+/**
+ * Returns backarray if the node can have backedges, else returns
+ * NULL.
+ */
+static INLINE int *get_backarray(ir_node *n) {
+ int *ba = mere_get_backarray(n);
+
+ if (ba) {
+ int bal = ARR_LEN(ba); /* avoid makro expansion in assertion. */
+ int inl = ARR_LEN(get_irn_in(n)) -1; /* Use get_irn_in -- sensitive to view! */
+ assert(bal == inl && "backedge array with faulty length");
+ }
+
+ return ba;
+}
+
+/**
+ * Returns nin-zero if node has no backarray, or
+ * if size of backarray == size of in array.
+ */
+static INLINE int legal_backarray (ir_node *n) {
+ int *ba = mere_get_backarray(n);
+ if (ba && (ARR_LEN(ba) != ARR_LEN(get_irn_in(n))-1)) /* Use get_irn_in -- sensitive to view! */
+ return 0;
+ return 1;
+}
+
+
+void fix_backedges(struct obstack *obst, ir_node *n) {
+ int *arr = mere_get_backarray(n);
+ opcode opc;
+
+ if (! arr)
+ return;
+
+ if (ARR_LEN(arr) != ARR_LEN(get_irn_in(n))-1) {
+ arr = new_backedge_arr(obst, ARR_LEN(get_irn_in(n))-1);
+
+ opc = get_irn_opcode(n);
+ if (opc == iro_Phi)
+ n->attr.phi_backedge = arr;
+ else if (opc == iro_Block) {
+ if (!get_interprocedural_view())
+ n->attr.block.backedge = arr;
+ else
+ n->attr.block.cg_backedge = arr;
+ }
+ else if (opc == iro_Filter)
+ n->attr.filter.backedge = arr;
+ }
+
+ assert(legal_backarray(n));
+
+ /* @@@ more efficient in memory consumption, not possible with
+ array implementation.
+ if (ARR_LEN(arr) < ARR_LEN(get_irn_in(n))-1) {
+ ARR_SETLEN(int, arr, ARR_LEN(get_irn_in(n))-1);
+ }*/
+}
+
+int is_inter_backedge(ir_node *n, int pos) {
+ int res;
+ int rem = get_interprocedural_view();
+ set_interprocedural_view(0);
+ res = is_backedge(n, pos);
+ set_interprocedural_view(rem);
+ return res;
+}
+
+int is_intra_backedge(ir_node *n, int pos) {
+ int res;
+ int rem = get_interprocedural_view();
+ set_interprocedural_view(1);
+ res = is_backedge(n, pos);
+ set_interprocedural_view(rem);
+ return res;
+}
+
+
+/* Returns non-zero if the predecessor pos is a backedge. */
+int is_backedge (ir_node *n, int pos) {