+ /* only followers from our partition */
+ if (m->part != n->part)
+ continue;
+
+ if ((m->flagged & env->side) == 0) {
+ m->flagged |= env->side;
+
+ if (m->flagged != 3) {
+ /* visited the first time */
+ /* add m to unwalked not as first node (we might still need to
+ check for more follower node */
+ m->race_next = n->race_next;
+ n->race_next = m;
+ return 0;
+ }
+ /* else already visited by the other side and on the other list */
+ }
+ }
+ /* move n to walked */
+ env->unwalked = n->race_next;
+ n->race_next = env->walked;
+ env->walked = n;
+ env->index = 0;
+ }
+ return 1;
+} /* step */
+
+/**
+ * Clear the flags from a list and check for
+ * nodes that where touched from both sides.
+ *
+ * @param list the list
+ */
+static int clear_flags(node_t *list) {
+ int res = 0;
+ node_t *n;
+
+ for (n = list; n != NULL; n = n->race_next) {
+ if (n->flagged == 3) {
+ /* we reach a follower from both sides, this will split congruent
+ * inputs and make it a leader. */
+ follower_to_leader(n);
+ res = 1;
+ }
+ n->flagged = 0;
+ }
+ return res;
+} /* clear_flags */
+
+/**
+ * Split a partition by a local list using the race.
+ *
+ * @param pX pointer to the partition to split, might be changed!
+ * @param gg a (non-empty) node list
+ * @param env the environment
+ *
+ * @return a new partition containing the nodes of gg
+ */
+static partition_t *split(partition_t **pX, node_t *gg, environment_t *env) {
+ partition_t *X = *pX;
+ partition_t *X_prime;
+ list_head tmp;
+ step_env env1, env2, *winner;
+ node_t *g, *h, *node, *t;
+ int max_input, transitions;
+ unsigned n;
+ DEBUG_ONLY(static int run = 0;)
+
+ DB((dbg, LEVEL_2, "Run %d ", run++));
+ if (list_empty(&X->Follower)) {
+ /* if the partition has NO follower, we can use the fast
+ splitting algorithm. */
+ return split_no_followers(X, gg, env);
+ }
+ /* else do the race */
+
+ dump_partition("Splitting ", X);
+ dump_list("by list ", gg);
+
+ INIT_LIST_HEAD(&tmp);
+
+ /* Remove gg from X.Leader and put into g */
+ g = NULL;
+ for (node = gg; node != NULL; node = node->next) {
+ assert(node->part == X);
+ assert(node->is_follower == 0);
+
+ list_del(&node->node_list);
+ list_add_tail(&node->node_list, &tmp);
+ node->race_next = g;
+ g = node;
+ }
+ /* produce h */
+ h = NULL;
+ list_for_each_entry(node_t, node, &X->Leader, node_list) {
+ node->race_next = h;
+ h = node;
+ }
+ /* restore X.Leader */
+ list_splice(&tmp, &X->Leader);
+
+ env1.initial = g;
+ env1.unwalked = NULL;
+ env1.walked = NULL;
+ env1.index = 0;
+ env1.side = 1;
+
+ env2.initial = h;
+ env2.unwalked = NULL;
+ env2.walked = NULL;
+ env2.index = 0;
+ env2.side = 2;
+
+ for (;;) {
+ if (step(&env1)) {
+ winner = &env1;
+ break;
+ }
+ if (step(&env2)) {
+ winner = &env2;
+ break;
+ }
+ }
+ assert(winner->initial == NULL);
+ assert(winner->unwalked == NULL);
+
+ /* clear flags from walked/unwalked */
+ transitions = clear_flags(env1.unwalked);
+ transitions |= clear_flags(env1.walked);
+ transitions |= clear_flags(env2.unwalked);
+ transitions |= clear_flags(env2.walked);
+
+ dump_race_list("winner ", winner->walked);
+
+ /* Move walked_{winner} to a new partition, X'. */
+ X_prime = new_partition(env);
+ max_input = 0;
+ n = 0;
+ for (node = winner->walked; node != NULL; node = node->race_next) {
+ list_del(&node->node_list);
+ node->part = X_prime;
+ if (node->is_follower) {
+ list_add_tail(&node->node_list, &X_prime->Follower);
+ } else {
+ list_add_tail(&node->node_list, &X_prime->Leader);
+ ++n;
+ }
+ if (node->max_user_input > max_input)
+ max_input = node->max_user_input;
+ }
+ X_prime->n_leader = n;
+ X_prime->max_user_inputs = max_input;
+ X->n_leader -= X_prime->n_leader;
+
+ /* for now, copy the type info tag, it will be adjusted in split_by(). */
+ X_prime->type_is_T_or_C = X->type_is_T_or_C;
+
+ /*
+ * Even if a follower was not checked by both sides, it might have
+ * loose its congruence, so we need to check this case for all follower.
+ */
+ list_for_each_entry_safe(node_t, node, t, &X_prime->Follower, node_list) {
+ if (identity(node) == node) {
+ follower_to_leader(node);
+ transitions = 1;
+ }
+ }
+
+ check_partition(X);
+ check_partition(X_prime);
+
+ /* X' is the smaller part */
+ add_to_worklist(X_prime, env);
+
+ /*
+ * If there where follower to leader transitions, ensure that the nodes
+ * can be split out if necessary.
+ */
+ if (transitions) {
+ /* place partitions on the cprop list */
+ if (X_prime->on_cprop == 0) {
+ X_prime->cprop_next = env->cprop;
+ env->cprop = X_prime;
+ X_prime->on_cprop = 1;
+ }
+ }
+
+ dump_partition("Now ", X);
+ dump_partition("Created new ", X_prime);
+
+ /* we have to ensure that the partition containing g is returned */
+ if (winner == &env2) {
+ *pX = X_prime;
+ return X;
+ }
+
+ return X_prime;
+} /* split */
+
+/**
+ * Returns non-zero if the i'th input of a Phi node is live.
+ *
+ * @param phi a Phi-node
+ * @param i an input number
+ *
+ * @return non-zero if the i'th input of the given Phi node is live
+ */
+static int is_live_input(ir_node *phi, int i) {
+ if (i >= 0) {
+ ir_node *block = get_nodes_block(phi);
+ ir_node *pred = get_Block_cfgpred(block, i);
+ lattice_elem_t type = get_node_type(pred);
+
+ return type.tv != tarval_unreachable;
+ }
+ /* else it's the control input, always live */
+ return 1;
+} /* is_live_input */
+
+/**
+ * Return non-zero if a type is a constant.
+ */
+static int is_constant_type(lattice_elem_t type) {
+ if (type.tv != tarval_bottom && type.tv != tarval_top)
+ return 1;
+ return 0;
+} /* is_constant_type */
+
+/**
+ * Check whether a type is neither Top or a constant.
+ * Note: U is handled like Top here, R is a constant.
+ *
+ * @param type the type to check
+ */
+static int type_is_neither_top_nor_const(const lattice_elem_t type) {
+ if (is_tarval(type.tv)) {
+ if (type.tv == tarval_top)
+ return 0;
+ if (tarval_is_constant(type.tv))
+ return 0;
+ } else {
+ /* is a symconst */
+ return 0;
+ }
+ return 1;
+}
+
+/**
+ * Collect nodes to the touched list.
+ *
+ * @param list the list which contains the nodes that must be evaluated
+ * @param idx the index of the def_use edge to evaluate
+ * @param env the environment
+ */
+static void collect_touched(list_head *list, int idx, environment_t *env) {
+ node_t *x, *y;
+ int end_idx = env->end_idx;
+
+ list_for_each_entry(node_t, x, list, node_list) {
+ int num_edges;
+
+ if (idx == -1) {
+ /* leader edges start AFTER follower edges */
+ x->next_edge = x->n_followers + 1;
+ }
+ num_edges = get_irn_n_outs(x->node);
+
+ /* for all edges in x.L.def_use_{idx} */
+ while (x->next_edge <= num_edges) {
+ const ir_def_use_edge *edge = &x->node->out[x->next_edge];
+ ir_node *succ;
+
+ /* check if we have necessary edges */
+ if (edge->pos > idx)
+ break;
+
+ ++x->next_edge;
+
+ succ = edge->use;
+
+ /* ignore the "control input" for non-pinned nodes
+ if we are running in GCSE mode */
+ if (idx < end_idx && get_irn_pinned(succ) != op_pin_state_pinned)
+ continue;
+
+ y = get_irn_node(succ);
+ assert(get_irn_n(succ, idx) == x->node);
+
+ /* ignore block edges touching followers */
+ if (idx == -1 && y->is_follower)
+ continue;
+
+ if (is_constant_type(y->type)) {
+ ir_opcode code = get_irn_opcode(succ);
+ if (code == iro_Sub || code == iro_Eor || code == iro_Cmp)
+ add_to_cprop(y, env);
+ }
+
+ /* Partitions of constants should not be split simply because their Nodes have unequal
+ functions or incongruent inputs. */
+ if (type_is_neither_top_nor_const(y->type) &&
+ (! is_Phi(y->node) || is_live_input(y->node, idx))) {
+ add_to_touched(y, env);
+ }
+ }
+ }
+} /* collect_touched */
+
+/**
+ * Split the partitions if caused by the first entry on the worklist.
