+static void assign_tree_postdom_pre_order(ir_node *bl, void *data)
+{
+ unsigned *num = data;
+ ir_dom_info *bi = get_pdom_info(bl);
+
+ bi->tree_pre_num = (*num)++;
+}
+
+static void assign_tree_postdom_pre_order_max(ir_node *bl, void *data)
+{
+ ir_dom_info *bi = get_pdom_info(bl);
+ ir_node *p;
+ unsigned max = 0;
+ unsigned children = 0;
+ (void) data;
+
+ for(p = bi->first; p; p = get_pdom_info(p)->next) {
+ unsigned max_p = get_pdom_info(p)->max_subtree_pre_num;
+ max = max > max_p ? max : max_p;
+ children++;
+ }
+
+ bi->max_subtree_pre_num = children > 0 ? max : bi->tree_pre_num;
+ assert(bi->max_subtree_pre_num >= bi->tree_pre_num);
+}
+
+/*--------------------------------------------------------------------*/
+/* Building and Removing the dominator data structure */
+/*--------------------------------------------------------------------*/
+
+/**
+ * count the number of blocks and clears the post dominance info
+ */
+static void count_and_init_blocks_pdom(ir_node *bl, void *env) {
+ int *n_blocks = (int *) env;
+ (*n_blocks) ++;
+
+ memset(get_pdom_info(bl), 0, sizeof(ir_dom_info));
+ set_Block_ipostdom(bl, NULL);
+ set_Block_postdom_pre_num(bl, -1);
+ set_Block_postdom_depth(bl, -1);
+}
+
+/** temporary type used while constructing the dominator / post dominator tree. */
+typedef struct tmp_dom_info {
+ ir_node *block; /**< backlink */
+
+ struct tmp_dom_info *semi; /**< semidominator */
+ struct tmp_dom_info *parent;
+ struct tmp_dom_info *label; /**< used for LINK and EVAL */
+ struct tmp_dom_info *ancestor;/**< used for LINK and EVAL */
+ struct tmp_dom_info *dom; /**< After step 3, if the semidominator of w is
+ its immediate dominator, then w->dom is the
+ immediate dominator of w. Otherwise w->dom
+ is a vertex v whose number is smaller than
+ w and whose immediate dominator is also w's
+ immediate dominator. After step 4, w->dom
+ is the immediate dominator of w. */
+ struct tmp_dom_info *bucket; /**< set of vertices with same semidominator */
+} tmp_dom_info;
+
+/** Struct to pass info through walker. */
+typedef struct {
+ tmp_dom_info *d;
+ int used;
+} dom_env;
+
+
+/**
+ * Walks Blocks along the out data structure. If recursion started with
+ * Start block misses control dead blocks.
+ */
+static void init_tmp_dom_info(ir_node *bl, tmp_dom_info *parent,
+ tmp_dom_info *tdi_list, int *used, int n_blocks) {
+ tmp_dom_info *tdi;
+ int i;
+
+ assert(is_Block(bl));
+ if (get_irg_block_visited(current_ir_graph) == get_Block_block_visited(bl))
+ return;
+ mark_Block_block_visited(bl);
+ set_Block_dom_pre_num(bl, *used);
+
+ assert(*used < n_blocks);
+ tdi = &tdi_list[*used];
+ ++(*used);
+
+ tdi->semi = tdi;
+ tdi->label = tdi;
+ tdi->ancestor = NULL;
+ tdi->bucket = NULL;
+ tdi->parent = parent;
+ tdi->block = bl;
+
+ /* Iterate */
+ for (i = get_Block_n_cfg_outs_ka(bl) - 1; i >= 0; --i) {
+ ir_node *pred = get_Block_cfg_out_ka(bl, i);
+ assert(is_Block(pred));
+ init_tmp_dom_info(pred, tdi, tdi_list, used, n_blocks);
+ }
+}
+
+/**
+ * Walks Blocks along the control flow. If recursion started with
+ * End block misses blocks in endless loops.
