On 10/29/2010 05:08 PM, Georg Lay wrote:
As far as I understand the internals, peephole2 matches due to predicates and condition, it does not care for constraints (except for optional match_scratch)
Yes, I was referring as "using constraints in the define_insn". But you're dong that as far as I see.
Maybe it's better to write it as a split1 that works prior to reload instead of split2 that works after reload.
Yes, a split1 sounds much better. It will give much more freedom to reload and the register allocation to do exactly the liveness-based kind of optimization that you're doing with a peephole.
I don't know. match_scratch has the disadvantage that the input pattern will become a PARALLEL and is no more a single_set.
I don't understand why you mentioned match_scratch :) anyway note that a parallel of SET and CLOBBERs is a single_set.
Paolo
