+
+static void check_out_edges(ir_node *irn, void *env) {
+ int i, j, pos;
+ int *pError = env;
+ int error = *pError;
+ int last = is_Block(irn) ? 0 : -1;
+
+ /* check forward: every input must have an out edge */
+ for (i = get_irn_arity(irn) - 1; i >= last; --i) {
+ ir_node *pred = get_irn_n(irn, i);
+
+ for (j = get_irn_n_outs(pred) - 1; j >= 0; --j) {
+ ir_node *user = get_irn_out_ex(pred, j, &pos);
+
+ if (user == irn && pos == i) {
+ break;
+ }
+ }
+ if (j < 0) {
+ ir_fprintf(stderr, "Missing out edge from %+F input %d to %+F", irn, i, pred);
+ ++error;
+ }
+ }
+
+ /* checking backward */
+ for (i = get_irn_n_outs(irn) - 1; i >= 0; --i) {
+ ir_node *user = get_irn_out_ex(irn, i, &pos);
+
+ if (get_irn_n(user, pos) != irn) {
+ ir_fprintf(stderr, "Spurious out edge from %+F output %d to %+F", irn, i, user);
+ ++error;
+ }
+ }
+ *pError = error;
+}
+
+/* verify outs edges. */
+void verify_outs(ir_graph *irg) {
+ int errors = 0;
+ irg_walk_graph(irg, NULL, check_out_edges, &errors);
+ if (errors > 0)
+ panic("Out edges are corrupt");
+}