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Re: [tree-ssa vs lno] who is right?
- From: law at redhat dot com
- To: Andrew MacLeod <amacleod at redhat dot com>
- Cc: Diego Novillo <dnovillo at redhat dot com>, Dale Johannesen <dalej at apple dot com>, gcc mailing list <gcc at gcc dot gnu dot org>
- Date: Fri, 26 Mar 2004 08:30:30 -0700
- Subject: Re: [tree-ssa vs lno] who is right?
- Reply-to: law at redhat dot com
In message <1080308082.12528.27.camel@p4>, Andrew MacLeod writes:
>I have some minor changes to copyrename in the queue, but I doubt it
>will affect this. Since there is a constant in the arguments of the PHI,
>it must have been renamed due to a copy between a temp and maxmin_Result
>elsewhere in the program. The hope was that we'd be able to get rid of
>the copy. Looks like not, unless one or more of the PHIs can be
>optimized away. :-)
I'd expect DOM to propagate the constants so that there were no uses
of maxmin_Result_140, maxmin_Result_142, then I'd expect DCE to zap the
useless PHIs.
Alternatively Zdenek's block trivial PHI removal code may zap them.
But again, I think step #1 is to figure out how we got them in the first
place.
jeff