+ *
+ * @param env the environment
+ */
+static void cause_splits(environment_t *env) {
+ partition_t *X, *Z, *N;
+ int idx;
+
+ /* remove the first partition from the worklist */
+ X = env->worklist;
+ env->worklist = X->wl_next;
+ X->on_worklist = 0;
+
+ dump_partition("Cause_split: ", X);
+
+ /* combine temporary leader and follower list */
+ for (idx = -1; idx <= X->max_user_inputs; ++idx) {
+ /* empty the touched set: already done, just clear the list */
+ env->touched = NULL;
+
+ collect_touched(&X->Leader, idx, env);
+ collect_touched(&X->Follower, idx, env);
+
+ for (Z = env->touched; Z != NULL; Z = N) {
+ node_t *e;
+ node_t *touched = Z->touched;
+ unsigned n_touched = Z->n_touched;
+
+ assert(Z->touched != NULL);
+
+ /* beware, split might change Z */
+ N = Z->touched_next;
+
+ /* remove it from the touched set */
+ Z->on_touched = 0;
+
+ /* Empty local Z.touched. */
+ for (e = touched; e != NULL; e = e->next) {
+ assert(e->is_follower == 0);
+ e->on_touched = 0;
+ }
+ Z->touched = NULL;
+ Z->n_touched = 0;
+
+ if (0 < n_touched && n_touched < Z->n_leader) {
+ DB((dbg, LEVEL_2, "Split part%d by touched\n", Z->nr));
+ split(&Z, touched, env);
+ } else
+ assert(n_touched <= Z->n_leader);
+ }
+ }
+} /* cause_splits */
+
+/**
+ * Implements split_by_what(): Split a partition by characteristics given
+ * by the what function.
+ *
+ * @param X the partition to split
+ * @param What a function returning an Id for every node of the partition X
+ * @param P a list to store the result partitions
+ * @param env the environment
+ *
+ * @return *P
+ */
+static partition_t *split_by_what(partition_t *X, what_func What,
+ partition_t **P, environment_t *env) {
+ node_t *x, *S;
+ listmap_t map;
+ listmap_entry_t *iter;
+ partition_t *R;
+
+ /* Let map be an empty mapping from the range of What to (local) list of Nodes. */
+ listmap_init(&map);
+ list_for_each_entry(node_t, x, &X->Leader, node_list) {
+ void *id = What(x, env);
+ listmap_entry_t *entry;
+
+ if (id == NULL) {
+ /* input not allowed, ignore */
+ continue;
+ }
+ /* Add x to map[What(x)]. */
+ entry = listmap_find(&map, id);
+ x->next = entry->list;
+ entry->list = x;
+ }
+ /* Let P be a set of Partitions. */
+
+ /* for all sets S except one in the range of map do */
+ for (iter = map.values; iter != NULL; iter = iter->next) {
+ if (iter->next == NULL) {
+ /* this is the last entry, ignore */
+ break;
+ }
+ S = iter->list;
+
+ /* Add SPLIT( X, S ) to P. */
+ DB((dbg, LEVEL_2, "Split part%d by what\n", X->nr));
+ R = split(&X, S, env);
+ R->split_next = *P;
+ *P = R;
+ }
+ /* Add X to P. */
+ X->split_next = *P;
+ *P = X;
+
+ listmap_term(&map);
+ return *P;
+} /* split_by_what */
+
+/** lambda n.(n.type) */
+static void *lambda_type(const node_t *node, environment_t *env) {
+ (void)env;
+ return node->type.tv;
+} /* lambda_type */
+
+/** lambda n.(n.opcode) */
+static void *lambda_opcode(const node_t *node, environment_t *env) {
+ opcode_key_t key, *entry;
+ ir_node *irn = node->node;
+
+ key.code = get_irn_opcode(irn);
+ key.mode = get_irn_mode(irn);
+ key.arity = get_irn_arity(irn);
+ key.u.proj = 0;
+ key.u.ent = NULL;
+
+ switch (get_irn_opcode(irn)) {
+ case iro_Proj:
+ key.u.proj = get_Proj_proj(irn);
+ break;
+ case iro_Sel:
+ key.u.ent = get_Sel_entity(irn);
+ break;
+ default:
+ break;
+ }
+
+ entry = set_insert(env->opcode2id_map, &key, sizeof(key), opcode_hash(&key));
+ return entry;
+} /* lambda_opcode */
+
+/** lambda n.(n[i].partition) */
+static void *lambda_partition(const node_t *node, environment_t *env) {
+ ir_node *skipped = skip_Proj(node->node);
+ ir_node *pred;
+ node_t *p;
+ int i = env->lambda_input;
+
+ if (i >= get_irn_arity(node->node)) {
+ /* we are outside the allowed range */
+ return NULL;
+ }
+
+ /* ignore the "control input" for non-pinned nodes
+ if we are running in GCSE mode */
+ if (i < env->end_idx && get_irn_pinned(skipped) != op_pin_state_pinned)
+ return NULL;
+
+ pred = i == -1 ? get_irn_n(skipped, i) : get_irn_n(node->node, i);
+ p = get_irn_node(pred);
+
+ return p->part;
+} /* lambda_partition */
+
+/**
+ * Returns true if a type is a constant.
+ */
+static int is_con(const lattice_elem_t type) {
+ /* be conservative */
+ if (is_tarval(type.tv))
+ return tarval_is_constant(type.tv);
+ return is_entity(type.sym.entity_p);
+} /* is_con */
+
+/**
+ * Implements split_by().
+ *
+ * @param X the partition to split
+ * @param env the environment
+ */
+static void split_by(partition_t *X, environment_t *env) {
+ partition_t *I, *P = NULL;
+ int input;
+
+ dump_partition("split_by", X);
+
+ if (X->n_leader == 1) {
+ /* we have only one leader, no need to split, just check it's type */
+ node_t *x = get_first_node(X);
+ X->type_is_T_or_C = x->type.tv == tarval_top || is_con(x->type);
+ return;
+ }
+
+ DB((dbg, LEVEL_2, "WHAT = lambda n.(n.type) on part%d\n", X->nr));
+ P = split_by_what(X, lambda_type, &P, env);
+
+ /* adjust the type tags, we have split partitions by type */
+ for (I = P; I != NULL; I = I->split_next) {
+ node_t *x = get_first_node(I);
+ I->type_is_T_or_C = x->type.tv == tarval_top || is_con(x->type);
+ }
+
+ do {
+ partition_t *Y = P;
+
+ P = P->split_next;
+ if (Y->n_leader > 1) {
+ /* we do not want split the TOP or constant partitions */
+ if (! Y->type_is_T_or_C) {
+ partition_t *Q = NULL;
+
+ DB((dbg, LEVEL_2, "WHAT = lambda n.(n.opcode) on part%d\n", Y->nr));
+ Q = split_by_what(Y, lambda_opcode, &Q, env);
+
+ do {
+ partition_t *Z = Q;
+
+ Q = Q->split_next;
+ if (Z->n_leader > 1) {
+ const node_t *first = get_first_node(Z);
+ int arity = get_irn_arity(first->node);
+ partition_t *R, *S;
+
+ /*
+ * BEWARE: during splitting by input 2 for instance we might
+ * create new partitions which are different by input 1, so collect
+ * them and split further.
