> As for copies, I think it would be a bad decision to stick only to > original (after the code selection) alternative and generate copies to > satisfy this alternative. For example, if pseudo got memory instead of > hard-register required by the alternative, it would be bad to generate a > copy (ld/st in this case) if memory is accepted by the insn.
Yes, spilling is a special case (see also PR19398). If something is spilled, "prereloads" could be rolled back for affected instructions and recomputed (possibly forcing no change on the constraints of other registers). > That is in brief how I see it and there are a lot of reload details > missed (like virtual register eliminations or addressing displacement > constraints etc). I suppose those would stay in reload? Michael, what were your intentions for the insn-sel branch? (Sorry to remind you of that :-P). Paolo
