[LLVMdev] Alias analysis result

[Borya Egorov]

Hello everyone,
I am trying to find the alias between a store instruction's pointer operand
and function arguments. This is the code,
virtual void getAnalysisUsage(AnalysisUsage &AU) const {

        AU.addRequiredTransitive<AliasAnalysis>();
        AU.addPreserved<AliasAnalysis>();
    }
virtual bool runOnFunction(Function &F) {


        AliasAnalysis &AA = getAnalysis<AliasAnalysis>();

        for(Function::iterator i=F.begin();i!=F.end();++i){
            for(BasicBlock::iterator j=i->begin();j!=i->end();++j)
            {


                if(dyn_cast<StoreInst>(j)){

                    const StoreInst *SI=dyn_cast<StoreInst>(j);

                         AliasAnalysis::Location LocA = AA.getLocation(SI);


                    const Value *si_v= SI->getPointerOperand();

                    for(Function::arg_iterator k=F.arg_begin();
k!=F.arg_end();++k)
                    {


                         Value *v=dyn_cast<Value>(k);

                        AliasAnalysis::Location
loc=AliasAnalysis::Location(v);
                        AliasAnalysis::AliasResult ar=AA.alias(LocA,loc);

                        switch(ar)
                        {
                        case 0:errs()<<  "NoAlias\n";
                        break;
                        ///< No dependencies.
                        case 1:errs()<<"MayAlias\n";    ///< Anything goes
                        break;
                        case 2: errs()<<"PartialAlias\n";///< Pointers
differ, but pointees overlap.
                        break;

                        case 3: errs()<<"MustAlias\n";
                        }






            }
        }



        return true;
    }
};
}

But I get MayAlias result even if the store instruction's pointer operand
is not referencing  the function argument. Is there something wrong with
the logic? Are there any files in the LLVM source code that contain code to
do something similar.
Thanks:)
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