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Re: Machine dependent Tree optimization?
"Bingfeng Mei" <email@example.com> writes:
> Of couse, for processors without long/short instructions, this copy
> propagation is benefiical for performance by reducing unnecessary
> dependency. Therefore, whether to apply this copy propagation is machine
> dependent to some degree.
> What I do now is to add some check in tree-ssa-copy.c and tree-ssa-dom.c
> for our target. But this is not very clean. My question is whether there
> is better way to implement such machine-dependent tree-level
> optimization (like hooks in RTL level). I believe there are other
> processors that have the similar problem. What is common solution?
This should normally be done at the RTL level by making long constants
more expensive in RTX_COSTS. With luck that will let gcse pick this