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This proposal adds support for path profiling [Ball96] to LLVM. Path profiling compactly represents acyclic paths in a directed acyclic graph representation of the control flow graph of a routine. Instrumentation can be added to uniquely identify paths executed at runtime. Path profiles enable precise enumeration of the sequence of basic blocks execut...

Hi Vedant, I would like to clarify that the proposal does *intra-procedural* path profiling as described in [Ball96]. > > This proposal adds support for path profiling [Ball96] to LLVM. Path profiling compactly represents acyclic paths in a directed acyclic graph representation of the control flow graph of a routine. Instrumentation can be added to uniquely identify paths executed at runtime. > In [...

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 [B...