+ */
+ Z->split_next = NULL;
+ R = Z;
+ S = NULL;
+ for (input = arity - 1; input >= -1; --input) {
+ do {
+ partition_t *Z_prime = R;
+
+ R = R->split_next;
+ if (Z_prime->n_leader > 1) {
+ env->lambda_input = input;
+ DB((dbg, LEVEL_2, "WHAT = lambda n.(n[%d].partition) on part%d\n", input, Z_prime->nr));
+ S = split_by_what(Z_prime, lambda_partition, &S, env);
+ } else {
+ Z_prime->split_next = S;
+ S = Z_prime;
+ }
+ } while (R != NULL);
+ R = S;
+ S = NULL;
+ }
+ }
+ } while (Q != NULL);
+ }
+ }
+ } while (P != NULL);
+} /* split_by */
+
+/**
+ * (Re-)compute the type for a given node.
+ *
+ * @param node the node
+ */
+static void default_compute(node_t *node) {
+ int i;
+ ir_node *irn = node->node;
+ node_t *block = get_irn_node(get_nodes_block(irn));
+
+ if (block->type.tv == tarval_unreachable) {
+ node->type.tv = tarval_top;
+ return;
+ }
+
+ /* if any of the data inputs have type top, the result is type top */
+ for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_n(irn, i);
+ node_t *p = get_irn_node(pred);
+
+ if (p->type.tv == tarval_top) {
+ node->type.tv = tarval_top;
+ return;
+ }
+ }
+
+ if (get_irn_mode(node->node) == mode_X)
+ node->type.tv = tarval_reachable;
+ else
+ node->type.tv = computed_value(irn);
+} /* default_compute */
+
+/**
+ * (Re-)compute the type for a Block node.
+ *
+ * @param node the node
+ */
+static void compute_Block(node_t *node) {
+ int i;
+ ir_node *block = node->node;
+
+ if (block == get_irg_start_block(current_ir_graph)) {
+ /* start block is always reachable */
+ node->type.tv = tarval_reachable;
+ return;
+ }
+
+ for (i = get_Block_n_cfgpreds(block) - 1; i >= 0; --i) {
+ node_t *pred = get_irn_node(get_Block_cfgpred(block, i));
+
+ if (pred->type.tv == tarval_reachable) {
+ /* A block is reachable, if at least of predecessor is reachable. */
+ node->type.tv = tarval_reachable;
+ return;
+ }
+ }
+ node->type.tv = tarval_top;
+} /* compute_Block */
+
+/**
+ * (Re-)compute the type for a Bad node.
+ *
+ * @param node the node
+ */
+static void compute_Bad(node_t *node) {
+ /* Bad nodes ALWAYS compute Top */
+ node->type.tv = tarval_top;
+} /* compute_Bad */
+
+/**
+ * (Re-)compute the type for an Unknown node.
+ *
+ * @param node the node
+ */
+static void compute_Unknown(node_t *node) {
+ /* While Unknown nodes should compute Top this is dangerous:
+ * a Top input to a Cond would lead to BOTH control flows unreachable.
+ * While this is correct in the given semantics, it would destroy the Firm
+ * graph.
+ *
+ * It would be safe to compute Top IF it can be assured, that only Cmp
+ * nodes are inputs to Conds. We check that first.
+ * This is the way Frontends typically build Firm, but some optimizations
+ * (cond_eval for instance) might replace them by Phib's...
+ */
+ node->type.tv = tarval_UNKNOWN;
+} /* compute_Unknown */
+
+/**
+ * (Re-)compute the type for a Jmp node.
+ *
+ * @param node the node
+ */
+static void compute_Jmp(node_t *node) {
+ node_t *block = get_irn_node(get_nodes_block(node->node));
+
+ node->type = block->type;
+} /* compute_Jmp */
+
+/**
+ * (Re-)compute the type for the End node.
+ *
+ * @param node the node
+ */
+static void compute_End(node_t *node) {
+ /* the End node is NOT dead of course */
+ node->type.tv = tarval_reachable;
+}
+
+/**
+ * (Re-)compute the type for a SymConst node.
+ *
+ * @param node the node
+ */
+static void compute_SymConst(node_t *node) {
+ ir_node *irn = node->node;
+ node_t *block = get_irn_node(get_nodes_block(irn));
+
+ if (block->type.tv == tarval_unreachable) {
+ node->type.tv = tarval_top;
+ return;
+ }
+ switch (get_SymConst_kind(irn)) {
+ case symconst_addr_ent:
+ /* case symconst_addr_name: cannot handle this yet */
+ node->type.sym = get_SymConst_symbol(irn);
+ break;
+ default:
+ node->type.tv = computed_value(irn);
+ }
+} /* compute_SymConst */
+
+/**
+ * (Re-)compute the type for a Phi node.
+ *
+ * @param node the node
+ */
+static void compute_Phi(node_t *node) {
+ int i;
+ ir_node *phi = node->node;
+ lattice_elem_t type;
+
+ /* if a Phi is in a unreachable block, its type is TOP */
+ node_t *block = get_irn_node(get_nodes_block(phi));
+
+ if (block->type.tv == tarval_unreachable) {
+ node->type.tv = tarval_top;
+ return;
+ }
+
+ /* Phi implements the Meet operation */
+ type.tv = tarval_top;
+ for (i = get_Phi_n_preds(phi) - 1; i >= 0; --i) {
+ node_t *pred = get_irn_node(get_Phi_pred(phi, i));
+ node_t *pred_X = get_irn_node(get_Block_cfgpred(block->node, i));
+
+ if (pred_X->type.tv == tarval_unreachable || pred->type.tv == tarval_top) {
+ /* ignore TOP inputs: We must check here for unreachable blocks,
+ because Firm constants live in the Start Block are NEVER Top.
+ Else, a Phi (1,2) will produce Bottom, even if the 2 for instance
+ comes from a unreachable input. */
+ continue;
+ }
+ if (pred->type.tv == tarval_bottom) {
+ node->type.tv = tarval_bottom;
+ return;
+ } else if (type.tv == tarval_top) {
+ /* first constant found */
+ type = pred->type;
+ } else if (type.tv != pred->type.tv) {
+ /* different constants or tarval_bottom */
+ node->type.tv = tarval_bottom;
+ return;
+ }
+ /* else nothing, constants are the same */
+ }
+ node->type = type;
+} /* compute_Phi */
+
+/**
+ * (Re-)compute the type for an Add. Special case: one nodes is a Zero Const.
+ *
+ * @param node the node
+ */
+static void compute_Add(node_t *node) {
+ ir_node *sub = node->node;
+ node_t *l = get_irn_node(get_Add_left(sub));
+ node_t *r = get_irn_node(get_Add_right(sub));
+ lattice_elem_t a = l->type;
+ lattice_elem_t b = r->type;
+ ir_mode *mode;
+
+ if (a.tv == tarval_top || b.tv == tarval_top) {
+ node->type.tv = tarval_top;
+ } else if (a.tv == tarval_bottom || b.tv == tarval_bottom) {
+ node->type.tv = tarval_bottom;
+ } else {
+ /* x + 0 = 0 + x = x, but beware of floating point +0 + -0, so we
+ must call tarval_add() first to handle this case! */
+ if (is_tarval(a.tv)) {
+ if (is_tarval(b.tv)) {
+ node->type.tv = tarval_add(a.tv, b.tv);
+ return;
+ }
+ mode = get_tarval_mode(a.tv);
+ if (a.tv == get_mode_null(mode)) {
+ node->type = b;
+ return;
+ }
+ } else if (is_tarval(b.tv)) {
+ mode = get_tarval_mode(b.tv);
+ if (b.tv == get_mode_null(mode)) {
+ node->type = a;
+ return;
+ }
+ }
+ node->type.tv = tarval_bottom;
+ }
+} /* compute_Add */
+
+/**
+ * (Re-)compute the type for a Sub. Special case: both nodes are congruent.
+ *
+ * @param node the node
+ */
+static void compute_Sub(node_t *node) {
+ ir_node *sub = node->node;
+ node_t *l = get_irn_node(get_Sub_left(sub));
+ node_t *r = get_irn_node(get_Sub_right(sub));
+ lattice_elem_t a = l->type;
+ lattice_elem_t b = r->type;
+ tarval *tv;
+
+ if (a.tv == tarval_top || b.tv == tarval_top) {
+ node->type.tv = tarval_top;
+ } else if (is_con(a) && is_con(b)) {
+ if (is_tarval(a.tv) && is_tarval(b.tv)) {
+ node->type.tv = tarval_sub(a.tv, b.tv, get_irn_mode(sub));
+ } else if (is_tarval(a.tv) && tarval_is_null(a.tv)) {
+ node->type = b;
+ } else if (is_tarval(b.tv) && tarval_is_null(b.tv)) {
+ node->type = a;
+ } else {
+ node->type.tv = tarval_bottom;
+ }
+ node->by_all_const = 1;
+ } else if (r->part == l->part &&
+ (!mode_is_float(get_irn_mode(l->node)))) {
+ /*
+ * BEWARE: a - a is NOT always 0 for floating Point values, as
+ * NaN op NaN = NaN, so we must check this here.
