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Re: [patch] Lno branch merge part 3 -- ssa form updatingimprovements
- From: Diego Novillo <dnovillo at redhat dot com>
- To: Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>
- Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 14 Jun 2004 22:48:58 -0400
- Subject: Re: [patch] Lno branch merge part 3 -- ssa form updatingimprovements
- Organization: Red Hat Canada
- References: <20040615023922.GA9582@atrey.karlin.mff.cuni.cz>
On Mon, 2004-06-14 at 22:39, Zdenek Dvorak wrote:
> this patch adds a possibility to handle ssa form updating without need
> to rewrite variables out of ssa form. The idea is to allow to violate
> the invariants of the ssa form temporarily and let a single ssa name
> have several definitions. A call to rewrite_ssa_into_ssa (running
> standard ssa creation algorithm just over those ssa names) then
> "repairs" the ssa form.
This description doesn't look like a good idea. But it's too brief to
really figure out what you are trying to do. Could you elaborate? Will
you make existing SSA_NAMEs disappear when you repair multiple
The fact that we have the program in an invalid SSA form, however
briefly, across two different modules seems like a recipe for disaster.
Could you describe what you are trying to do with an example? (don't
point me to the patch, please).