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Re: [RFC] Contributing tree-ssa to mainline
- From: Theodore Papadopoulo <Theodore dot Papadopoulo at sophia dot inria dot fr>
- To: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
- Cc: hubicka at ucw dot cz, gcc at gcc dot gnu dot org
- Date: Mon, 19 Jan 2004 14:00:54 +0100
- Subject: Re: [RFC] Contributing tree-ssa to mainline
kenner@vlsi1.ultra.nyu.edu said:
> A case I know about in Ada is check elimination. Because the default
> for Ada is enabling checking, it's quite important to eliminate checks
> that can be proven not to fail. Theoretically, a lot this could be
> language-independent optimizers by value range propagation and related
> optimizations. But the front-end can do a much better job because it
> has information only it knows. Moreover, by suppressing the check
> before generating any code for it, compilation time is reduced. I
> think this is clearly the proper place for that optimization.
AFAIK, tree-ssa would be beneficial in this situation. By making the
check elimination work on GIMPLE (I hope it is the proper place),
this would remove this from the ADA front-end and generalize to other
languages. I assume that the sole introduction of optimization on
trees allow you to move some code out of the front-end to the tree
optimization passes of tree-ssa.
That being said, as an exterior observer, what I can say is that we
have seen quite a few major contributors switching to tree-ssa recently...
This is surely partially because gcc-3.4 was in stage 3, but the move
has been more marked than for previous releases
IMHO.
Having the work-forces (rougthly) splitted in two is not a good thing IMO.
That should be considered...
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Theodore Papadopoulo
Email: Theodore.Papadopoulo@sophia.inria.fr Tel: (33) 04 92 38 76 01
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