llvm dev - Oct 2012 - [LLVMdev] Use information generated by existing passes into new pass

Hi,
I want to ask is that can we use the information generated by existing
passes into a new pass? If yes, then how ?
For example -loops gives the natural loop information, so can we use this
information into new pass by calling it.

-- 
Sunil Rathee
MTech
IIT Delhi

Not going along with the crowd can help you stand out in the crowd
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Hi Sunil,
> I want to ask is that can we use the information generated by existing
passes
> into a new pass? If yes, then how ?
> For example -loops gives the natural loop information, so can we use this
> information into new pass by calling it.
in your pass's getAnalysisUsage method you use addRequired to specify that
you
need a particular analysis, for example

     void MyPass::getAnalysisUsage(AnalysisUsage &AU) const {
...
       AU.addRequired<LoopInfo>();
...
     }

Then, to get hold of the analysis when your pass is being run, you can use
getAnalysis<LoopInfo>() .

Ciao, Duncan.