[LLVMdev] Making Sense of ISel DAG Output

David Greene dag at cray.com
Fri Oct 3 09:12:23 PDT 2008

On Thursday 02 October 2008 19:22, Dan Gohman wrote:

> Another trick is to place an abort() call somewhere in codegen
> such that it will be called whenever the construct of interest
> is processed, and then run bugpoint. If it works, the result
> is a reduced testcase that's still interesting :-).

That's a neat trick.  I'll see if I can do that.

> 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 


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