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Re: What to remove after tree-ssa is merged?
- From: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
- To: paul at codesourcery dot com
- Cc: gcc at gcc dot gnu dot org
- Date: Wed, 4 Feb 04 16:58:21 EST
- Subject: Re: What to remove after tree-ssa is merged?
I fail to see how this is a problem. The frontend passes complete
functions to the optimizer. I agree that PLACEHOLDER_EXPR is a very
useful in the frontend when building trees. However I can't see how it
is of any use once the tree has been built.
Once the optimizers see a function, haven't we already determined all
uses of these expressions? Do you have any examples of the when an
optimier would unexpectedly decide it needs to use one of these
expressions?
I suspect we're saying the same thing: you won't find PLACEHOLDER_EXPR
in anything that comes from *statements*, but they will remain in the
trees describing *types*. The optimizer wouldn't see them, but the
Dwarf output routines would, for example.