[LLVMbugs] [Bug 3909] New: assert in SCEV

[bugzilla-daemon at cs.uiuc.edu]

http://llvm.org/bugs/show_bug.cgi?id=3909

           Summary: assert in SCEV
           Product: new-bugs
           Version: unspecified
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Keywords: compile-fail
          Severity: normal
          Priority: P2
         Component: new bugs
        AssignedTo: unassignedbugs at nondot.org
        ReportedBy: kamm-removethis at incasoftware.de
                CC: llvmbugs at cs.uiuc.edu


Created an attachment (id=2777)
 --> (http://llvm.org/bugs/attachment.cgi?id=2777)
test case, generated by the LLVM D compiler and simplified manually

Assembling the attached code with 'llc bug.bc' triggers the assert

ScalarEvolutionExpressions.h:570: RetVal llvm::SCEVVisitor<SC,
RetVal>::visitCouldNotCompute(llvm::SCEVCouldNotCompute*) [with SC =
llvm::SCEVExpander, RetVal = llvm::Value*]: Assertion `0 && "Invalid use of
SCEVCouldNotCompute!"' failed.

with LLVM 2.5. The issue seems to be i64 related: if you replace all i64s with
i32s, the code is assembled fine. The backtrace is:

4   libc.so.6 0xb7d01f25 __assert_fail + 245
5   llc       0x08d0fc9a
llvm::LoopBase<llvm::BasicBlock>::isLoopInvariant(llvm::Value*) const + 0
6   llc       0x08d10861 llvm::SCEVVisitor<llvm::SCEVExpander,
llvm::Value*>::visit(llvm::SCEV*) + 337
7   llc       0x08d0e3fd llvm::SCEVExpander::expand(llvm::SCEV*) + 161
8   llc       0x08d0f0f2
llvm::SCEVExpander::visitAddRecExpr(llvm::SCEVAddRecExpr*) + 1956
9   llc       0x08d10802 llvm::SCEVVisitor<llvm::SCEVExpander,
llvm::Value*>::visit(llvm::SCEV*) + 242
10  llc       0x08d0e3fd llvm::SCEVExpander::expand(llvm::SCEV*) + 161
11  llc       0x08d0e46d llvm::SCEVExpander::expandCodeFor(llvm::SCEVHandle,
llvm::Instruction*) + 41
12  llc       0x08c854d0
13  llc       0x08c87748
14  llc       0x08ce83af llvm::LPPassManager::runOnFunction(llvm::Function&) +
911
15  llc       0x08d91a0e llvm::FPPassManager::runOnFunction(llvm::Function&) +
258
16  llc       0x08d91f98 llvm::FunctionPassManagerImpl::run(llvm::Function&) +
116
17  llc       0x08d920f1 llvm::FunctionPassManager::run(llvm::Function&) + 137
18  llc       0x08513503 main + 2479


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