Hi Jeff: > This seems better suited as a generic optimization than hidden away in a > backend. > > AFAICT you're just noticing a word of the output operand is dead and eliding > the load/store for that word. > > In fact, I'm a bit surprised nothing has optimized this away by the time > reload/LRA is done. You might spend some time walking through lower-subreg > to see if it can be easily extended to handle your case.
Agree, I will take a look for lower-subreg and LRA. However this patch still need for other target, this patch is ok for trunk?
