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Re: birthpoints in rtl.


On 3/1/08 5:13 AM, Jan Hubicka wrote:

while I am with Diego that would preffer PHI nodes on side especially in
FUD chain where rest of your SSA is on side too.  But if we go with the
extra instruction scheme, I think you are much better to use RTL USE
instruction.  The moves are generated by target machinery and can do
funny things, like clobbering flags or whatever.  USEs are transparent
this way.

One step at a time, though. Changing the current dense UD chains in DF should be fairly easy. However, going to a rewriting SSA form in RTL is going to be more involved. We may even need to do the same split we do in GIMPLE and have both a rewriting form and a FUD-chain form.



Diego.



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