ddg in the gcc compiler

[Wei Li <weili747 at gmail dot com>]

Dear all:

Just follow up to my previous request on printing ddgs using the gcc.
I am thankful to the people who gave comments. I still feel that I
need some more from the GCC experts.

I want ddgs for each basic blocks for each function at the RTL level.
I looked inside the gcc code and found following functions which could
be useful in this regard.

1- print_rtl_with_bb() in cfgrtl.c
2- create_ddg() in ddg.c
3- vcg_print_ddg() in ddg.c


Now my questions are:

1- Is the function "print_rtl_with_bb" right place to create a DDG for
each basic block? If I call the function "create_ddg" at this level,
will it be able to give me latency between instructions and type of
each instruction?

2- create_ddg has two arguments a) basic_block bb and b) int
closing_branch_deps. What is the argument-b and how can I determine
its value?

Thanks in advance for your time and comments.
-- 
Regards,

Wei Li