| Issue |
120615
|
| Summary |
[SCEV] Segfault in SCEV LoopGuards
|
| Labels |
llvm:crash,
llvm:SCEV,
crash-on-valid
|
| Assignees |
|
| Reporter |
danilaml
|
For the following IR:
```llvm
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-ni:1-p2:32:8:8:32-ni:2"
target triple = "x86_64-unknown-linux-gnu"
define void @foo() {
.split.us120:
br label %.split.us120.split.split.us.split.split.us.split.split.us.split
.split.us120.split.split.us.split.split.us.split.split.us.split: ; preds = %.noexc7.us.us.us.us.us, %.split.us120
br label %.noexc7.us.us.us.us.us
.lr.ph.us.us.us.us407: ; No predecessors!
switch i32 0, label %.split142.us.split.us.split.us [
i32 0, label %.split160.us.split.us.split.us
i32 1, label %.noexc7.us.us.us.us.us
]
.noexc7.us.us.us.us.us: ; preds = %.noexc7.us.us.us.us.us, %.lr.ph.us.us.us.us407, %.split.us120.split.split.us.split.split.us.split.split.us.split
%0 = phi i32 [ %1, %.noexc7.us.us.us.us.us ], [ 0, %.lr.ph.us.us.us.us407 ], [ 0, %.split.us120.split.split.us.split.split.us.split.split.us.split ]
%1 = add i32 %0, 1
%.not.i3.us.us.us.us384.us = icmp slt i32 %0, 0
br i1 %.not.i3.us.us.us.us384.us, label %.noexc7.us.us.us.us.us, label %.split.us120.split.split.us.split.split.us.split.split.us.split
.split142.us.split.us.split.us: ; preds = %.lr.ph.us.us.us.us407
ret void
.split160.us.split.us.split.us: ; preds = %.lr.ph.us.us.us.us407
ret void
}
```
`opt` crashes when run using `-passes=nary-reassociate --scalar-evolution-use-expensive-range-sharpening`
godbolt: https://godbolt.org/z/xPv4TMMo8
Backtrace (truncated due to length limits):
````
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0. Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/opt -o /app/output.s -S -passes=nary-reassociate --scalar-evolution-use-expensive-range-sharpening <source>
1. Running pass "function(nary-reassociate)" on module "<source>"
2. Running pass "nary-reassociate" on function "foo"
#0 0x0000000005257198 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5257198)
#1 0x0000000005254b9c SignalHandler(int) Signals.cpp:0:0
#2 0x00007f9ab9c42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
#3 0x00000000051640cb llvm::hash_value(llvm::APInt const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x51640cb)
#4 0x00000000051641a9 llvm::DenseMapInfo<llvm::APInt, void>::getHashValue(llvm::APInt const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x51641a9)
#5 0x0000000004ed726b bool llvm::DenseMapBase<llvm::DenseMap<llvm::APInt, std::unique_ptr<llvm::ConstantInt, std::default_delete<llvm::ConstantInt>>, llvm::DenseMapInfo<llvm::APInt, void>, llvm::detail::DenseMapPair<llvm::APInt, std::unique_ptr<llvm::ConstantInt, std::default_delete<llvm::ConstantInt>>>>, llvm::APInt, std::unique_ptr<llvm::ConstantInt, std::default_delete<llvm::ConstantInt>>, llvm::DenseMapInfo<llvm::APInt, void>, llvm::detail::DenseMapPair<llvm::APInt, std::unique_ptr<llvm::ConstantInt, std::default_delete<llvm::ConstantInt>>>>::LookupBucketFor<llvm::APInt>(llvm::APInt const&, llvm::detail::DenseMapPair<llvm::APInt, std::unique_ptr<llvm::ConstantInt, std::default_delete<llvm::ConstantInt>>>*&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4ed726b)
#6 0x0000000004edb996 llvm::ConstantInt::get(llvm::LLVMContext&, llvm::APInt const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4edb996)
#7 0x0000000004eeba30 llvm::ConstantInt::get(llvm::Type*, llvm::APInt const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4eeba30)
#8 0x0000000004eb6172 llvm::ConstantFoldBinaryInstruction(unsigned int, llvm::Constant*, llvm::Constant*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4eb6172)
#9 0x0000000004ee9f2e llvm::ConstantExpr::get(unsigned int, llvm::Constant*, llvm::Constant*, unsigned int, llvm::Type*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4ee9f2e)
#10 0x00000000049427fb llvm::ScalarEvolution::getNegativeSCEV(llvm::SCEV const*, llvm::SCEV::NoWrapFlags) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x49427fb)
