On Mon, Aug 22, 2011 at 9:08 AM, Joern Rennecke <amyl...@spamcop.net> wrote: > Quoting Richard Guenther <richard.guent...@gmail.com>: > >>> So are you saying that we should remove the recursive nature of the >>> rtx_cost/targetm.rtx_costs interface, and have the backend handle any >>> recursion itself? I.e. targetm.rtx_costs only ever sees a complete >>> (but perhaps invalid) instruction pattern? Or would you still keep >>> the current recursion? >> >> I would say yes to that - kill the recursion. > > But the recursion is already optional. If you don't want to use recursion > for your port, just make the rtx_costs hook return true. > There is no need to break ports that are OK to use the recursion in > rtlanal.c > partially or in whole.
Exactly. I don't understand the disagreement about recursion. For instance, the rs6000 port explicitly returns true or false for rtx_costs as necessary for its computation. If a port wants to compute rtx_costs without recursion, it already has that control. Thanks, David
