[LLVMdev] Reusing CFG structures

[Slobodan Pejic]

Ball Larus path profiling requires temporarily changing the CFG by 
replacing backedges (such as those caused by loops) in order to 
determine instrumentation placement, and attaching increments to edges 
[Ball96].  As far as I understand the CFG available through the 
BasicBlock class directly corresponds to the IR.  I would rather not 
change the IR except to insert the profiling code.  So, is there a graph 
structure that can be reused for such a purpose? Am I approaching this 
the wrong way?

Thanks

[Ball96]
T. Ball and J. R. Larus. "Efficient Path Profiling."
International Symposium on Microarchitecture, pages 46-57, 1996.
http://portal.acm.org/citation.cfm?id=243857