birthpoints in rtl.

[Diego Novillo]

On 2/28/08 8:59 AM, Jan Hubicka wrote:

> Yes, I do believe that wast majority of DU/UD code can stay as it is.
> We just need to introduce the PHI nodes, either in a way Gimple does
> that in separate section of CFG or as real RTL noop moves (or we can
> even have RTL PHI code that would behave same way as USEs does
> not, ie bypass machine validation issues).

Introducing them as objects in the DF datastructures may be more 
convenient.  You just make them a separate list of PHI nodes in each BB 
as we have in GIMPLE.



Diego.