https://llvm.org/bugs/show_bug.cgi?id=30486
Bug ID: 30486 Summary: [InstCombine] Crash in InstructionCombining.cpp due to a cast failure in switch control condition Product: new-bugs Version: 3.9 Hardware: PC OS: Linux Status: NEW Severity: normal Priority: P Component: new bugs Assignee: unassignedb...@nondot.org Reporter: s3r...@gmail.com CC: llvm-bugs@lists.llvm.org Classification: Unclassified InstCombine in LLVM 3.9 (and also in the current trunk, I checked this on rev. 282138) crashes in InstructionCombining.cpp due to a cast failure in switch control condition. Input: ------ @g = global i32 0 define i32 @func() { switch i32 add (i32 ptrtoint (i32* @g to i32), i32 -1), label %x [] x: ret i32 0 } Run: ---- $ opt -instcombine input.ll -o output.bc Output: ------- 0 libLLVM-3.9.so.1 0x00007fe0baa0e255 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 37 1 libLLVM-3.9.so.1 0x00007fe0baa0c45e llvm::sys::RunSignalHandlers() + 62 2 libLLVM-3.9.so.1 0x00007fe0baa0c59a 3 libpthread.so.0 0x00007fe0bce108d0 4 libLLVM-3.9.so.1 0x00007fe0baa9ab9b llvm::Instruction::eraseFromParent() + 27 5 libLLVM-3.9.so.1 0x00007fe0bb0900bb 6 libLLVM-3.9.so.1 0x00007fe0bb098c36 7 libLLVM-3.9.so.1 0x00007fe0bb09a5f9 8 libLLVM-3.9.so.1 0x00007fe0bb09a87c llvm::InstructionCombiningPass::runOnFunction(llvm::Function&) + 476 9 libLLVM-3.9.so.1 0x00007fe0baabe312 llvm::FPPassManager::runOnFunction(llvm::Function&) + 482 10 libLLVM-3.9.so.1 0x00007fe0baabe64b llvm::FPPassManager::runOnModule(llvm::Module&) + 43 11 libLLVM-3.9.so.1 0x00007fe0baabe930 llvm::legacy::PassManagerImpl::run(llvm::Module&) + 704 12 opt 0x000000000044d43a main + 7130 13 libc.so.6 0x00007fe0b99e8b45 __libc_start_main + 245 14 opt 0x0000000000457015 Stack dump: 0. Program arguments: opt -instcombine input.ll -o output.bc 1. Running pass 'Function Pass Manager' on module 'input.ll'. 2. Running pass 'Combine redundant instructions' on function '@func' Segmentation fault Expected output: ---------------- opt does not crash. Cause: ------ There is the following code in lib/Transforms/InstCombine/InstructionCombining.cpp (LLVM trunk, rev. 282138): 2274 ConstantInt *AddRHS = nullptr; 2275 if (match(Cond, m_Add(m_Value(), m_ConstantInt(AddRHS)))) { 2276 Instruction *I = cast<Instruction>(Cond); The cast<> on line 2276 fails when the condition (`Cond` variable) is as in the input file. There needs to be a dyn_cast<> instead because the cast may fail (as can be seen from this bug report). Environment: ------------ - Official pre-build version of LLVM 3.9 for Debian Jessie (but the bug is reproducible also in the current trunk, I checked that on rev. 282138). - Fully updated Debian Jessie x86_64, GCC 4.9.2. -- You are receiving this mail because: You are on the CC list for the bug.
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