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Re: [tree-ssa] crash in coalesce_abnormal_edges, merge frommainline?
On Wed, 2003-09-10 at 12:30, Andrew MacLeod wrote:
> On Wed, 2003-09-10 at 11:32, Daniel Berlin wrote:
> Looking at each place where may_propagate_copy() is called, in virtually
> every instance that matters, we are processing the arguments of a PHI,
> which means have access to the edge that arguement comes across right
> there on the spot... so we could just check the flag on the edge and not
> do the copy propagate based on that.. Then we dont have this auxillary
> bit hanging around.
>
> I think it can be done, and it ought to work... Thoguhts? Wasn't there
> originally something else we were using this for?
>
> I'm going to give it a try right now.
>
Ah, of course the drawback is that you wont be able to propagate it in
all places, so you wont actually get rid of all copies, so you might end
up worse off in some cases... Im not sure.
Of course, that means it'll only affect variables that you couldn't
copy propagate at all before this, so you'll be able to do some of the
copy props... Is it generally a good or bad idea to do as many as
possible knowing you can't do them all?
Andrew