reduceop should always realize

tinygrad/engine/schedule.py

@@ -203,15 +203,15 @@ def _graph_schedule(outs:List[LazyBuffer], seen:Set[LazyBuffer]) -> Tuple[Defaul
           continue
         parents.extend(p.srcs)
     if forced_realize:
-      for rc in (prev_children:=realized_children.copy()):
+      for rc in realized_children.copy():
         rc_parents = deque(rc.srcs)
         while rc_parents:
           if (p:=rc_parents.pop().base).op is LoadOps.CONST or p.realized or p is r: continue
           if p in realizes or p.op in ReduceOps or p in reduce_for_op:
             del realized_children[rc]
             break
           rc_parents.extend(p.srcs)
-      if len(realized_children) < len(prev_children): realizes[r] = None
+      if len(realized_children) != 0: realizes[r] = None
     if len(realized_children) == 0:
       tr = r
       if can_chase: