[tree-ssa]: out-of-ssa breaks if something adds a pred

[Daniel Berlin]

On Friday, June 6, 2003, at 04:18  PM, Chris Lattner wrote:

>>> IMO, this is a failure of the edge insertion routines or the caller 
>>> of
>>> the
>>> routine.
>>
>> Well, the caller can't know what the inserter did, and what to do to
>> the possibly affected phi's.
>
> OTOH, the inserter cannot possibly know how to update the PHI nodes, 
> only
> the caller can.  If the caller doesn't know how to update the PHI 
> nodes,
> something is seriously wrong.

The inserter created the new bb and edges, it thus should know how to 
update the phi nodes.

>
>> Plus, the current way we create phi nodes would mean that we'd have to
>> rebuild all the phi's (their number of arguments is fixed at creation
>> time). Diego, what to do here?
>
> Why?  What are you trying to do that requires adding predecessors like
> this?
>

Committing an edge insertion that ends up adding a new bb.