-/* Returns true if the predesessor pos is a backedge. */
-bool is_backedge (ir_node *n, int pos) {
- int *ba = get_backarray (n);
- if (ba) return ba[pos];
- return false;
+/**
+ * Returns backarray if the node can have backedges, else returns
+ * NULL.
+ */
+static bitset_t *get_backarray(ir_node *n)
+{
+ bitset_t *ba = mere_get_backarray(n);
+
+#ifndef NDEBUG
+ if (ba) {
+ size_t bal = bitset_size(ba); /* avoid macro expansion in assertion. */
+ size_t inl = get_irn_arity(n);
+ assert(bal == inl && "backedge array with faulty length");
+ }
+#endif
+
+ return ba;
+}
+
+#ifndef NDEBUG
+/**
+ * Returns non-zero if node has no backarray, or
+ * if size of backarray == size of in array.
+ */
+static int legal_backarray(ir_node *n)
+{
+ bitset_t *ba = mere_get_backarray(n);
+ if (ba && (bitset_size(ba) != (unsigned) get_irn_arity(n)))
+ return 0;
+ return 1;
+}
+#endif
+
+void fix_backedges(struct obstack *obst, ir_node *n)
+{
+ bitset_t *arr = mere_get_backarray(n);
+ unsigned opc;
+ int arity;
+
+ if (! arr)
+ return;
+
+ arity = get_irn_arity(n);
+ if (bitset_size(arr) != (unsigned) arity) {
+ arr = new_backedge_arr(obst, arity);
+
+ opc = get_irn_opcode(n);
+ if (opc == iro_Phi)
+ n->attr.phi.u.backedge = arr;
+ else if (opc == iro_Block) {
+ n->attr.block.backedge = arr;
+ }
+ }
+
+ assert(legal_backarray(n));
+}
+
+/* Returns non-zero if the predecessor pos is a backedge. */
+int is_backedge(ir_node *n, int pos)
+{
+ bitset_t *ba = get_backarray(n);
+ if (ba)
+ return bitset_is_set(ba, pos);
+ return 0;