printing ddg for each basic block

[Wei Li]

Hi all:

I need to print ddg for each basic block in CFG. I used  option -dv.
However, it gives a DAG for CFG where each node is a basic block. I
see a function "vcg_print_ddg(FILE* file, ddg_ptr)" in the ddg.c file.
It means that you can have a ddg for each basic block in the CVG
format. How can I activate this using gcc options like -dv etc.?

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Regards,

Wei Li