+ */
+ ir_mode *mode = get_irn_mode(sub);
+ tv = get_mode_null(mode);
+
+ /* if the node was ONCE evaluated by all constants, but now
+ this breakes AND we cat by partition a different result, switch to bottom.
+ This happens because initially all nodes are in the same partition ... */
+ if (node->by_all_const && node->type.tv != tv)
+ tv = tarval_bottom;
+ node->type.tv = tv;
+ } else {
+ node->type.tv = tarval_bottom;
+ }
+} /* compute_Sub */
+
+/**
+ * (Re-)compute the type for an Eor. Special case: both nodes are congruent.
+ *
+ * @param node the node
+ */
+static void compute_Eor(node_t *node) {
+ ir_node *eor = node->node;
+ node_t *l = get_irn_node(get_Eor_left(eor));
+ node_t *r = get_irn_node(get_Eor_right(eor));
+ lattice_elem_t a = l->type;
+ lattice_elem_t b = r->type;
+ tarval *tv;
+
+ if (a.tv == tarval_top || b.tv == tarval_top) {
+ node->type.tv = tarval_top;
+ } else if (is_con(a) && is_con(b)) {
+ if (is_tarval(a.tv) && is_tarval(b.tv)) {
+ node->type.tv = tarval_eor(a.tv, b.tv);
+ } else if (is_tarval(a.tv) && tarval_is_null(a.tv)) {
+ node->type = b;
+ } else if (is_tarval(b.tv) && tarval_is_null(b.tv)) {
+ node->type = a;
+ } else {
+ node->type.tv = tarval_bottom;
+ }
+ node->by_all_const = 1;
+ } else if (r->part == l->part) {
+ ir_mode *mode = get_irn_mode(eor);
+ tv = get_mode_null(mode);
+
+ /* if the node was ONCE evaluated by all constants, but now
+ this breakes AND we cat by partition a different result, switch to bottom.
+ This happens because initially all nodes are in the same partition ... */
+ if (node->by_all_const && node->type.tv != tv)
+ tv = tarval_bottom;
+ node->type.tv = tv;
+ } else {
+ node->type.tv = tarval_bottom;
+ }
+} /* compute_Eor */
+
+/**
+ * (Re-)compute the type for Cmp.
+ *
+ * @param node the node
+ */
+static void compute_Cmp(node_t *node) {
+ ir_node *cmp = node->node;
+ node_t *l = get_irn_node(get_Cmp_left(cmp));
+ node_t *r = get_irn_node(get_Cmp_right(cmp));
+ lattice_elem_t a = l->type;
+ lattice_elem_t b = r->type;
+
+ if (a.tv == tarval_top || b.tv == tarval_top) {
+#ifdef WITH_UNKNOWN
+ /*
+ * Top is congruent to any other value, we can
+ * calculate the compare result.
+ */
+ node->type.tv = tarval_b_true;
+#else
+ node->type.tv = tarval_top;
+#endif
+ } else if (is_con(a) && is_con(b)) {
+ /* both nodes are constants, we can probably do something */
+ node->type.tv = tarval_b_true;
+ } else if (r->part == l->part) {
+ /* both nodes congruent, we can probably do something */
+ node->type.tv = tarval_b_true;
+ } else {
+ node->type.tv = tarval_bottom;
+ }
+} /* compute_Proj_Cmp */
+
+/**
+ * (Re-)compute the type for a Proj(Cmp).
+ *
+ * @param node the node
+ * @param cond the predecessor Cmp node
+ */
+static void compute_Proj_Cmp(node_t *node, ir_node *cmp) {
+ ir_node *proj = node->node;
+ node_t *l = get_irn_node(get_Cmp_left(cmp));
+ node_t *r = get_irn_node(get_Cmp_right(cmp));
+ lattice_elem_t a = l->type;
+ lattice_elem_t b = r->type;
+ pn_Cmp pnc = get_Proj_proj(proj);
+ tarval *tv;
+
+ if (a.tv == tarval_top || b.tv == tarval_top) {
+#ifdef WITH_UNKNOWN
+ /* see above */
+ tv = new_tarval_from_long((pnc & pn_Cmp_Eq) ^ pn_Cmp_Eq, mode_b);
+ goto not_equal;
+#else
+ node->type.tv = tarval_top;
+#endif
+ } else if (is_con(a) && is_con(b)) {
+ default_compute(node);
+ node->by_all_const = 1;
+ } else if (r->part == l->part &&
+ (!mode_is_float(get_irn_mode(l->node)) || pnc == pn_Cmp_Lt || pnc == pn_Cmp_Gt)) {
+ /*
+ * BEWARE: a == a is NOT always True for floating Point values, as
+ * NaN != NaN is defined, so we must check this here.
+ */
+ tv = new_tarval_from_long(pnc & pn_Cmp_Eq, mode_b);
+#ifdef WITH_UNKNOWN
+not_equal:
+#endif
+
+ /* if the node was ONCE evaluated by all constants, but now
+ this breakes AND we cat by partition a different result, switch to bottom.
+ This happens because initially all nodes are in the same partition ... */
+ if (node->by_all_const && node->type.tv != tv)
+ tv = tarval_bottom;
+ node->type.tv = tv;
+ } else {
+ node->type.tv = tarval_bottom;
+ }
+} /* compute_Proj_Cmp */
+
+/**
+ * (Re-)compute the type for a Proj(Cond).
+ *
+ * @param node the node
+ * @param cond the predecessor Cond node
+ */
+static void compute_Proj_Cond(node_t *node, ir_node *cond) {
+ ir_node *proj = node->node;
+ long pnc = get_Proj_proj(proj);
+ ir_node *sel = get_Cond_selector(cond);
+ node_t *selector = get_irn_node(sel);
+
+ if (get_irn_mode(sel) == mode_b) {
+ /* an IF */
+ if (pnc == pn_Cond_true) {
+ if (selector->type.tv == tarval_b_false) {
+ node->type.tv = tarval_unreachable;
+ } else if (selector->type.tv == tarval_b_true) {
+ node->type.tv = tarval_reachable;
+ } else if (selector->type.tv == tarval_bottom) {
+ node->type.tv = tarval_reachable;
+ } else {
+ assert(selector->type.tv == tarval_top);
+ node->type.tv = tarval_unreachable;
+ }
+ } else {
+ assert(pnc == pn_Cond_false);
+
+ if (selector->type.tv == tarval_b_false) {
+ node->type.tv = tarval_reachable;
+ } else if (selector->type.tv == tarval_b_true) {
+ node->type.tv = tarval_unreachable;
+ } else if (selector->type.tv == tarval_bottom) {
+ node->type.tv = tarval_reachable;
+ } else {
+ assert(selector->type.tv == tarval_top);
+ node->type.tv = tarval_unreachable;
+ }
+ }
+ } else {
+ /* an SWITCH */
+ if (selector->type.tv == tarval_bottom) {
+ node->type.tv = tarval_reachable;
+ } else if (selector->type.tv == tarval_top) {
+ node->type.tv = tarval_unreachable;
+ } else {
+ long value = get_tarval_long(selector->type.tv);
+ if (pnc == get_Cond_defaultProj(cond)) {
+ /* default switch, have to check ALL other cases */
+ int i;
+
+ for (i = get_irn_n_outs(cond) - 1; i >= 0; --i) {
+ ir_node *succ = get_irn_out(cond, i);
+
+ if (succ == proj)
+ continue;
+ if (value == get_Proj_proj(succ)) {
+ /* we found a match, will NOT take the default case */
+ node->type.tv = tarval_unreachable;
+ return;
+ }
+ }
+ /* all cases checked, no match, will take default case */
+ node->type.tv = tarval_reachable;
+ } else {
+ /* normal case */
+ node->type.tv = value == pnc ? tarval_reachable : tarval_unreachable;
+ }
+ }
+ }
+} /* compute_Proj_Cond */
+
+/**
+ * (Re-)compute the type for a Proj-Node.
