+static ir_node *belower_skip_proj(ir_node *irn) {
+ while(is_Proj(irn))
+ irn = get_Proj_pred(irn);
+ return irn;
+}
+
+static void gen_assure_different_pattern(ir_node *irn, ir_node *other_different, constraint_env_t *env) {
+ be_irg_t *birg = env->birg;
+ pset *op_set = env->op_set;
+ const arch_env_t *arch_env = birg->main_env->arch_env;
+ ir_node *block = get_nodes_block(irn);
+ const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, other_different, -1);
+ ir_node *in[2], *keep, *cpy;
+ op_copy_assoc_t key, *entry;
+ FIRM_DBG_REGISTER(firm_dbg_module_t *mod, "firm.be.lower");
+
+ if (arch_irn_is(arch_env, other_different, ignore) || ! mode_is_datab(get_irn_mode(other_different))) {
+ DBG((mod, LEVEL_1, "ignore constraint for %+F because other_irn is ignore or not a datab node\n", irn));
+ return;
+ }
+
+ /* Make a not spillable copy of the different node */
+ /* this is needed because the different irn could be */
+ /* in block far far away */
+ /* The copy is optimized later if not needed */
+
+ cpy = be_new_Copy(cls, birg->irg, block, other_different);
+ be_node_set_flags(cpy, BE_OUT_POS(0), arch_irn_flags_dont_spill);
+
+ in[0] = irn;
+ in[1] = cpy;
+
+ /* Add the Keep resp. CopyKeep and reroute the users */
+ /* of the other_different irn in case of CopyKeep. */
+ if (get_n_out_edges(other_different) == 0) {
+ keep = be_new_Keep(cls, birg->irg, block, 2, in);
+ }
+ else {
+ keep = be_new_CopyKeep_single(cls, birg->irg, block, cpy, irn, get_irn_mode(other_different));
+ be_node_set_reg_class(keep, 1, cls);
+ }
+
+ /* let the copy point to the other_different irn */
+ set_irn_n(cpy, 0, other_different);
+
+ /* insert copy and keep into schedule */
+ assert(sched_is_scheduled(irn) && "need schedule to assure constraints");
+ sched_add_before(belower_skip_proj(irn), cpy);
+ sched_add_after(irn, keep);
+
+ /* insert the other different and it's copies into the set */
+ key.op = other_different;
+ key.copies = NULL;
+ entry = pset_find(op_set, &key, nodeset_hash(other_different));
+
+ if (! entry) {
+ entry = obstack_alloc(&env->obst, sizeof(*entry));
+ entry->copies = pset_new_ptr_default();
+ entry->op = other_different;
+ }
+
+ /* insert copy */
+ pset_insert_ptr(entry->copies, cpy);
+
+ /* insert keep in case of CopyKeep */
+ if (be_is_CopyKeep(keep))
+ pset_insert_ptr(entry->copies, keep);
+
+ pset_insert(op_set, entry, nodeset_hash(other_different));
+
+ DBG((mod, LEVEL_1, "created %+F for %+F to assure should_be_different\n", keep, irn));
+}
+
+/**
+ * Checks if node has a should_be_different constraint in output
+ * and adds a Keep then to assure the constraint.
+ */
+static void assure_different_constraints(ir_node *irn, constraint_env_t *env) {
+ const arch_register_req_t *req;
+ arch_register_req_t req_temp;
+
+ req = arch_get_register_req(env->birg->main_env->arch_env, &req_temp, irn, -1);
+
+ if (req) {
+ if (arch_register_req_is(req, should_be_different)) {
+ gen_assure_different_pattern(irn, req->other_different, env);
+ }
+ else if (arch_register_req_is(req, should_be_different_from_all)) {
+ int i, n = get_irn_arity(belower_skip_proj(irn));
+ for (i = 0; i < n; i++) {
+ gen_assure_different_pattern(irn, get_irn_n(belower_skip_proj(irn), i), env);
+ }
+ }
+ }
+}
+
+
+
+/**
+ * Calls the functions to assure register constraints.
+ *
+ * @param irn The node to be checked for lowering
+ * @param walk_env The walker environment
+ */
+static void assure_constraints_walker(ir_node *irn, void *walk_env) {
+ if (is_Block(irn))
+ return;
+
+ if (mode_is_datab(get_irn_mode(irn)))
+ assure_different_constraints(irn, walk_env);
+
+ return;
+}
+
+
+