+ */
+static void init_tmp_pdom_info(ir_node *bl, tmp_dom_info *parent,
+ tmp_dom_info *tdi_list, int* used, int n_blocks) {
+ tmp_dom_info *tdi;
+ int i;
+
+ assert(is_Block(bl));
+ if (get_irg_block_visited(current_ir_graph) == get_Block_block_visited(bl))
+ return;
+ mark_Block_block_visited(bl);
+ set_Block_postdom_pre_num(bl, *used);
+
+ assert(*used < n_blocks);
+ tdi = &tdi_list[*used];
+ ++(*used);
+
+ tdi->semi = tdi;
+ tdi->label = tdi;
+ tdi->ancestor = NULL;
+ tdi->bucket = NULL;
+ tdi->parent = parent;
+ tdi->block = bl;
+
+ /* Iterate */
+ for (i = get_Block_n_cfgpreds(bl) - 1; i >= 0; --i) {
+ ir_node *pred = get_Block_cfgpred_block(bl, i);
+ if (is_Bad(pred))
+ continue;
+ assert(is_Block(pred));
+ init_tmp_pdom_info(pred, tdi, tdi_list, used, n_blocks);
+ }
+
+ /* Handle keep-alives. Note that the preprocessing
+ in init_construction() had already killed all
+ phantom keep-alive edges. All remaining block keep-alives
+ are really edges to endless loops.
+ */
+ if (bl == get_irg_end_block(current_ir_graph)) {
+ ir_node *end = get_irg_end(current_ir_graph);
+
+ for (i = get_irn_arity(end) - 1; i >= 0; --i) {
+ ir_node *pred = get_irn_n(end, i);
+
+ if (is_Block(pred))
+ init_tmp_pdom_info(pred, tdi, tdi_list, used, n_blocks);
+ }
+ }
+}
+
+static void dom_compress(tmp_dom_info *v) {
+ assert (v->ancestor);
+ if (v->ancestor->ancestor) {
+ dom_compress (v->ancestor);
+ if (v->ancestor->label->semi < v->label->semi) {
+ v->label = v->ancestor->label;
+ }
+ v->ancestor = v->ancestor->ancestor;
+ }
+}
+
+/**
+ * if V is a root, return v, else return the vertex u, not being the
+ * root, with minimum u->semi on the path from v to its root.
+ */
+INLINE static tmp_dom_info *dom_eval(tmp_dom_info *v) {
+ if (!v->ancestor) return v;
+ dom_compress (v);
+ return v->label;
+}
+
+/** make V W's ancestor */
+INLINE static void dom_link(tmp_dom_info *v, tmp_dom_info *w) {
+ w->ancestor = v;
+}
+
+/**
+ * Walker: count the number of blocks and clears the dominance info
+ */
+static void count_and_init_blocks_dom(ir_node *bl, void *env) {
+ int *n_blocks = (int *) env;
+ (*n_blocks) ++;
+
+ memset(get_dom_info(bl), 0, sizeof(ir_dom_info));
+ set_Block_idom(bl, NULL);
+ set_Block_dom_pre_num(bl, -1);
+ set_Block_dom_depth(bl, -1);
+}
+
+/**
+ * Initialize the dominance/postdominance construction:
+ *
+ * - count the number of blocks
+ * - clear the dominance info
+ * - remove Block-keepalives of live blocks to reduce
+ * the number of "phantom" block edges
+ *
+ * @param irg the graph
+ * @param pre a walker function that will be called for every block in the graph
+ */
+static int init_construction(ir_graph *irg, irg_walk_func *pre) {
+ ir_graph *rem = current_ir_graph;
+ ir_node *end;
+ int arity;
+ int n_blocks = 0;
+
+ current_ir_graph = irg;
+
+ /* this visits only the reachable blocks */
+ irg_block_walk(get_irg_end_block(irg), pre, NULL, &n_blocks);
+
+ /* now visit the unreachable (from End) Blocks and remove unnecessary keep-alives */
+ end = get_irg_end(irg);
+ arity = get_End_n_keepalives(end);
+ if (arity) { /* we have keep-alives */
+ ir_node **in;
+ int i, j;
+
+ NEW_ARR_A(ir_node *, in, arity);
+ for (i = j = 0; i < arity; i++) {
+ ir_node *pred = get_End_keepalive(end, i);
+
+ if (is_Block(pred)) {
+ if (Block_block_visited(pred))
+ continue;
+
+ /* we found an endless loop */
+ dec_irg_block_visited(irg);
+ irg_block_walk(pred, pre, NULL, &n_blocks);
+ }
+ in[j++] = pred;
+ }
+ if (j != arity) {
+ /* we kill some Block keep-alives */
+ set_End_keepalives(end, j, in);
+ set_irg_outs_inconsistent(irg);
+ }
+ }
+
+ current_ir_graph = rem;
+ return n_blocks;
+}
+
+
+/* Computes the dominator trees. Sets a flag in irg to "dom_consistent".
