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| author | Dmitri Gribenko <gribozavr@gmail.com> | 2024-05-16 12:05:13 +0200 |
|---|---|---|
| committer | Dmitri Gribenko <gribozavr@gmail.com> | 2024-05-16 12:11:42 +0200 |
| commit | 83974a4b92d1fd33b8e21d7a868862893d9430e9 (patch) | |
| tree | d5130166dafb569f1ecd154c93138236acc2e40d /lldb/packages/Python/lldbsuite/test/lldbgdbclient.py | |
| parent | 5ffd154cf61390c1ed32a1b0eb134929f78c0fbe (diff) | |
| download | llvm-83974a4b92d1fd33b8e21d7a868862893d9430e9.zip llvm-83974a4b92d1fd33b8e21d7a868862893d9430e9.tar.gz llvm-83974a4b92d1fd33b8e21d7a868862893d9430e9.tar.bz2 | |
Revert "[LoopUnroll] Clamp PartialThreshold for large LoopMicroOpBufferSize (#67657)"
This reverts commit f0b3654701bde1cf7821d60698b42383edaff9f3.
This commit triggers UB by reading an uninitialized variable.
`UP.PartialThreshold` is used uninitialized in `getUnrollingPreferences()` when
it is called from `LoopVectorizationPlanner::executePlan()`. In this case the
`UP` variable is created on the stack and its fields are not initialized.
```
==8802==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x557c0b081b99 in llvm::BasicTTIImplBase<llvm::X86TTIImpl>::getUnrollingPreferences(llvm::Loop*, llvm::ScalarEvolution&, llvm::TargetTransformInfo::UnrollingPreferences&, llvm::OptimizationRemarkEmitter*) llvm-project/llvm/include/llvm/CodeGen/BasicTTIImpl.h
#1 0x557c0b07a40c in llvm::TargetTransformInfo::Model<llvm::X86TTIImpl>::getUnrollingPreferences(llvm::Loop*, llvm::ScalarEvolution&, llvm::TargetTransformInfo::UnrollingPreferences&, llvm::OptimizationRemarkEmitter*) llvm-project/llvm/include/llvm/Analysis/TargetTransformInfo.h:2277:17
#2 0x557c0f5d69ee in llvm::TargetTransformInfo::getUnrollingPreferences(llvm::Loop*, llvm::ScalarEvolution&, llvm::TargetTransformInfo::UnrollingPreferences&, llvm::OptimizationRemarkEmitter*) const llvm-project/llvm/lib/Analysis/TargetTransformInfo.cpp:387:19
#3 0x557c0e6b96a0 in 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*) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:7624:7
#4 0x557c0e6e4b63 in llvm::LoopVectorizePass::processLoop(llvm::Loop*) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10253:13
#5 0x557c0e6f2429 in 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*) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10344:30
#6 0x557c0e6f2f97 in llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10383:9
[...]
Uninitialized value was created by an allocation of 'UP' in the stack frame
#0 0x557c0e6b961e in 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*) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:7623:3
```
Diffstat (limited to 'lldb/packages/Python/lldbsuite/test/lldbgdbclient.py')
0 files changed, 0 insertions, 0 deletions