[LLVMdev] Infinite loop when adding a new analysis pass

[Junjie Gu]

I am trying to add an analysis pass as a FunctionPass,  and let LICM
(LoopPass) depends upon it.  So in LICM.cpp, I have the following:

    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
      AU.setPreservesCFG();
      AU.addRequired<DominatorTree>();
      AU.addRequired<LoopInfo>();
      AU.addRequiredID(LoopSimplifyID);
      AU.addRequired<AliasAnalysis>();
      AU.addRequired<MyAnalysis>();                         //  Add this
      AU.addPreserved<AliasAnalysis>();
      AU.addPreserved("scalar-evolution");
      AU.addPreservedID(LoopSimplifyID);
    }


char LICM::ID = 0;
INITIALIZE_PASS_BEGIN(LICM, "licm", "Loop Invariant Code Motion", false, false)
INITIALIZE_PASS_DEPENDENCY(DominatorTree)
INITIALIZE_PASS_DEPENDENCY(LoopInfo)
INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
INITIALIZE_PASS_DEPENDENCY(MyAnalysis)
             // add this dependency
INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
INITIALIZE_PASS_END(LICM, "licm", "Loop Invariant Code Motion", false, false)


Howerver,  I got an infinite loop when trying

opt -O3 t.bc -o out.bc

Where t.bc is created using clang from
  int main() { return 0; }

What am I missing ?

All files are attacahed (include/Analysis/MyAnalysis.h,
lib/Analysis/MyAnanlysis.cpp,  and diffs to the existing files).

Thanks
Junjie
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