[tree-ssa] PATCH: Feedback-based prefetching

[Diego Novillo]

On Thu, 2003-12-11 at 19:41, Zdenek Dvorak wrote:

> > As I understand it, the tree-ssa branch is the current branch for "new 
> > development".  I
> > can't add new optimizations to the 3.4 branch any more, and I have been 
> > told that
> > tree-ssa will become the 3.5 compiler.
> 
> yes, but this does not mean that it is a development branch for any
> unrelated stuff.  Of course I am not the authority here, but IMHO this
> can wait till the mainline is open.
> 
That's right.  The SSA branch is a repository for SSA-based optimizers. 
Since the plan is to try and merge the branch into mainline for the 3.5
release, we are working very hard at stabilizing the branch and
implementing enough functionality to justify merging all the SSA work
into mainline.

You will notice that not even all the SSA-related work is going into the
main branch.  Planned work that is too experimental or needs to be done
in phases will likely go in sub-branches (e.g. the vectorization and
loop optimization passes).

We have agreed to host some patches that are considered basic
improvements or fixes that cannot be added to mainline at this stage. 
However, we also have to be careful, if a patch is too disruptive or
adds completely unrelated optimizations, then evaluating the quality of
the SSA passes on their own will become increasingly difficult, or even
impossible.

Finally, there is no guarantee that tree-ssa will be in 3.5.  We have
not beaten the mainline compiler in all areas yet.


Diego.