+/**
+ * Creates a be_Return for a Return node.
+ *
+ * @param @env the abi environment
+ * @param irn the Return node or NULL if there was none
+ * @param bl the block where the be_Retun should be placed
+ * @param mem the current memory
+ * @param n_res number of return results
+ */
+static ir_node *create_be_return(be_abi_irg_t *env, ir_node *irn, ir_node *bl, ir_node *mem, int n_res) {
+ be_abi_call_t *call = env->call;
+ const arch_isa_t *isa = env->birg->main_env->arch_env->isa;
+
+ pmap *reg_map = pmap_create();
+ ir_node *keep = pmap_get(env->keep_map, bl);
+ int in_max;
+ ir_node *ret;
+ int i, n;
+ ir_node **in;
+ ir_node *stack;
+ const arch_register_t **regs;
+ pmap_entry *ent ;
+
+ /*
+ get the valid stack node in this block.
+ If we had a call in that block there is a Keep constructed by process_calls()
+ which points to the last stack modification in that block. we'll use
+ it then. Else we use the stack from the start block and let
+ the ssa construction fix the usage.
+ */
+ stack = be_abi_reg_map_get(env->regs, isa->sp);
+ if (keep) {
+ ir_node *bad = new_r_Bad(env->birg->irg);
+ stack = get_irn_n(keep, 0);
+ set_nodes_block(keep, bad);
+ set_irn_n(keep, 0, bad);
+ // exchange(keep, new_r_Bad(env->birg->irg));
+ }
+
+ /* Insert results for Return into the register map. */
+ for(i = 0; i < n_res; ++i) {
+ ir_node *res = get_Return_res(irn, i);
+ be_abi_call_arg_t *arg = get_call_arg(call, 1, i);
+ assert(arg->in_reg && "return value must be passed in register");
+ pmap_insert(reg_map, (void *) arg->reg, res);
+ }
+
+ /* Add uses of the callee save registers. */
+ pmap_foreach(env->regs, ent) {
+ const arch_register_t *reg = ent->key;
+ if(arch_register_type_is(reg, callee_save) || arch_register_type_is(reg, ignore))
+ pmap_insert(reg_map, ent->key, ent->value);
+ }
+
+ be_abi_reg_map_set(reg_map, isa->sp, stack);
+
+ /* Make the Epilogue node and call the arch's epilogue maker. */
+ create_barrier(env, bl, &mem, reg_map, 1);
+ call->cb->epilogue(env->cb, bl, &mem, reg_map);
+
+ /*
+ Maximum size of the in array for Return nodes is
+ return args + callee save/ignore registers + memory + stack pointer
+ */
+ in_max = pmap_count(reg_map) + n_res + 2;
+
+ in = obstack_alloc(&env->obst, in_max * sizeof(in[0]));
+ regs = obstack_alloc(&env->obst, in_max * sizeof(regs[0]));
+
+ in[0] = mem;
+ in[1] = be_abi_reg_map_get(reg_map, isa->sp);
+ regs[0] = NULL;
+ regs[1] = isa->sp;
+ n = 2;
+
+ /* clear SP entry, since it has already been grown. */
+ pmap_insert(reg_map, (void *) isa->sp, NULL);
+ for(i = 0; i < n_res; ++i) {
+ ir_node *res = get_Return_res(irn, i);
+ be_abi_call_arg_t *arg = get_call_arg(call, 1, i);
+
+ in[n] = be_abi_reg_map_get(reg_map, arg->reg);
+ regs[n++] = arg->reg;
+
+ /* Clear the map entry to mark the register as processed. */
+ be_abi_reg_map_set(reg_map, arg->reg, NULL);
+ }
+
+ /* grow the rest of the stuff. */
+ pmap_foreach(reg_map, ent) {
+ if(ent->value) {
+ in[n] = ent->value;
+ regs[n++] = ent->key;
+ }
+ }
+
+ /* The in array for the new back end return is now ready. */
+ ret = be_new_Return(irn ? get_irn_dbg_info(irn) : NULL, env->birg->irg, bl, n_res, n, in);
+
+ /* Set the register classes of the return's parameter accordingly. */
+ for(i = 0; i < n; ++i)
+ if(regs[i])
+ be_node_set_reg_class(ret, i, regs[i]->reg_class);
+
+ /* Free the space of the Epilog's in array and the register <-> proj map. */
+ obstack_free(&env->obst, in);
+ pmap_destroy(reg_map);
+
+ return ret;
+}
+