Re: [RFC] Contributing tree-ssa to mainline

[Joe Buck <Joe dot Buck at synopsys dot COM>]

On Fri, Jan 16, 2004 at 11:10:14PM -0700, law@redhat.com wrote:
> OK.  Let's take everything you've said as a given and let's ponder what
> actually has been done with Ada to make it work with already existing
> infrastructure mainline.  Specifically function at a time mode.  We've had
> function at a time mode for a few years now, but yet we still have seen
> little movement in the Ada front-end to support that mode.
> 
> Given the lack of movement on that front, how can we realistically expect
> any movement on something like tree-ssa?  Particularly when tree-ssa
> depends on function at a time mode?

Well, if we go ahead and release a tree-ssa GCC, and it's a big success
and clearly superior, to the point where fewer and fewer developers are
left who are interested in supporting the "old" GCC, at some point point
the pressure builds from knowledgeable GNAT users for a tree-ssa based
implementation, and the motivation will increase to respond to that
pressure.

What I'm hearing is that the Ada folks don't think that going to tree-ssa
and leaving them behind is a problem, so I'm willing to take them at their
word.

> Realistically, if we are going to make tree-ssa a complete non-starter
> because the Ada front-end isn't going to work and its maintainers are
> not showing any willingness to put forth the effort to make it work with
> already existing infrastructure, then, well, why bother with tree-ssa
> at all.  I'll take my time and effort to some other non-GCC project
> where I can actually make a difference.

I very much want to see a tree-ssa based GCC, and delays in converting the
Ada front end should not affect this (though they might require us to keep
the 3.4.x infrastructure around for longer).