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我试图找到存储指令的指针操作数和函数参数之间的别名。这是代码,LLVM中的别名分析
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;
}
};
}
但是,即使存储指令的指针操作数没有引用函数参数,我也会得到MayAlias的结果。逻辑有问题吗? LLVM源代码中是否有包含代码的任何文件来执行类似操作。谢谢:)