+ If the control flow of the graph is changed this flag must be set to
+ "dom_inconsistent". */
+void compute_doms(ir_graph *irg) {
+ ir_graph *rem = current_ir_graph;
+ int n_blocks, used, i, j;
+ tmp_dom_info *tdi_list; /* Ein Golf? */
+
+ current_ir_graph = irg;
+
+ /* Update graph state */
+ assert(get_irg_phase_state(irg) != phase_building);
+ irg->dom_state = dom_consistent;
+
+ /* Count the number of blocks in the graph. */
+ n_blocks = init_construction(irg, count_and_init_blocks_dom);
+
+ /* Memory for temporary information. */
+ tdi_list = xcalloc(n_blocks, sizeof(tdi_list[0]));
+
+ /* We need the out data structure. */
+ assure_irg_outs(irg);
+
+ /* this with a standard walker as passing the parent to the sons isn't
+ simple. */
+ used = 0;
+ inc_irg_block_visited(irg);
+ init_tmp_dom_info(get_irg_start_block(irg), NULL, tdi_list, &used, n_blocks);
+ /* If not all blocks are reachable from Start by out edges this assertion
+ fails.
+ assert(used == n_blocks && "Precondition for dom construction violated"); */
+ assert(used <= n_blocks && "Precondition for dom construction violated");
+ n_blocks = used;
+
+
+ for (i = n_blocks-1; i > 0; i--) { /* Don't iterate the root, it's done. */
+ int irn_arity;
+ tmp_dom_info *w = &tdi_list[i];
+ tmp_dom_info *v;
+
+ /* Step 2 */
+ irn_arity = get_irn_arity(w->block);
+ for (j = 0; j < irn_arity; j++) {
+ ir_node *pred = get_Block_cfgpred_block(w->block, j);
+ tmp_dom_info *u;
+
+ if (is_Bad(pred) || (get_Block_dom_pre_num (pred) == -1))
+ continue; /* control-dead */
+
+ u = dom_eval (&tdi_list[get_Block_dom_pre_num(pred)]);
+ if (u->semi < w->semi) w->semi = u->semi;
+ }
+
+ /* handle keep-alives if we are at the end block */
+ if (w->block == get_irg_end_block(irg)) {
+ ir_node *end = get_irg_end(irg);
+
+ irn_arity = get_irn_arity(end);
+ for (j = 0; j < irn_arity; j++) {
+ ir_node *pred = get_irn_n(end, j);
+ tmp_dom_info *u;
+
+ if (is_no_Block(pred) || get_Block_dom_pre_num(pred) == -1)
+ continue; /* control-dead */
+
+ u = dom_eval (&tdi_list[get_Block_dom_pre_num(pred)]);
+ if (u->semi < w->semi) w->semi = u->semi;
+ }
+ }
+
+ /* Add w to w->semi's bucket. w is in exactly one bucket, so
+ buckets can been implemented as linked lists. */
+ w->bucket = w->semi->bucket;
+ w->semi->bucket = w;
+
+ dom_link (w->parent, w);
+
+ /* Step 3 */
+ while (w->parent->bucket) {
+ tmp_dom_info *u;
+ v = w->parent->bucket;
+ /* remove v from w->parent->bucket */
+ w->parent->bucket = v->bucket;
+ v->bucket = NULL;
+
+ u = dom_eval (v);
+ if (u->semi < v->semi)
+ v->dom = u;
+ else
+ v->dom = w->parent;
+ }
+ }
+ /* Step 4 */
+ tdi_list[0].dom = NULL;
+ set_Block_idom(tdi_list[0].block, NULL);
+ set_Block_dom_depth(tdi_list[0].block, 1);
+ for (i = 1; i < n_blocks; i++) {
+ tmp_dom_info *w = &tdi_list[i];
+ int depth;
+
+ if (! w->dom)
+ continue; /* control dead */
+
+ if (w->dom != w->semi) w->dom = w->dom->dom;
+ set_Block_idom(w->block, w->dom->block);
+
+ /* blocks dominated by dead one's are still dead */
+ depth = get_Block_dom_depth(w->dom->block);
+ if (depth > 0)
+ ++depth;
+ set_Block_dom_depth(w->block, depth);
+ }
+
+ /* clean up */
+ free(tdi_list);
+
+ /* Do a walk over the tree and assign the tree pre orders. */
+ {
+ unsigned tree_pre_order = 0;
+ dom_tree_walk_irg(irg, assign_tree_dom_pre_order,
+ assign_tree_dom_pre_order_max, &tree_pre_order);
+ }
+ current_ir_graph = rem;
+}
+
+void assure_doms(ir_graph *irg) {
+ if (get_irg_dom_state(irg) != dom_consistent)
+ compute_doms(irg);
+}
+
+void free_dom(ir_graph *irg) {
+ /* Update graph state */
+ assert(get_irg_phase_state(irg) != phase_building);
+ irg->dom_state = dom_none;
+
+ /* With the implementation right now there is nothing to free,
+ but better call it anyways... */
+}
+
+/* Computes the post dominator trees. Sets a flag in irg to "dom_consistent".
