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Re: [sa]: Revert partial def stuff, use fake variables instead




On Tue, 21 Dec 2004, Daniel Berlin wrote:



On Tue, 21 Dec 2004, Jeffrey A Law wrote:

On Tue, 2004-12-21 at 08:02 -0500, Diego Novillo wrote:
Jeffrey A Law wrote:

Those are functionally equivalent.  In a sane world (and our aliasing
code is *FAR* from sane) the most we should have to do is tell the
aliasing code that we have a new pointer and it points to X.

Which is *exactly* what I've been saying.  We were missing the
capability of telling that to the aliasing code.  I added that on the
cleanup branch.  If you are removing type tags, then we won't have to
update those, but you will still need to have glue code to let the
optimizers inform the aliasing code of changes.
With the rewrite, it's trivial to handle the changes ivopts makes --
largely because ivopts doesn't change the aliasing information, it
just adds a new pointer to a known location.

This is all we told zdenek to do now.

Just to clarify, we have told zdenek to add a new tag specifying exactly what the new pointer points-to.
Which is exactly what you are saying he should do as well.
He doesn't want to have to do that.


So i believe we are all in violent agreement except for zdenek.
:)



Part of the fundamental problem is the way our aliasing code works right
now -- you have to effectively re-run the entire alias analysis pass
after the seemingly trivial actions of ivopts.

No you don't, you just need to tell it about the new pointer.


IE create a new tag with the location as it's points-to location.


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