+ /*
+ If the current node is a barrier toggle the silent flag.
+ If we are in the start block, we are ought to be silent at the beginning,
+ so the toggling activates the constraint handling but skips the barrier.
+ If we are in the end block we handle the in requirements of the barrier
+ and set the rest to silent.
+ */
+ if(be_is_Barrier(irn))
+ *silent = !*silent;
+
+ if(be_silent)