[LLVMdev] Code instruction selection based on SSA-graphs

[Evan Cheng]

>
> What do you think about this approach? Whould it be interesting to
> implement something like that for LLVM? May be you already have
> considered something like that? Are there any plans to it?

We have talked about whole function instruction selection but does  
not have immediate plan to implement it. If we were to implement it  
today, it would probably be done on DAGs with control flow between  
blocks being modeled as chain operands.

Implementing what is described in the paper would require boolean  
query system like PBQP. That's no trivial matter. We definitely  
welcome contribution in this area. :-) In additional to being  
required for the instruction selection algorithm described, it is  
also very useful for backends with predicated execution (e.g. IA64).

Evan