+ *
+ * @param node the node
+ */
+static void compute_Proj(node_t *node) {
+ ir_node *proj = node->node;
+ ir_mode *mode = get_irn_mode(proj);
+ node_t *block = get_irn_node(get_nodes_block(skip_Proj(proj)));
+ ir_node *pred = get_Proj_pred(proj);
+
+ if (block->type.tv == tarval_unreachable) {
+ /* a Proj in a unreachable Block stay Top */
+ node->type.tv = tarval_top;
+ return;
+ }
+ if (get_irn_node(pred)->type.tv == tarval_top) {
+ /* if the predecessor is Top, its Proj follow */
+ node->type.tv = tarval_top;
+ return;
+ }
+
+ if (mode == mode_M) {
+ /* mode M is always bottom */
+ node->type.tv = tarval_bottom;
+ return;
+ }
+ if (mode != mode_X) {
+ if (is_Cmp(pred))
+ compute_Proj_Cmp(node, pred);
+ else
+ default_compute(node);
+ return;
+ }
+ /* handle mode_X nodes */
+
+ switch (get_irn_opcode(pred)) {
+ case iro_Start:
+ /* the Proj_X from the Start is always reachable.
+ However this is already handled at the top. */
+ node->type.tv = tarval_reachable;
+ break;
+ case iro_Cond:
+ compute_Proj_Cond(node, pred);
+ break;
+ default:
+ default_compute(node);
+ }
+} /* compute_Proj */
+
+/**
+ * (Re-)compute the type for a Confirm.
+ *
+ * @param node the node
+ */
+static void compute_Confirm(node_t *node) {
+ ir_node *confirm = node->node;
+ node_t *pred = get_irn_node(get_Confirm_value(confirm));
+
+ if (get_Confirm_cmp(confirm) == pn_Cmp_Eq) {
+ node_t *bound = get_irn_node(get_Confirm_bound(confirm));
+
+ if (is_con(bound->type)) {
+ /* is equal to a constant */
+ node->type = bound->type;
+ return;
+ }
+ }
+ /* a Confirm is a copy OR a Const */
+ node->type = pred->type;
+} /* compute_Confirm */
+
+/**
+ * (Re-)compute the type for a Max.
+ *
+ * @param node the node
+ */
+static void compute_Max(node_t *node) {
+ ir_node *op = node->node;
+ node_t *l = get_irn_node(get_binop_left(op));
+ node_t *r = get_irn_node(get_binop_right(op));
+ lattice_elem_t a = l->type;
+ lattice_elem_t b = r->type;
+
+ if (a.tv == tarval_top || b.tv == tarval_top) {
+ node->type.tv = tarval_top;
+ } else if (is_con(a) && is_con(b)) {
+ /* both nodes are constants, we can probably do something */
+ if (a.tv == b.tv) {
+ /* this case handles symconsts as well */
+ node->type = a;
+ } else {
+ ir_mode *mode = get_irn_mode(op);
+ tarval *tv_min = get_mode_min(mode);
+
+ if (a.tv == tv_min)
+ node->type = b;
+ else if (b.tv == tv_min)
+ node->type = a;
+ else if (is_tarval(a.tv) && is_tarval(b.tv)) {
+ if (tarval_cmp(a.tv, b.tv) & pn_Cmp_Gt)
+ node->type.tv = a.tv;
+ else
+ node->type.tv = b.tv;
+ } else {
+ node->type.tv = tarval_bad;
+ }
+ }
+ } else if (r->part == l->part) {
+ /* both nodes congruent, we can probably do something */
+ node->type = a;
+ } else {
+ node->type.tv = tarval_bottom;
+ }
+} /* compute_Max */
+
+/**
+ * (Re-)compute the type for a Min.
+ *
+ * @param node the node
+ */
+static void compute_Min(node_t *node) {
+ ir_node *op = node->node;
+ node_t *l = get_irn_node(get_binop_left(op));
+ node_t *r = get_irn_node(get_binop_right(op));
+ lattice_elem_t a = l->type;
+ lattice_elem_t b = r->type;
+
+ if (a.tv == tarval_top || b.tv == tarval_top) {
+ node->type.tv = tarval_top;
+ } else if (is_con(a) && is_con(b)) {
+ /* both nodes are constants, we can probably do something */
+ if (a.tv == b.tv) {
+ /* this case handles symconsts as well */
+ node->type = a;
+ } else {
+ ir_mode *mode = get_irn_mode(op);
+ tarval *tv_max = get_mode_max(mode);
+
+ if (a.tv == tv_max)
+ node->type = b;
+ else if (b.tv == tv_max)
+ node->type = a;
+ else if (is_tarval(a.tv) && is_tarval(b.tv)) {
+ if (tarval_cmp(a.tv, b.tv) & pn_Cmp_Gt)
+ node->type.tv = a.tv;
+ else
+ node->type.tv = b.tv;
+ } else {
+ node->type.tv = tarval_bad;
+ }
+ }
+ } else if (r->part == l->part) {
+ /* both nodes congruent, we can probably do something */
+ node->type = a;
+ } else {
+ node->type.tv = tarval_bottom;
+ }
+} /* compute_Min */
+
+/**
+ * (Re-)compute the type for a given node.
+ *
+ * @param node the node
+ */
+static void compute(node_t *node) {
+ compute_func func;
+
+ if (is_no_Block(node->node)) {
+ node_t *block = get_irn_node(get_nodes_block(node->node));
+
+ if (block->type.tv == tarval_unreachable) {
+ node->type.tv = tarval_top;
+ return;
+ }
+ }
+
+ func = (compute_func)node->node->op->ops.generic;
+ if (func != NULL)
+ func(node);
+} /* compute */
+
+/*
+ * Identity functions: Note that one might thing that identity() is just a
+ * synonym for equivalent_node(). While this is true, we cannot use it for the algorithm
+ * here, because it expects that the identity node is one of the inputs, which is NOT
+ * always true for equivalent_node() which can handle (and does sometimes) DAGs.
+ * So, we have our own implementation, which copies some parts of equivalent_node()
+ */
+
+/**
+ * Calculates the Identity for Phi nodes
+ */
+static node_t *identity_Phi(node_t *node) {
+ ir_node *phi = node->node;
+ ir_node *block = get_nodes_block(phi);
+ node_t *n_part = NULL;
+ int i;
+
+ for (i = get_Phi_n_preds(phi) - 1; i >= 0; --i) {
+ node_t *pred_X = get_irn_node(get_Block_cfgpred(block, i));
+
+ if (pred_X->type.tv == tarval_reachable) {
+ node_t *pred = get_irn_node(get_Phi_pred(phi, i));
+
+ if (n_part == NULL)
+ n_part = pred;
+ else if (n_part->part != pred->part) {
+ /* incongruent inputs, not a follower */
+ return node;
+ }
+ }
+ }
+ /* if n_part is NULL here, all inputs path are dead, the Phi computes
+ * tarval_top, is in the TOP partition and should NOT being split! */
+ assert(n_part != NULL);
+ return n_part;
+} /* identity_Phi */
+
+/**
+ * Calculates the Identity for commutative 0 neutral nodes.
+ */
+static node_t *identity_comm_zero_binop(node_t *node) {
+ ir_node *op = node->node;
+ node_t *a = get_irn_node(get_binop_left(op));
+ node_t *b = get_irn_node(get_binop_right(op));
+ ir_mode *mode = get_irn_mode(op);
+ tarval *zero;
+
+ /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */
+ if (mode_is_float(mode) && (get_irg_fp_model(current_ir_graph) & fp_strict_algebraic))
+ return node;
+
+ /* node: no input should be tarval_top, else the binop would be also
+ * Top and not being split. */
+ zero = get_mode_null(mode);
+ if (a->type.tv == zero)
+ return b;
+ if (b->type.tv == zero)
+ return a;
+ return node;
+} /* identity_comm_zero_binop */
+
+/**
+ * Calculates the Identity for Shift nodes.
