Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

[LoopVectorize][VPlan] Assertion "Trying to access a single scalar per part but has multiple scalars per part." failed. #87410

Closed
patrick-rivos opened this issue Apr 2, 2024 · 0 comments · Fixed by #87770
Closed

[LoopVectorize][VPlan] Assertion "Trying to access a single scalar per part but has multiple scalars per part." failed. #87410

patrick-rivos opened this issue Apr 2, 2024 · 0 comments · Fixed by #87770
Labels
crash Prefer [crash-on-valid] or [crash-on-invalid] vectorization

Comments

@patrick-rivos
Copy link
Contributor

Reduced LLVM IR

target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
target triple = "riscv64-unknown-linux-gnu"

define i32 @main() #0 {
entry:
  br label %for.body.i

for.body.i:                                       ; preds = %if.end.i, %entry
  %q.0139.i = phi i16 [ 0, %entry ], [ %add.i, %if.end.i ]
  %idxprom.i = sext i16 0 to i64
  br i1 false, label %if.end.i, label %if.then.i

if.then.i:                                        ; preds = %for.body.i
  br i1 false, label %cond.end41.i, label %cond.end41.i

cond.end41.i:                                     ; preds = %if.then.i, %if.then.i
  br label %if.end.i

if.end.i:                                         ; preds = %cond.end41.i, %for.body.i
  %.in.i = phi ptr [ null, %cond.end41.i ], [ poison, %for.body.i ]
  %0 = load i16, ptr %.in.i, align 2
  %add.i = add i16 %q.0139.i, 1
  %tobool.not.i = icmp eq i16 %add.i, 0
  br i1 %tobool.not.i, label %m.exit, label %for.body.i

m.exit:                                           ; preds = %if.end.i
  %.lcssa = phi i16 [ %0, %if.end.i ]
  ret i32 0
}

attributes #0 = { "target-features"="+64bit,+v" }

Backtrace:

opt: /scratch/tc-testing/tc-apr-2/llvm/llvm/lib/Transforms/Vectorize/VPlan.cpp:249: llvm::Value* llvm::VPTransformState::get(llvm::VPValue*, unsigned int, bool): Assertion `(VF.isScalar() || Def->isLiveIn() || (hasScalarValue(Def, VPIteration(Part, 0)) && Data.PerPartScalars[Def][Part].size() == 1)) && "Trying to access a single scalar per part but has multiple scalars " "per part."' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: /scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt --passes=loop-vectorize reduced.ll
 #0 0x00005ed60f56eb60 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x2d84b60)
 #1 0x00005ed60f56bf6f llvm::sys::RunSignalHandlers() (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x2d81f6f)
 #2 0x00005ed60f56c0c5 SignalHandler(int) Signals.cpp:0:0
 #3 0x00007f973de42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x00007f973de969fc __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 #5 0x00007f973de969fc __pthread_kill_internal ./nptl/pthread_kill.c:78:10
 #6 0x00007f973de969fc pthread_kill ./nptl/pthread_kill.c:89:10
 #7 0x00007f973de42476 gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #8 0x00007f973de287f3 abort ./stdlib/abort.c:81:7
 #9 0x00007f973de2871b _nl_load_domain ./intl/loadmsgcat.c:1177:9
#10 0x00007f973de39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
#11 0x00005ed60e6cbb72 llvm::VPTransformState::get(llvm::VPValue*, unsigned int, bool) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1ee1b72)
#12 0x00005ed60e6fa9a6 llvm::VPInstruction::generatePerPart(llvm::VPTransformState&, unsigned int) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1f109a6)
#13 0x00005ed60e6fbbdf llvm::VPInstruction::execute(llvm::VPTransformState&) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1f11bdf)
#14 0x00005ed60e6d74ff llvm::VPBasicBlock::execute(llvm::VPTransformState*) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1eed4ff)
#15 0x00005ed60e6cd9e0 llvm::VPRegionBlock::execute(llvm::VPTransformState*) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1ee39e0)
#16 0x00005ed60e6d90e6 llvm::VPlan::execute(llvm::VPTransformState*) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1eef0e6)
#17 0x00005ed60e5d76f3 llvm::LoopVectorizationPlanner::executePlan(llvm::ElementCount, unsigned int, llvm::VPlan&, llvm::InnerLoopVectorizer&, llvm::DominatorTree*, bool, llvm::DenseMap<llvm::SCEV const*, llvm::Value*, llvm::DenseMapInfo<llvm::SCEV const*, void>, llvm::detail::DenseMapPair<llvm::SCEV const*, llvm::Value*>> const*) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1ded6f3)
#18 0x00005ed60e5e9718 llvm::LoopVectorizePass::processLoop(llvm::Loop*) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1dff718)
#19 0x00005ed60e5eb73e llvm::LoopVectorizePass::runImpl(llvm::Function&, llvm::ScalarEvolution&, llvm::LoopInfo&, llvm::TargetTransformInfo&, llvm::DominatorTree&, llvm::BlockFrequencyInfo*, llvm::TargetLibraryInfo*, llvm::DemandedBits&, llvm::AssumptionCache&, llvm::LoopAccessInfoManager&, llvm::OptimizationRemarkEmitter&, llvm::ProfileSummaryInfo*) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1e0173e)
#20 0x00005ed60e5ec88d llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x1e0288d)
#21 0x00005ed60d4f3276 llvm::detail::PassModel<llvm::Function, llvm::LoopVectorizePass, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0xd09276)
#22 0x00005ed60f395141 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x2bab141)
#23 0x00005ed60d4eabd6 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0xd00bd6)
#24 0x00005ed60f393e3b llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x2ba9e3b)
#25 0x00005ed60d4f2dc6 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0xd08dc6)
#26 0x00005ed60f391cb1 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x2ba7cb1)
#27 0x00005ed60cd6cce5 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) (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x582ce5)
#28 0x00005ed60cd5f316 optMain (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x575316)
#29 0x00007f973de29d90 __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:58:16
#30 0x00007f973de29e40 call_init ./csu/../csu/libc-start.c:128:20
#31 0x00007f973de29e40 __libc_start_main ./csu/../csu/libc-start.c:379:5
#32 0x00005ed60cd54f95 _start (/scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt+0x56af95)
zsh: IOT instruction (core dumped)  /scratch/tc-testing/tc-apr-2/build-rv64gcv/build-llvm-linux/bin/opt

Godbolt: https://godbolt.org/z/jYWea8z4q

Found via fuzzer.
@EugeneZelenko EugeneZelenko added vectorization crash Prefer [crash-on-valid] or [crash-on-invalid] and removed new issue labels Apr 2, 2024
fhahn added a commit to fhahn/llvm-project that referenced this issue Apr 5, 2024
@fhahn
[VPlan] Remove unused first mask op from VPBlendRecipe.
8ef8f73 
VPBlendRecipe does not use the first mask operand. Removing it allows
VPlan-based DCE to remove unused mask computations.

This also fixes llvm#87410, where unused Not VPInstructions are considered
having only their first lane demanded, but some of their operands
providing a vector value due to other users.

Fixes llvm#87410
@fhahn fhahn mentioned this issue Apr 5, 2024
Merged
fhahn added a commit that referenced this issue Apr 9, 2024
@fhahn
[VPlan] Remove unused first mask op from VPBlendRecipe. (#87770)
c836983 
VPBlendRecipe does not use the first mask operand. Removing it allows
VPlan-based DCE to remove unused mask computations.

This also fixes #87410, where unused Not VPInstructions are considered
having only their first lane demanded, but some of their operands
providing a vector value due to other users.

Fixes #87410

PR: #87770
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
crash Prefer [crash-on-valid] or [crash-on-invalid] vectorization
Projects
None yet
Milestone
No milestone
Development

Successfully merging a pull request may close this issue.

[VPlan] Remove unused first mask op from VPBlendRecipe. fhahn/llvm-project
2 participants
@EugeneZelenko @patrick-rivos