How to define "implicit extend"

[Richard Henderson]

On Fri, Dec 13, 2002 at 12:40:33AM +0100, devik wrote:
> Is there way to tell GCC that all registers can be zero_extended
> just by pretending they already are ?

Kind of, but you don't want to do that -- it'll get you into
more trouble than you want.  What you want is to add patterns
such that the composition of zero_extend and the original 
operation is visible to the combiner.


r~