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

> > The approach we use now does not interfere with the underlying
> > IR.  What it does is overlay a web of def-use/use-def pointers on
> Is there a reason that you'd like to have a SIMPLE form that is not in
> SSA?

Um, yes.
It artificially limits us to that representation.
Say later, someone wants to use some other form of SSA, or non-SSA 
(dependence flow graph, etc).
If you make it actually part of the trees, they now have to care about 
If it's just annotations, only what wants to look at those annotations 
look at it.

Plus, there are optimization passes that might not be run on SSA (some 
loop optimizations).

Once again, forcing SSA on the representation itself means they have to 
care about it (or you've limited when they can be run), while annotations 
have no such limitations.

There is no good reason to actually make it part of the form, other than 
having to insert copies yourself.  But all algorithms i've seen that are 
written to keep SSA form up to date do this anyway, or make it easy to do.

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