llc: ../lib/Transforms/Scalar/LoopStrengthReduce.cpp:6630: [...] Assertion `!LocationOps.empty() && "Expected the location ops to contain the IV."' failed.

[mikaelholmen]

llvm commit: 82e594a
Reproduce with: llc bbi-99605.ll -o /dev/null
Result:

llc: ../lib/Transforms/Scalar/LoopStrengthReduce.cpp:6630: void (anonymous namespace)::SCEVDbgValueBuilder::appendToVectors(SmallVectorImpl<uint64_t> &, SmallVectorImpl<llvm::Value *> &): Assertion `!LocationOps.empty() && "Expected the location ops to contain the IV."' 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/llc bbi-99605.ll -o /dev/null
1.	Running pass 'Function Pass Manager' on module 'bbi-99605.ll'.
2.	Running pass 'Loop Pass Manager' on function '@main'
3.	Running pass 'Loop Strength Reduction' on basic block '%for.cond29'
 #0 0x000055e150599557 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (build-all/bin/llc+0x6dee557)
 #1 0x000055e1505970be llvm::sys::RunSignalHandlers() (build-all/bin/llc+0x6dec0be)
 #2 0x000055e150599bff SignalHandler(int) Signals.cpp:0:0
 #3 0x00007f66b410bcf0 __restore_rt (/lib64/libpthread.so.0+0x12cf0)
 #4 0x00007f66b1cc4acf raise (/lib64/libc.so.6+0x4eacf)
 #5 0x00007f66b1c97ea5 abort (/lib64/libc.so.6+0x21ea5)
 #6 0x00007f66b1c97d79 _nl_load_domain.cold.0 (/lib64/libc.so.6+0x21d79)
 #7 0x00007f66b1cbd426 (/lib64/libc.so.6+0x47426)
 #8 0x000055e15005db21 (build-all/bin/llc+0x68b2b21)
 #9 0x000055e15005c0c3 SalvageDVI(llvm::Loop*, llvm::ScalarEvolution&, llvm::PHINode*, (anonymous namespace)::DVIRecoveryRec&, llvm::SCEV const*, (anonymous namespace)::SCEVDbgValueBuilder) LoopStrengthReduce.cpp:0:0
#10 0x000055e15002dca8 ReduceLoopStrength(llvm::Loop*, llvm::IVUsers&, llvm::ScalarEvolution&, llvm::DominatorTree&, llvm::LoopInfo&, llvm::TargetTransformInfo const&, llvm::AssumptionCache&, llvm::TargetLibraryInfo&, llvm::MemorySSA*) LoopStrengthReduce.cpp:0:0
#11 0x000055e15005e7e8 (anonymous namespace)::LoopStrengthReduce::runOnLoop(llvm::Loop*, llvm::LPPassManager&) LoopStrengthReduce.cpp:0:0
#12 0x000055e14f26f0f9 llvm::LPPassManager::runOnFunction(llvm::Function&) (build-all/bin/llc+0x5ac40f9)
#13 0x000055e14fba9e38 llvm::FPPassManager::runOnFunction(llvm::Function&) (build-all/bin/llc+0x63fee38)
#14 0x000055e14fbb2171 llvm::FPPassManager::runOnModule(llvm::Module&) (build-all/bin/llc+0x6407171)
#15 0x000055e14fbaa8b5 llvm::legacy::PassManagerImpl::run(llvm::Module&) (build-all/bin/llc+0x63ff8b5)
#16 0x000055e14d988be8 compileModule(char**, llvm::LLVMContext&) llc.cpp:0:0
#17 0x000055e14d98626d main (build-all/bin/llc+0x41db26d)
#18 0x00007f66b1cb0d85 __libc_start_main (/lib64/libc.so.6+0x3ad85)
#19 0x000055e14d9822ee _start (build-all/bin/llc+0x41d72ee)
Abort (core dumped)

The input contains the new debug info:
#dbg_value(i128 %l_995.0, !4, !DIExpression(), !9)

bbi-99605.ll.gz