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Re: [tree-ssa] Lazy updating of stmt operands
- From: Chris Lattner <sabre at nondot dot org>
- To: Andrew MacLeod <amacleod at redhat dot com>
- Cc: Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>,Jeff Law <law at redhat dot com>, gcc mailing list <gcc at gcc dot gnu dot org>
- Date: Fri, 12 Dec 2003 13:46:44 -0600 (CST)
- Subject: Re: [tree-ssa] Lazy updating of stmt operands
> > hardly; you still must scan all statements to find the uses, so I don't
> > see where you would want to get the extra efficiency.
> >
> Scanning stmts is very cheap.
You must not have run across programs that have PHI nodes with thousands
of operands...
> The uses/defs are all cached.
Don't caches take space?
> And if you do need it over a chain of optimizations, do it once, and
> then keep the info up to date/. You'll be a lot better off I think
Isn't that the whole idea?
-Chris
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