[LLVMdev] Making Sense of ISel DAG Output

[Dan Gohman]

On Fri, October 3, 2008 9:12 am, David Greene wrote:
>> A feature that would be really useful for large graphs that LLVM
>> doesn't yet have is the ability to display subsets of the graph.
>> For example, take a node of interest and show just it and its
>> operands and its users. Or maybe two or three or N levels of
>> operands.
>
> Yes, this would be helpful.  I also looked at creating a setSubgraphColor
> method that would color the node and its children.  But there doesn't seem
> to
> be a convenient way to traverse SelectionDAGs.  It seems to be hard-coded
> by
> tblgen.

Take a look at SDNodeIterator and the GraphTraits for SDNode*
in SelectionDAGNodes.h.

Dan