birthpoints in rtl.

[Diego Novillo]

On 2/29/08 7:04 PM, Steven Bosscher wrote:

> I am not sure what would happen if GCC would start using FUD chains.
> Is it like in SSA that every register is assigned only once?

But this would only affect the UD chains built by the DF code.  My idea 
is to build the same UD chains, but make them sparse instead of the 
dense web we have today.  None of this would be in the IL stream, only 
on the DF web.

Representing PHI nodes as a NOP could be an option for getting an 
initial implementation quickly.


Diego.