[LLVMdev] [PATCH] Add functionality to scc_iterator

[John T. Criswell]

Patrick Simmons wrote:
> Chris Lattner wrote:
>   
>> On Aug 7, 2009, at 12:51 PM, Vikram S. Adve wrote:
>>
>>   
>>     
>>> Checking if a graph node is in a cycle or not must be a relatively
>>> common query.  E.g., we used this on DS graphs to decide if DS node
>>> represented multiple objects or a single object.  It's the basic query
>>> to decide if a function is part of a recursive computation (a cycle in
>>> the call graph).  CFGs happen to have special code for natural loops
>>> but you could use this query to handle irreducible loops as well.
>>>     
>>>       
>> These typically don't use the scciterator though.
>>
>> -Chris
>>
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>>   
>>     
> Is there a better method for checking whether a basic block is part of a 
> cycle I should be using?
>   
SAFECode has a pass called BottomUpCallGraph which provides methods for 
determining if a function is called recursively.

Patrick, if you need functionality like this, you might want to look at 
this pass in the SAFECode source code.

To other DSA users: would it make sense to move this pass into DSA?  It 
doesn't seem to be a SAFECode specific piece of code.

-- John T.

> --Patrick
>
>