Re: Loop optimizer issues

[Diego Novillo <dnovillo at redhat dot com>]

How about this:

     1. We identify generic bits of infrastructure that are
        IL-independent and merge those into tree-ssa.
     2. RTL optimizations are either converted to use the tree-ssa
        framework or deemed useful only for RTL, in which case I guess
        we wouldn't lose anything by merging them.

However, I would like to see these bits in independent chunks, if
possible.  One alternative that I've been thinking about is to create a
sub-branch of tree-ssa to deal exclusively with loop optimizations and
vectorization:

     1. The tree-ssa branch would like to become 3.5 in the near
        future.  It already contains a lot of experimental code that I
        would very much like to stabilize.  Adding even more
        experimental code at this stage seems a bit risky to me.
     2. Since work for loop optimizers and vectorization has just
        started, it is unclear how much of it will be ready for 3.5.
     3. A sub-branch of tree-ssa is no different than a mainline
        branch.  Code that's ready for 3.5, can be merged at the same
        time as tree-ssa.

Thoughts?


Diego.