+ If the control flow of the graph is changed this flag must be set to
+ "dom_inconsistent". */
+void compute_postdoms(ir_graph *irg) {
+ ir_graph *rem = current_ir_graph;
+ int n_blocks, used, i, j;
+ tmp_dom_info *tdi_list;
+
+ current_ir_graph = irg;
+
+ /* Update graph state */
+ assert(get_irg_phase_state(irg) != phase_building);
+ irg->pdom_state = dom_consistent;
+
+ /* Count the number of blocks in the graph. */
+ n_blocks = init_construction(irg, count_and_init_blocks_pdom);
+
+ /* Memory for temporary information. */
+ tdi_list = xcalloc(n_blocks, sizeof(tdi_list[0]));
+
+ /* We need the out data structure. */
+ assure_irg_outs(irg);
+
+ /* this with a standard walker as passing the parent to the sons isn't
+ simple. */
+ used = 0;
+ inc_irg_block_visited(irg);
+ init_tmp_pdom_info(get_irg_end_block(irg), NULL, tdi_list, &used, n_blocks);
+ /* If not all blocks are reachable from End by cfg edges this assertion
+ fails.
+ assert(used == n_blocks && "Precondition for dom construction violated"); */
+ n_blocks = used;
+
+
+ for (i = n_blocks-1; i > 0; i--) { /* Don't iterate the root, it's done. */
+ int irn_arity;
+ tmp_dom_info *w = &tdi_list[i];
+ tmp_dom_info *v;
+
+ /* Step 2 */
+ irn_arity = get_Block_n_cfg_outs_ka(w->block);
+ for (j = 0; j < irn_arity; j++) {
+ ir_node *succ = get_Block_cfg_out_ka(w->block, j);
+ tmp_dom_info *u;
+
+ if (get_Block_postdom_pre_num (succ) == -1)
+ continue; /* endless-loop */
+
+ u = dom_eval (&tdi_list[get_Block_postdom_pre_num(succ)]);
+ if (u->semi < w->semi) w->semi = u->semi;
+ }
+ /* Add w to w->semi's bucket. w is in exactly one bucket, so
+ buckets can be implemented as linked lists. */
+ w->bucket = w->semi->bucket;
+ w->semi->bucket = w;
+
+ dom_link (w->parent, w);
+
+ /* Step 3 */
+ while (w->parent->bucket) {
+ tmp_dom_info *u;
+ v = w->parent->bucket;
+ /* remove v from w->parent->bucket */
+ w->parent->bucket = v->bucket;
+ v->bucket = NULL;
+
+ u = dom_eval(v);
+ if (u->semi < v->semi)
+ v->dom = u;
+ else
+ v->dom = w->parent;
+ }
+ }
+ /* Step 4 */
+ tdi_list[0].dom = NULL;
+ set_Block_ipostdom(tdi_list[0].block, NULL);
+ set_Block_postdom_depth(tdi_list[0].block, 1);
+ for (i = 1; i < n_blocks; i++) {
+ tmp_dom_info *w = &tdi_list[i];
+
+ if (w->dom != w->semi) w->dom = w->dom->dom;
+ set_Block_ipostdom(w->block, w->dom->block);
+ set_Block_postdom_depth(w->block, get_Block_postdom_depth(w->dom->block) + 1);
+ }
+
+ /* clean up */
+ free(tdi_list);
+
+ /* Do a walk over the tree and assign the tree pre orders. */
+ {
+ unsigned tree_pre_order = 0;
+ postdom_tree_walk_irg(irg, assign_tree_postdom_pre_order,
+ assign_tree_postdom_pre_order_max, &tree_pre_order);
+ }
+ current_ir_graph = rem;
+}
+
+void assure_postdoms(ir_graph *irg) {
+ if (get_irg_postdom_state(irg) != dom_consistent)
+ compute_postdoms(irg);
+}
+
+void free_postdom(ir_graph *irg) {
+ /* Update graph state */
+ assert(get_irg_phase_state(irg) != phase_building);
+ irg->pdom_state = dom_none;
+
+ /* With the implementation right now there is nothing to free,
+ but better call it anyways... */
+}