[PATCH] D40390: [InstCombine] Don't crash on out of bounds index in the insertelement

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

I may be confused by the incremental diffs in these reviews, but we can minimize the insertelement test to just one line and still crash trunk:

> $ cat inselt.ll
> 
> define <4 x double> @inselt_bad_index(<4 x double> %a) {
>  %I = insertelement <4 x double> %a, double 0.0, i64 4294967296
>  ret <4 x double> %I
>  }
> 
> $ ./opt -instcombine inselt.ll -S
>  Assertion failed: (idx < size()), function operator[], file /Users/spatel/myllvm/llvm/include/llvm/ADT/SmallVector.h, line 149.
>  0  opt                      0x0000000112a576bc llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 60
>  1  opt                      0x0000000112a57cb9 PrintStackTraceSignalHandler(void*) + 25
>  2  opt                      0x0000000112a53749 llvm::sys::RunSignalHandlers() + 425
>  3  opt                      0x0000000112a58072 SignalHandler(int) + 354
>  4  libsystem_platform.dylib 0x00007fff5d2eaf5a _sigtramp + 26
>  5  libsystem_platform.dylib 000000000000000000 _sigtramp + 2731626688
>  6  libsystem_c.dylib        0x00007fff5d11630a abort + 127
>  7  libsystem_c.dylib        0x00007fff5d0de360 basename_r + 0
>  8  opt                      0x00000001122abdeb foldInsSequenceIntoBroadcast(llvm::InsertElementInst&) + 603
>  9  opt                      0x00000001122a94e0 llvm::InstCombiner::visitInsertElementInst(llvm::InsertElementInst&) + 1664
>  10 opt                      0x00000001121e82a8 llvm::InstVisitor<llvm::InstCombiner, llvm::Instruction*>::visitInsertElement(llvm::InsertElementInst&) + 40
>  11 opt                      0x00000001121d9872 llvm::InstVisitor<llvm::InstCombiner, llvm::Instruction*>::visit(llvm::Instruction&) + 1762
>  12 opt                      0x00000001121d8b19 llvm::InstCombiner::run() + 2569
>  13 opt                      0x00000001121da07f combineInstructionsOverFunction(llvm::Function&, llvm::InstCombineWorklist&, llvm::AAResults*, llvm::AssumptionCache&, llvm::TargetLibraryInfo&, llvm::DominatorTree&, llvm::OptimizationRemarkEmitter&, bool, llvm::LoopInfo*) + 1007
>  14 opt                      0x00000001121da306 llvm::InstructionCombiningPass::runOnFunction(llvm::Function&) + 342
>  15 opt                      0x0000000111e7bf8f llvm::FPPassManager::runOnFunction(llvm::Function&) + 399
>  16 opt                      0x0000000111e7c495 llvm::FPPassManager::runOnModule(llvm::Module&) + 117
>  17 opt                      0x0000000111e7d264 (anonymous namespace)::MPPassManager::runOnModule(llvm::Module&) + 2196
>  18 opt                      0x0000000111e7c756 llvm::legacy::PassManagerImpl::run(llvm::Module&) + 342
>  19 opt                      0x0000000111e7dfb1 llvm::legacy::PassManager::run(llvm::Module&) + 33
>  20 opt                      0x000000010f8f58fc main + 27756
>  21 libdyld.dylib            0x00007fff5d06a145 start + 1
>  Stack dump:
>  0.	Program arguments: ./opt -instcombine inselt.ll -S
> 
> 1. Running pass 'Function Pass Manager' on module 'inselt.ll'.
> 2. Running pass 'Combine redundant instructions' on function '@inselt_bad_index' Abort trap: 6




https://reviews.llvm.org/D40390