+ */
+static node_t *identity_shift(node_t *node) {
+ ir_node *op = node->node;
+ node_t *b = get_irn_node(get_binop_right(op));
+ ir_mode *mode = get_irn_mode(b->node);
+ tarval *zero;
+
+ /* node: no input should be tarval_top, else the binop would be also
+ * Top and not being split. */
+ zero = get_mode_null(mode);
+ if (b->type.tv == zero)
+ return get_irn_node(get_binop_left(op));
+ return node;
+} /* identity_shift */
+
+/**
+ * Calculates the Identity for Mul nodes.
+ */
+static node_t *identity_Mul(node_t *node) {
+ ir_node *op = node->node;
+ node_t *a = get_irn_node(get_Mul_left(op));
+ node_t *b = get_irn_node(get_Mul_right(op));
+ ir_mode *mode = get_irn_mode(op);
+ tarval *one;
+
+ /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */
+ if (mode_is_float(mode) && (get_irg_fp_model(current_ir_graph) & fp_strict_algebraic))
+ return node;
+
+ /* node: no input should be tarval_top, else the binop would be also
+ * Top and not being split. */
+ one = get_mode_one(mode);
+ if (a->type.tv == one)
+ return b;
+ if (b->type.tv == one)
+ return a;
+ return node;
+} /* identity_Mul */
+
+/**
+ * Calculates the Identity for Sub nodes.
+ */
+static node_t *identity_Sub(node_t *node) {
+ ir_node *sub = node->node;
+ node_t *b = get_irn_node(get_Sub_right(sub));
+ ir_mode *mode = get_irn_mode(sub);
+
+ /* for FP these optimizations are only allowed if fp_strict_algebraic is disabled */
+ if (mode_is_float(mode) && (get_irg_fp_model(current_ir_graph) & fp_strict_algebraic))
+ return node;
+
+ /* node: no input should be tarval_top, else the binop would be also
+ * Top and not being split. */
+ if (b->type.tv == get_mode_null(mode))
+ return get_irn_node(get_Sub_left(sub));
+ return node;
+} /* identity_Mul */
+
+/**
+ * Calculates the Identity for And nodes.
+ */
+static node_t *identity_And(node_t *node) {
+ ir_node *and = node->node;
+ node_t *a = get_irn_node(get_And_left(and));
+ node_t *b = get_irn_node(get_And_right(and));
+ tarval *neutral = get_mode_all_one(get_irn_mode(and));
+
+ /* node: no input should be tarval_top, else the And would be also
+ * Top and not being split. */
+ if (a->type.tv == neutral)
+ return b;
+ if (b->type.tv == neutral)
+ return a;
+ return node;
+} /* identity_And */
+
+/**
+ * Calculates the Identity for Confirm nodes.
+ */
+static node_t *identity_Confirm(node_t *node) {
+ ir_node *confirm = node->node;
+
+ /* a Confirm is always a Copy */
+ return get_irn_node(get_Confirm_value(confirm));
+} /* identity_Confirm */
+
+/**
+ * Calculates the Identity for Mux nodes.
+ */
+static node_t *identity_Mux(node_t *node) {
+ ir_node *mux = node->node;
+ node_t *t = get_irn_node(get_Mux_true(mux));
+ node_t *f = get_irn_node(get_Mux_false(mux));
+ /*node_t *sel; */
+
+ if (t->part == f->part)
+ return t;
+
+ /* for now, the 1-input identity is not supported */
+#if 0
+ sel = get_irn_node(get_Mux_sel(mux));
+
+ /* Mux sel input is mode_b, so it is always a tarval */
+ if (sel->type.tv == tarval_b_true)
+ return t;
+ if (sel->type.tv == tarval_b_false)
+ return f;
+#endif
+ return node;
+} /* identity_Mux */
+
+/**
+ * Calculates the Identity for Min nodes.
+ */
+static node_t *identity_Min(node_t *node) {
+ ir_node *op = node->node;
+ node_t *a = get_irn_node(get_binop_left(op));
+ node_t *b = get_irn_node(get_binop_right(op));
+ ir_mode *mode = get_irn_mode(op);
+ tarval *tv_max;
+
+ if (a->part == b->part) {
+ /* leader of multiple predecessors */
+ return a;
+ }
+
+ /* works even with NaN */
+ tv_max = get_mode_max(mode);
+ if (a->type.tv == tv_max)
+ return b;
+ if (b->type.tv == tv_max)
+ return a;
+ return node;
+} /* identity_Min */
+
+/**
+ * Calculates the Identity for Max nodes.
+ */
+static node_t *identity_Max(node_t *node) {
+ ir_node *op = node->node;
+ node_t *a = get_irn_node(get_binop_left(op));
+ node_t *b = get_irn_node(get_binop_right(op));
+ ir_mode *mode = get_irn_mode(op);
+ tarval *tv_min;
+
+ if (a->part == b->part) {
+ /* leader of multiple predecessors */
+ return a;
+ }
+
+ /* works even with NaN */
+ tv_min = get_mode_min(mode);
+ if (a->type.tv == tv_min)
+ return b;
+ if (b->type.tv == tv_min)
+ return a;
+ return node;
+} /* identity_Max */
+
+/**
+ * Calculates the Identity for nodes.
+ */
+static node_t *identity(node_t *node) {
+ ir_node *irn = node->node;
+
+ switch (get_irn_opcode(irn)) {
+ case iro_Phi:
+ return identity_Phi(node);
+ case iro_Mul:
+ return identity_Mul(node);
+ case iro_Add:
+ case iro_Or:
+ case iro_Eor:
+ return identity_comm_zero_binop(node);
+ case iro_Shr:
+ case iro_Shl:
+ case iro_Shrs:
+ case iro_Rotl:
+ return identity_shift(node);
+ case iro_And:
+ return identity_And(node);
+ case iro_Sub:
+ return identity_Sub(node);
+ case iro_Confirm:
+ return identity_Confirm(node);
+ case iro_Mux:
+ return identity_Mux(node);
+ case iro_Min:
+ return identity_Min(node);
+ case iro_Max:
+ return identity_Max(node);
+ default:
+ return node;
+ }
+} /* identity */
+
+/**
+ * Node follower is a (new) follower of leader, segregate Leader
+ * out edges.
+ */
+static void segregate_def_use_chain_1(const ir_node *follower, node_t *leader) {
+ ir_node *l = leader->node;
+ int j, i, n = get_irn_n_outs(l);
+
+ DB((dbg, LEVEL_2, "%+F is a follower of %+F\n", follower, leader->node));
+ /* The leader edges must remain sorted, but follower edges can
+ be unsorted. */
+ for (i = leader->n_followers + 1; i <= n; ++i) {
+ if (l->out[i].use == follower) {
+ ir_def_use_edge t = l->out[i];
+
+ for (j = i - 1; j >= leader->n_followers + 1; --j)
+ l->out[j + 1] = l->out[j];
+ ++leader->n_followers;
+ l->out[leader->n_followers] = t;
+ break;
+ }
+ }
+} /* segregate_def_use_chain_1 */
+
+/**
+ * Node follower is a (new) follower of leader, segregate Leader
+ * out edges. If follower is a n-congruent Input identity, all follower
+ * inputs congruent to follower are also leader.
+ *
+ * @param follower the follower IR node
+ */
+static void segregate_def_use_chain(const ir_node *follower) {
+ int i;
+
+ for (i = get_irn_arity(follower) - 1; i >= 0; --i) {
+ node_t *pred = get_irn_node(get_irn_n(follower, i));
+
+ segregate_def_use_chain_1(follower, pred);
+ }
+} /* segregate_def_use_chain */
+
+/**
+ * Propagate constant evaluation.
