[PATCH]: Implement must-def kill operand
Diego Novillo
dnovillo@redhat.com
Wed Oct 20 21:04:00 GMT 2004
On Wed, 2004-10-20 at 16:55, Daniel Berlin wrote:
> That will, in turn, mark the *feeders* of the phi as necessary, because
> they will be added to the worklist, and propagate_necessity doesn't
> know that it doesn't need to mark the feeders unless they are phi
> nodes, thus you will miss dead code being eliminated.
>
Ah, good point. Sigh. I think I'm about to ask you to just let the
regular renamer run and insert needed PHIs, but I agree that PHI node
churn should be avoided.
How much additional code are we talking about? A good chunk of the
algorithm you described already exists in DCE. Can it be factored?
Diego.
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