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Re: [RFC] fold Reorganization Plan
> I don't know whether these operations should be part of the same SSA
> optimization or not. #2 is more of a constant propagation kind of
> thing I guess. #1 is the kind of thing that has made const-fold so
> complicated. #1 is the important thing to add to the SSA optimizers,
> isn't it?
Yes.
In fact, i'm working on making GVN-PRE do some reassociation as part of
it's value numbering in 4.1, so that we can detect that given
a = b + c
d = a + e
and
a = b + e
d = a + c
that d has the same value in both cases.
This is more or less done through value expression chasing, rather than
SSA_NAME_DEF_STMT chasing (because we already know the "value
expression" for b + e, which is something like ValueNumber34 +
ValueNumber65)
>
> nathan