+ *
+ * @param env the environment
+ */
+static void propagate(environment_t *env) {
+ partition_t *X, *Y;
+ node_t *x;
+ lattice_elem_t old_type;
+ node_t *fallen;
+ unsigned n_fallen, old_type_was_T_or_C;
+ int i;
+
+ while (env->cprop != NULL) {
+ void *oldopcode = NULL;
+
+ /* remove the first partition X from cprop */
+ X = env->cprop;
+ X->on_cprop = 0;
+ env->cprop = X->cprop_next;
+
+ old_type_was_T_or_C = X->type_is_T_or_C;
+
+ DB((dbg, LEVEL_2, "Propagate type on part%d\n", X->nr));
+ fallen = NULL;
+ n_fallen = 0;
+ while (! list_empty(&X->cprop)) {
+ /* remove the first Node x from X.cprop */
+ x = list_entry(X->cprop.next, node_t, cprop_list);
+ //assert(x->part == X);
+ list_del(&x->cprop_list);
+ x->on_cprop = 0;
+
+ if (x->is_follower && identity(x) == x) {
+ /* check the opcode first */
+ if (oldopcode == NULL) {
+ oldopcode = lambda_opcode(get_first_node(X), env);
+ }
+ if (oldopcode != lambda_opcode(x, env)) {
+ if (x->on_fallen == 0) {
+ /* different opcode -> x falls out of this partition */
+ x->next = fallen;
+ x->on_fallen = 1;
+ fallen = x;
+ ++n_fallen;
+ DB((dbg, LEVEL_2, "Add node %+F to fallen\n", x->node));
+ }
+ }
+
+ /* x will make the follower -> leader transition */
+ follower_to_leader(x);
+ }
+
+ /* compute a new type for x */
+ old_type = x->type;
+ DB((dbg, LEVEL_3, "computing type of %+F\n", x->node));
+ compute(x);
+ if (x->type.tv != old_type.tv) {
+ verify_type(old_type, x->type);
+ DB((dbg, LEVEL_2, "node %+F has changed type from %+F to %+F\n", x->node, old_type, x->type));
+
+ if (x->on_fallen == 0) {
+ /* Add x to fallen. Nodes might fall from T -> const -> _|_, so check that they are
+ not already on the list. */
+ x->next = fallen;
+ x->on_fallen = 1;
+ fallen = x;
+ ++n_fallen;
+ DB((dbg, LEVEL_2, "Add node %+F to fallen\n", x->node));
+ }
+ for (i = get_irn_n_outs(x->node) - 1; i >= 0; --i) {
+ ir_node *succ = get_irn_out(x->node, i);
+ node_t *y = get_irn_node(succ);
+
+ /* Add y to y.partition.cprop. */
+ add_to_cprop(y, env);
+ }
+ }
+ }
+
+ if (n_fallen > 0 && n_fallen != X->n_leader) {
+ DB((dbg, LEVEL_2, "Splitting part%d by fallen\n", X->nr));
+ Y = split(&X, fallen, env);
+ /*
+ * We have split out fallen node. The type of the result
+ * partition is NOT set yet.
+ */
+ Y->type_is_T_or_C = 0;
+ } else {
+ Y = X;
+ }
+ /* remove the flags from the fallen list */
+ for (x = fallen; x != NULL; x = x->next)
+ x->on_fallen = 0;
+
+ if (old_type_was_T_or_C) {
+ node_t *y, *tmp;
+
+ /* check if some nodes will make the leader -> follower transition */
+ list_for_each_entry_safe(node_t, y, tmp, &Y->Leader, node_list) {
+ if (y->type.tv != tarval_top && ! is_con(y->type)) {
+ node_t *eq_node = identity(y);
+
+ if (eq_node != y && eq_node->part == y->part) {
+ DB((dbg, LEVEL_2, "Node %+F is a follower of %+F\n", y->node, eq_node->node));
+ /* move to Follower */
+ y->is_follower = 1;
+ list_del(&y->node_list);
+ list_add_tail(&y->node_list, &Y->Follower);
+ --Y->n_leader;
+
+ segregate_def_use_chain(y->node);
+ }
+ }
+ }
+ }
+ split_by(Y, env);
+ }
+} /* propagate */
+
+/**
+ * Get the leader for a given node from its congruence class.
+ *
+ * @param irn the node
+ */
+static ir_node *get_leader(node_t *node) {
+ partition_t *part = node->part;
+
+ if (part->n_leader > 1 || node->is_follower) {
+ if (node->is_follower) {
+ DB((dbg, LEVEL_2, "Replacing follower %+F\n", node->node));
+ }
+ else
+ DB((dbg, LEVEL_2, "Found congruence class for %+F\n", node->node));
+
+ return get_first_node(part)->node;
+ }
+ return node->node;
+} /* get_leader */
+
+/**
+ * Return non-zero if the control flow predecessor node pred
+ * is the only reachable control flow exit of its block.
+ *
+ * @param pred the control flow exit
+ */
+static int can_exchange(ir_node *pred) {
+ if (is_Start(pred))
+ return 0;
+ else if (is_Jmp(pred))
+ return 1;
+ else if (get_irn_mode(pred) == mode_T) {
+ int i, k;
+
+ /* if the predecessor block has more than one
+ reachable outputs we cannot remove the block */
+ k = 0;
+ for (i = get_irn_n_outs(pred) - 1; i >= 0; --i) {
+ ir_node *proj = get_irn_out(pred, i);
+ node_t *node;
+
+ /* skip non-control flow Proj's */
+ if (get_irn_mode(proj) != mode_X)
+ continue;
+
+ node = get_irn_node(proj);
+ if (node->type.tv == tarval_reachable) {
+ if (++k > 1)
+ return 0;
+ }
+ }
+ return 1;
+ }
+ return 0;
+} /* can_exchange */
+
+/**
+ * Block Post-Walker, apply the analysis results on control flow by
+ * shortening Phi's and Block inputs.
+ */
+static void apply_cf(ir_node *block, void *ctx) {
+ environment_t *env = ctx;
+ node_t *node = get_irn_node(block);
+ int i, j, k, n;
+ ir_node **ins, **in_X;
+ ir_node *phi, *next;
+
+ n = get_Block_n_cfgpreds(block);
+
+ if (node->type.tv == tarval_unreachable) {
+ env->modified = 1;
+
+ for (i = n - 1; i >= 0; --i) {
+ ir_node *pred = get_Block_cfgpred(block, i);
+
+ if (! is_Bad(pred)) {
+ node_t *pred_bl = get_irn_node(get_nodes_block(skip_Proj(pred)));
+
+ if (pred_bl->flagged == 0) {
+ pred_bl->flagged = 3;
+
+ if (pred_bl->type.tv == tarval_reachable) {
+ /*
+ * We will remove an edge from block to its pred.
+ * This might leave the pred block as an endless loop
+ */
+ if (! is_backedge(block, i))
+ keep_alive(pred_bl->node);
+ }
+ }
+ }
+ }
+
+ /* the EndBlock is always reachable even if the analysis
+ finds out the opposite :-) */
+ if (block != get_irg_end_block(current_ir_graph)) {
+ /* mark dead blocks */
+ set_Block_dead(block);
+ DB((dbg, LEVEL_1, "Removing dead %+F\n", block));
+ } else {
+ /* the endblock is unreachable */
+ set_irn_in(block, 0, NULL);
+ }
+ return;
+ }
+
+ if (n == 1) {
+ /* only one predecessor combine */
+ ir_node *pred = skip_Proj(get_Block_cfgpred(block, 0));
+
+ if (can_exchange(pred)) {
+ ir_node *new_block = get_nodes_block(pred);
+ DB((dbg, LEVEL_1, "Fuse %+F with %+F\n", block, new_block));
+ DBG_OPT_COMBO(block, new_block, FS_OPT_COMBO_CF);
+ exchange(block, new_block);
+ node->node = new_block;
+ env->modified = 1;
+ }
+ return;
+ }
+
+ NEW_ARR_A(ir_node *, in_X, n);
+ k = 0;
+ for (i = 0; i < n; ++i) {
+ ir_node *pred = get_Block_cfgpred(block, i);
+ node_t *node = get_irn_node(pred);
+
+ if (node->type.tv == tarval_reachable) {
+ in_X[k++] = pred;
+ } else {
+ DB((dbg, LEVEL_1, "Removing dead input %d from %+F (%+F)\n", i, block, pred));
+ if (! is_Bad(pred)) {
+ node_t *pred_bl = get_irn_node(get_nodes_block(skip_Proj(pred)));
+
+ if (pred_bl->flagged == 0) {
+ pred_bl->flagged = 3;
+
+ if (pred_bl->type.tv == tarval_reachable) {
+ /*
+ * We will remove an edge from block to its pred.
