+ if (! keep_perm) {
+ sched_remove(irn);
+ kill_node(irn);
+ }
+}
+
+
+
+static int has_irn_users(const ir_node *irn) {
+ return get_irn_out_edge_first_kind(irn, EDGE_KIND_NORMAL) != 0;
+}
+
+/**
+ * Skip all Proj nodes.
+ */
+static INLINE ir_node *belower_skip_proj(ir_node *irn) {
+ while(is_Proj(irn))
+ irn = get_Proj_pred(irn);
+ return irn;
+}
+
+static ir_node *find_copy(constraint_env_t *env, ir_node *irn, ir_node *op) {
+ const arch_env_t *arch_env = be_get_birg_arch_env(env->birg);
+ ir_node *block = get_nodes_block(irn);
+ ir_node *cur_node;
+
+ for (cur_node = sched_prev(irn);
+ ! is_Block(cur_node) && be_is_Copy(cur_node) && get_nodes_block(cur_node) == block;
+ cur_node = sched_prev(cur_node))
+ {
+ if (be_get_Copy_op(cur_node) == op && arch_irn_is(arch_env, cur_node, dont_spill))
+ return cur_node;
+ }
+
+ return NULL;
+}
+
+static void gen_assure_different_pattern(ir_node *irn, ir_node *other_different, constraint_env_t *env) {
+ be_irg_t *birg = env->birg;
+ ir_graph *irg = be_get_birg_irg(birg);
+ pset *op_set = env->op_set;
+ const arch_env_t *arch_env = be_get_birg_arch_env(birg);
+ 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;
+ DEBUG_ONLY(firm_dbg_module_t *mod = env->dbg;)
+
+ 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 */
+
+ /* check if already exists such a copy in the schedule immediately before */
+ cpy = find_copy(env, belower_skip_proj(irn), other_different);
+ if (! cpy) {
+ cpy = be_new_Copy(cls, irg, block, other_different);
+ be_node_set_flags(cpy, BE_OUT_POS(0), arch_irn_flags_dont_spill);
+ DBG((mod, LEVEL_1, "created non-spillable %+F for value %+F\n", cpy, other_different));
+ }
+ else {
+ DBG((mod, LEVEL_1, "using already existing %+F for value %+F\n", cpy, other_different));
+ }
+
+ 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 (has_irn_users(other_different)) {
+ keep = be_new_CopyKeep_single(cls, irg, block, cpy, irn, get_irn_mode(other_different));
+ be_node_set_reg_class(keep, 1, cls);
+ }
+ else {
+ keep = be_new_Keep(cls, irg, block, 2, in);
+ }
+
+ DBG((mod, LEVEL_1, "created %+F(%+F, %+F)\n\n", keep, irn, cpy));
+
+ /* insert copy and keep into schedule */
+ assert(sched_is_scheduled(irn) && "need schedule to assure constraints");
+ if (! sched_is_scheduled(cpy))
+ 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;
+ entry = pset_find(op_set, &key, hash_irn(other_different));
+
+ if (! entry) {
+ entry = obstack_alloc(&env->obst, sizeof(*entry));
+ ir_nodeset_init(&entry->copies);
+ entry->op = other_different;
+ entry->cls = cls;
+ }
+
+ /* insert copy */
+ ir_nodeset_insert(&entry->copies, cpy);
+
+ /* insert keep in case of CopyKeep */
+ if (be_is_CopyKeep(keep)) {
+ ir_nodeset_insert(&entry->copies, keep);
+ }
+
+ pset_insert(op_set, entry, hash_irn(other_different));
+}
+
+/**
+ * Checks if node has a must_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;
+ const arch_env_t *arch_env = be_get_birg_arch_env(env->birg);
+ ir_node *skipped_irn = belower_skip_proj(irn);
+
+ req = arch_get_register_req(arch_env, irn, -1);
+
+ if (arch_register_req_is(req, must_be_different)) {
+ const unsigned other = req->other_different;
+ int i;
+
+ if (arch_register_req_is(req, should_be_same)) {
+ const unsigned same = req->other_same;
+
+ if (is_po2(other) && is_po2(same)) {
+ int idx_other = ntz(other);
+ int idx_same = ntz(same);
+
+ /*
+ * We can safely ignore a should_be_same x must_be_different y
+ * IFF both inputs are equal!
+ */
+ if (get_irn_n(skipped_irn, idx_other) == get_irn_n(skipped_irn, idx_same)) {
+ return;
+ }
+ }
+ }
+ for (i = 0; 1U << i <= other; ++i) {
+ if (other & (1U << i)) {
+ ir_node *different_from = get_irn_n(skipped_irn, i);
+ gen_assure_different_pattern(irn, different_from, 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 (sched_is_scheduled(irn) && mode_is_datab(get_irn_mode(irn)))
+ assure_different_constraints(irn, walk_env);
+}
+
+/**
+ * Melt all copykeeps pointing to the same node
+ * (or Projs of the same node), copying the same operand.
