Re: [tree-ssa] AST optimizer in C++?

[Diego Novillo <dnovillo at redhat dot com>]

On Sun, 25 Aug 2002, Chris Lattner wrote:

> In my mind, one of two things would make sense:
> 
> 1. Change SIMPLE to incorporate some of the better ideas from LLVM, while
>    leaving stuff people don't like alone.
> 2. Replace SIMPLE with LLVM.  If LLVM looks nice, and having a mature C++
>    implementation would also help, I certainly would not be opposed to
>    this.  I'm sure many people would though, and I'm explicitly not
>    pushing for this.
> 
I agree with #1.  We chose to go with SIMPLE because it
represented an evolutionary approach wrt the existing
implementation.  Evolution is much more civilized than
revolution.

I've seen several neat ideas in LLVM.  Incorporating some of them
in GCC would be great.  And the tree-ssa branch is perfect for
that kind of experimentation.

> Do you have any idea what kinds of things are possible in simple that you
> don't think would be possible (or pleasant) in LLVM?  I'd like to get an
> idea if there is something that would be hard to do in LLVM, but is easy
> in SIMPLE (to figure out how much overlap there is).
> 
We have just started doing things in SIMPLE.  It is still
incomplete and we haven't found the really hard problems.  All
the work that we are doing is based on published algorithms and
designs, so it's relatively straightforward for people not
familiar with GCC to jump in and see how things are developing.


Diego.