On Mon, Aug 04, 2014 at 12:26:01PM +0200, Richard Biener wrote:
> I think that tree-ssa-forwprop.c already simplifies this in
> associate_plusminus with (T)(P + A) - (T)P -> (T)A. Well,
> maybe not - but then the code should be massages to handle it.
>
> Can you double-check and do that?
>
> Otherwise I agree with removing this (and other) "premature"
> optimizations scattered throughout the frontends (and convert.c).
IMHO a precondition of such changes is exactly verifying the middle-end
can perform those optimizations later on and if not, teaching the middle-end
to optimize that.
Jakub