+ */
+static void melt_copykeeps(constraint_env_t *cenv) {
+ be_irg_t *birg = cenv->birg;
+ ir_graph *irg = be_get_birg_irg(birg);
+ op_copy_assoc_t *entry;
+
+ /* for all */
+ foreach_pset(cenv->op_set, entry) {
+ int idx, num_ck;
+ ir_node *cp;
+ struct obstack obst;
+ ir_nodeset_iterator_t iter;
+ ir_node **ck_arr, **melt_arr;
+
+ obstack_init(&obst);
+
+ /* collect all copykeeps */
+ num_ck = idx = 0;
+ foreach_ir_nodeset(&entry->copies, cp, iter) {
+ if (be_is_CopyKeep(cp)) {
+ obstack_grow(&obst, &cp, sizeof(cp));
+ ++num_ck;
+ }
+#ifdef KEEP_ALIVE_COPYKEEP_HACK
+ else {
+ set_irn_mode(cp, mode_ANY);
+ keep_alive(cp);
+ }
+#endif /* KEEP_ALIVE_COPYKEEP_HACK */
+ }
+
+ /* compare each copykeep with all other copykeeps */
+ ck_arr = (ir_node **)obstack_finish(&obst);
+ for (idx = 0; idx < num_ck; ++idx) {
+ ir_node *ref, *ref_mode_T;
+
+ if (ck_arr[idx]) {
+ int j, n_melt;
+ ir_node **new_ck_in;
+ ir_node *new_ck;
+ ir_node *sched_pt = NULL;
+
+ n_melt = 1;
+ ref = ck_arr[idx];
+ ref_mode_T = skip_Proj(get_irn_n(ref, 1));
+ obstack_grow(&obst, &ref, sizeof(ref));
+
+ DBG((cenv->dbg, LEVEL_1, "Trying to melt %+F:\n", ref));
+
+ /* check for copykeeps pointing to the same mode_T node as the reference copykeep */
+ for (j = 0; j < num_ck; ++j) {
+ ir_node *cur_ck = ck_arr[j];
+
+ if (j != idx && cur_ck && skip_Proj(get_irn_n(cur_ck, 1)) == ref_mode_T) {
+ obstack_grow(&obst, &cur_ck, sizeof(cur_ck));
+ ir_nodeset_remove(&entry->copies, cur_ck);
+ DBG((cenv->dbg, LEVEL_1, "\t%+F\n", cur_ck));
+ ck_arr[j] = NULL;
+ ++n_melt;
+ sched_remove(cur_ck);
+ }
+ }
+ ck_arr[idx] = NULL;
+
+ /* check, if we found some candidates for melting */
+ if (n_melt == 1) {
+ DBG((cenv->dbg, LEVEL_1, "\tno candidate found\n"));
+ continue;
+ }
+
+ ir_nodeset_remove(&entry->copies, ref);
+ sched_remove(ref);
+
+ melt_arr = (ir_node **)obstack_finish(&obst);
+ /* melt all found copykeeps */
+ NEW_ARR_A(ir_node *, new_ck_in, n_melt);
+ for (j = 0; j < n_melt; ++j) {
+ new_ck_in[j] = get_irn_n(melt_arr[j], 1);
+
+ /* now, we can kill the melted keep, except the */
+ /* ref one, we still need some information */
+ if (melt_arr[j] != ref)
+ kill_node(melt_arr[j]);
+ }
+
+#ifdef KEEP_ALIVE_COPYKEEP_HACK
+ new_ck = be_new_CopyKeep(entry->cls, irg, get_nodes_block(ref), be_get_CopyKeep_op(ref), n_melt, new_ck_in, mode_ANY);
+ keep_alive(new_ck);
+#else
+ new_ck = be_new_CopyKeep(entry->cls, irg, get_nodes_block(ref), be_get_CopyKeep_op(ref), n_melt, new_ck_in, get_irn_mode(ref));
+#endif /* KEEP_ALIVE_COPYKEEP_HACK */
+
+ /* set register class for all kept inputs */
+ for (j = 1; j <= n_melt; ++j)
+ be_node_set_reg_class(new_ck, j, entry->cls);
+
+ ir_nodeset_insert(&entry->copies, new_ck);
+
+ /* find scheduling point */
+ sched_pt = ref_mode_T;
+ do {
+ /* just walk along the schedule until a non-Keep/CopyKeep node is found */
+ sched_pt = sched_next(sched_pt);
+ } while (be_is_Keep(sched_pt) || be_is_CopyKeep(sched_pt));
+
+ sched_add_before(sched_pt, new_ck);
+ DBG((cenv->dbg, LEVEL_1, "created %+F, scheduled before %+F\n", new_ck, sched_pt));
+
+ /* finally: kill the reference copykeep */
+ kill_node(ref);
+ }
+ }
+
+ obstack_free(&obst, NULL);
+ }