+ * This might leave the pred block as an endless loop
+ */
+ if (! is_backedge(block, i))
+ keep_alive(pred_bl->node);
+ }
+ }
+ }
+ }
+ }
+ if (k >= n)
+ return;
+
+ NEW_ARR_A(ir_node *, ins, n);
+ for (phi = get_Block_phis(block); phi != NULL; phi = next) {
+ node_t *node = get_irn_node(phi);
+
+ next = get_Phi_next(phi);
+ if (is_tarval(node->type.tv) && tarval_is_constant(node->type.tv)) {
+ /* this Phi is replaced by a constant */
+ tarval *tv = node->type.tv;
+ ir_node *c = new_r_Const(current_ir_graph, block, get_tarval_mode(tv), tv);
+
+ set_irn_node(c, node);
+ node->node = c;
+ DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", phi, c));
+ DBG_OPT_COMBO(phi, c, FS_OPT_COMBO_CONST);
+ exchange(phi, c);
+ env->modified = 1;
+ } else {
+ j = 0;
+ for (i = 0; i < n; ++i) {
+ node_t *pred = get_irn_node(get_Block_cfgpred(block, i));
+
+ if (pred->type.tv == tarval_reachable) {
+ ins[j++] = get_Phi_pred(phi, i);
+ }
+ }
+ if (j == 1) {
+ /* this Phi is replaced by a single predecessor */
+ ir_node *s = ins[0];
+ node_t *phi_node = get_irn_node(phi);
+
+ node->node = s;
+ DB((dbg, LEVEL_1, "%+F is replaced by %+F because of cf change\n", phi, s));
+ DBG_OPT_COMBO(phi, s, FS_OPT_COMBO_FOLLOWER);
+ exchange(phi, s);
+ phi_node->node = s;
+ env->modified = 1;
+ } else {
+ set_irn_in(phi, j, ins);
+ env->modified = 1;
+ }
+ }
+ }
+
+ if (k == 1) {
+ /* this Block has only one live predecessor */
+ ir_node *pred = skip_Proj(in_X[0]);
+
+ if (can_exchange(pred)) {
+ ir_node *new_block = get_nodes_block(pred);
+ DBG_OPT_COMBO(block, new_block, FS_OPT_COMBO_CF);
+ exchange(block, new_block);
+ node->node = new_block;
+ env->modified = 1;
+ }
+ } else {
+ set_irn_in(block, k, in_X);
+ env->modified = 1;
+ }
+}
+
+/**
+ * Post-Walker, apply the analysis results;
+ */
+static void apply_result(ir_node *irn, void *ctx) {
+ environment_t *env = ctx;
+ node_t *node = get_irn_node(irn);
+
+ if (is_Block(irn) || is_End(irn) || is_Bad(irn)) {
+ /* blocks already handled, do not touch the End node */
+ } else {
+ node_t *block = get_irn_node(get_nodes_block(irn));
+
+ if (block->type.tv == tarval_unreachable) {
+ ir_node *bad = get_irg_bad(current_ir_graph);
+
+ /* here, bad might already have a node, but this can be safely ignored
+ as long as bad has at least ONE valid node */
+ set_irn_node(bad, node);
+ node->node = bad;
+ DB((dbg, LEVEL_1, "%+F is unreachable\n", irn));
+ exchange(irn, bad);
+ env->modified = 1;
+ }
+ else if (node->type.tv == tarval_unreachable) {
+ /* don't kick away Unknown */
+ if (! is_Unknown(irn)) {
+ ir_node *bad = get_irg_bad(current_ir_graph);
+
+ /* see comment above */
+ set_irn_node(bad, node);
+ node->node = bad;
+ DB((dbg, LEVEL_1, "%+F is unreachable\n", irn));
+ exchange(irn, bad);
+ env->modified = 1;
+ }
+ }
+ else if (get_irn_mode(irn) == mode_X) {
+ if (is_Proj(irn)) {
+ /* leave or Jmp */
+ ir_node *cond = get_Proj_pred(irn);
+
+ if (is_Cond(cond)) {
+ node_t *sel = get_irn_node(get_Cond_selector(cond));
+
+ if (is_tarval(sel->type.tv) && tarval_is_constant(sel->type.tv)) {
+ /* Cond selector is a constant and the Proj is reachable, make a Jmp */
+ ir_node *jmp = new_r_Jmp(current_ir_graph, block->node);
+ set_irn_node(jmp, node);
+ node->node = jmp;
+ DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, jmp));
+ DBG_OPT_COMBO(irn, jmp, FS_OPT_COMBO_CF);
+ exchange(irn, jmp);
+ env->modified = 1;
+ }
+ }
+ }
+ } else {
+ /* normal data node */
+ if (is_tarval(node->type.tv) && tarval_is_constant(node->type.tv)) {
+ tarval *tv = node->type.tv;
+
+ /*
+ * Beware: never replace mode_T nodes by constants. Currently we must mark
+ * mode_T nodes with constants, but do NOT replace them.
+ */
+ if (! is_Const(irn) && get_irn_mode(irn) != mode_T) {
+ /* can be replaced by a constant */
+ ir_node *c = new_r_Const(current_ir_graph, block->node, get_tarval_mode(tv), tv);
+ set_irn_node(c, node);
+ node->node = c;
+ DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, c));
+ DBG_OPT_COMBO(irn, c, FS_OPT_COMBO_CONST);
+ exchange(irn, c);
+ env->modified = 1;
+ }
+ } else if (is_entity(node->type.sym.entity_p)) {
+ if (! is_SymConst(irn)) {
+ /* can be replaced by a Symconst */
+ ir_node *symc = new_r_SymConst(current_ir_graph, block->node, get_irn_mode(irn), node->type.sym, symconst_addr_ent);
+ set_irn_node(symc, node);
+ node->node = symc;
+
+ DB((dbg, LEVEL_1, "%+F is replaced by %+F\n", irn, symc));
+ DBG_OPT_COMBO(irn, symc, FS_OPT_COMBO_CONST);
+ exchange(irn, symc);
+ env->modified = 1;
+ }
+ } else if (is_Confirm(irn)) {
+ /* Confirms are always follower, but do not kill them here */
+ } else {
+ ir_node *leader = get_leader(node);
+
+ if (leader != irn) {
+ DB((dbg, LEVEL_1, "%+F from part%d is replaced by %+F\n", irn, node->part->nr, leader));
+ if (node->is_follower)
+ DBG_OPT_COMBO(irn, leader, FS_OPT_COMBO_FOLLOWER);
+ else
+ DBG_OPT_COMBO(irn, leader, FS_OPT_COMBO_CONGRUENT);
+ exchange(irn, leader);
+ env->modified = 1;
+ }
+ }
+ }
+ }
+} /* apply_result */
+
+/**
+ * Fix the keep-alives by deleting unreachable ones.
+ */
+static void apply_end(ir_node *end, environment_t *env) {
+ int i, j, n = get_End_n_keepalives(end);
+ ir_node **in;
+
+ if (n > 0)
+ NEW_ARR_A(ir_node *, in, n);
+
+ /* fix the keep alive */
+ for (i = j = 0; i < n; i++) {
+ ir_node *ka = get_End_keepalive(end, i);
+ node_t *node = get_irn_node(ka);
+
+ if (! is_Block(ka))
+ node = get_irn_node(get_nodes_block(ka));
+
+ if (node->type.tv != tarval_unreachable)
+ in[j++] = ka;
+ }
+ if (j != n) {
+ set_End_keepalives(end, j, in);
+ env->modified = 1;
+ }
+} /* apply_end */
+
+#define SET(code) op_##code->ops.generic = (op_func)compute_##code
+
+/**
+ * sets the generic functions to compute.
+ */
+static void set_compute_functions(void) {
+ int i;
+
+ /* set the default compute function */
+ for (i = get_irp_n_opcodes() - 1; i >= 0; --i) {
+ ir_op *op = get_irp_opcode(i);
+ op->ops.generic = (op_func)default_compute;
+ }
+
+ /* set specific functions */
+ SET(Block);
+ SET(Unknown);
+ SET(Bad);
+ SET(Jmp);
+ SET(Phi);
+ SET(Add);
+ SET(Sub);
+ SET(Eor);
+ SET(SymConst);
+ SET(Cmp);
+ SET(Proj);
+ SET(Confirm);
+ SET(End);
+
+ if (op_Max != NULL)
+ SET(Max);
+ if (op_Min != NULL)
+ SET(Min);
+
+} /* set_compute_functions */
+
+static int dump_partition_hook(FILE *F, ir_node *n, ir_node *local) {
+#ifdef DEBUG_libfirm
+ ir_node *irn = local != NULL ? local : n;
+ node_t *node = get_irn_node(irn);
+
+ ir_fprintf(F, "info2 : \"partition %u type %+F\"\n", node->part->nr, node->type);
+ return 1;
+#endif