#11 0x00000000049429c4 llvm::ScalarEvolution::getMinusSCEV(llvm::SCEV const*, llvm::SCEV const*, llvm::SCEV::NoWrapFlags, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x49429c4)
#12 0x0000000004950e7a llvm::ScalarEvolution::LoopGuards::collectFromBlock(llvm::ScalarEvolution&, llvm::ScalarEvolution::LoopGuards&, llvm::BasicBlock const*, llvm::BasicBlock const*, llvm::SmallPtrSetImpl<llvm::BasicBlock const*>&, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4950e7a)
#13 0x00000000049524c2 llvm::ScalarEvolution::LoopGuards::collectFromPHI(llvm::ScalarEvolution&, llvm::ScalarEvolution::LoopGuards&, llvm::PHINode const&, llvm::SmallPtrSetImpl<llvm::BasicBlock const*>&, llvm::SmallDenseMap<llvm::BasicBlock const*, llvm::ScalarEvolution::LoopGuards, 4u, llvm::DenseMapInfo<llvm::BasicBlock const*, void>, llvm::detail::DenseMapPair<llvm::BasicBlock const*, llvm::ScalarEvolution::LoopGuards>>&, unsigned int)::'lambda'(unsigned int)::operator()(unsigned int) const ScalarEvolution.cpp:0:0
#14 0x0000000004952702 llvm::ScalarEvolution::LoopGuards::collectFromPHI(llvm::ScalarEvolution&, llvm::ScalarEvolution::LoopGuards&, llvm::PHINode const&, llvm::SmallPtrSetImpl<llvm::BasicBlock const*>&, llvm::SmallDenseMap<llvm::BasicBlock const*, llvm::ScalarEvolution::LoopGuards, 4u, llvm::DenseMapInfo<llvm::BasicBlock const*, void>, llvm::detail::DenseMapPair<llvm::BasicBlock const*, llvm::ScalarEvolution::LoopGuards>>&, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4952702)
#15 0x0000000004951839 llvm::ScalarEvolution::LoopGuards::collectFromBlock(llvm::ScalarEvolution&, llvm::ScalarEvolution::LoopGuards&, llvm::BasicBlock const*, llvm::BasicBlock const*, llvm::SmallPtrSetImpl<llvm::BasicBlock const*>&, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4951839)
#16 0x0000000004952c7d llvm::ScalarEvolution::applyLoopGuards(llvm::SCEV const*, llvm::Loop const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4952c7d)
#17 0x0000000004952fb0 llvm::ScalarEvolution::getRangeForAffineNoSelfWrappingAR(llvm::SCEVAddRecExpr const*, llvm::SCEV const*, unsigned int, llvm::ScalarEvolution::RangeSignHint) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4952fb0)
#18 0x000000000492888d llvm::ScalarEvolution::getRangeRef(llvm::SCEV const*, llvm::ScalarEvolution::RangeSignHint, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x492888d)
#19 0x0000000004942b52 llvm::ScalarEvolution::isKnownPredicateViaConstantRanges(llvm::CmpInst::Predicate, llvm::SCEV const*, llvm::SCEV const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4942b52)
#20 0x0000000004942e18 llvm::ScalarEvolution::isKnownViaNonRecursiveReasoning(llvm::CmpInst::Predicate, llvm::SCEV const*, llvm::SCEV const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4942e18)
#21 0x0000000004943799 llvm::ScalarEvolution::getMinMaxExpr(llvm::SCEVTypes, llvm::SmallVectorImpl<llvm::SCEV const*>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4943799)
#22 0x0000000004943f1a llvm::ScalarEvolution::getSMinExpr(llvm::SCEV const*, llvm::SCEV const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4943f1a)
#23 0x0000000004951128 llvm::ScalarEvolution::LoopGuards::collectFromBlock(llvm::ScalarEvolution&, llvm::ScalarEvolution::LoopGuards&, llvm::BasicBlock const*, llvm::BasicBlock const*, llvm::SmallPtrSetImpl<llvm::BasicBlock const*>&, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4951128)
...
#255 0x00000000049524c2 llvm::ScalarEvolution::LoopGuards::collectFromPHI(llvm::ScalarEvolution&, llvm::ScalarEvolution::LoopGuards&, llvm::PHINode const&, llvm::SmallPtrSetImpl<llvm::BasicBlock const*>&, llvm::SmallDenseMap<llvm::BasicBlock const*, llvm::ScalarEvolution::LoopGuards, 4u, llvm::DenseMapInfo<llvm::BasicBlock const*, void>, llvm::detail::DenseMapPair<llvm::BasicBlock const*, llvm::ScalarEvolution::LoopGuards>>&, unsigned int)::'lambda'(unsigned int)::operator()(unsigned int) const ScalarEvolution.cpp:0:0
Program terminated with signal: SIGSEGV
Compiler returned: 139
```
Stack exhaustion via some recursion error maybe?
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