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Deprecating -f options?


Is there a standard process we use to eliminate -f options? or is it
more on a per options basis.

Im reworking out-of-ssa for 4.3 and there are a couple of options that
were initially added which I prefer to no longer support.

-ftree-combine-temps attempts to coalesce non-related ssa_names into a
single variable. (ie, combining A with B.)  I'm not sure this option
even functions right now.

-ftree-live-range-split  splits live ranges on exit from ssa.  This is
on by default, and in fact it is more work to NOT split unrelated live
ranges, and creates extra register pressure. 

Does anyone actually use either of these options?

Should anyone *really* want one or the other of these options, they
could both be implemented with a single pass to merge non-overlapping
local variable accesses, and don't have to be (and probably shouldn't
be) an integral part of out-of-ssa.

-ftree-ter is another one, but I'm not sure it should be deprecated yet.
Its always on right now, and I think you get really crappy code if you
turn it off. TER itself will be deprecated eventually, and then the
option will have to go.  (fyi, TER merges expressions on the way out of
ssa to let the current expanders see larger expressions and in produce
better initial instruction selections in RTL)

Andrew


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