that still has uses"' after 4d60c6d #139289

Closed

clang crashes on valid code at -O3 on x86_64-linux-gnu: Segmentation fault #139308

Closed

dtcxzyw mentioned this issue May 10, 2025

[MemorySSAUpdater] Fix iterator invalidation bug in applyInsertUpdates #139370

Merged

EugeneZelenko added llvm:analysis and removed llvm:optimizations labels May 10, 2025

dtcxzyw closed this as completed in #139370 May 10, 2025

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[MemorySSA][LoopRotate] Assertion `!Paths.empty() && "Need a path to move"' failed. #139103

[MemorySSA][LoopRotate] Assertion `!Paths.empty() && "Need a path to move"' failed. #139103

dtcxzyw commented May 8, 2025

dtcxzyw commented May 8, 2025

dtcxzyw commented May 9, 2025

dtcxzyw commented May 9, 2025

dtcxzyw commented May 9, 2025

dtcxzyw commented May 10, 2025

[MemorySSA][LoopRotate] Assertion `!Paths.empty() && "Need a path to move"' failed. #139103

[MemorySSA][LoopRotate] Assertion `!Paths.empty() && "Need a path to move"' failed. #139103

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dtcxzyw commented May 8, 2025

dtcxzyw commented May 8, 2025

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dtcxzyw commented May 10, 2025