/*
- * Project: libFIRM
- * File name: ir/ana/irdom.c
- * Purpose: Construct and access dominator tree.
- * Author: Goetz Lindenmaier
- * Modified by:
- * Created: 2.2002
- * CVS-ID: $Id$
- * Copyright: (c) 2002-2003 Universität Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
*/
-#ifdef HAVE_CONFIG_H
+/**
+ * @file
+ * @brief Construct and access dominator / post dominator tree.
+ * @author Goetz Lindenmaier, Michael Beck, Rubino Geiss
+ * @date 2.2002
+ */
#include "config.h"
-#endif
-#ifdef HAVE_STRING_H
#include <string.h>
-#endif
#include "irouts.h"
#include "xmalloc.h"
#include "irgwalk.h"
#include "irdom_t.h"
-#include "irgraph_t.h" /* To access state field. */
+#include "irgraph_t.h"
#include "irnode_t.h"
#include "ircons_t.h"
+#include "array_t.h"
+#include "iredges.h"
+
+
+#define get_dom_info(bl) (&(bl)->attr.block.dom)
+#define get_pdom_info(bl) (&(bl)->attr.block.pdom)
+
+ir_node *get_Block_idom(const ir_node *bl)
+{
+ if (get_Block_dom_depth(bl) == -1) {
+ /* This block is not reachable from Start */
+ ir_graph *irg = get_irn_irg(bl);
+ return new_r_Bad(irg, mode_BB);
+ }
+ return get_dom_info(bl)->idom;
+}
+
+void set_Block_idom(ir_node *bl, ir_node *n)
+{
+ ir_dom_info *bli = get_dom_info(bl);
+
+ assert(is_Block(bl));
+
+ /* Set the immediate dominator of bl to n */
+ bli->idom = n;
+
+ /*
+ * If we don't set the root of the dominator tree
+ * Append bl to the dominates queue of n.
+ */
+ if (n != NULL) {
+ ir_dom_info *ni = get_dom_info(n);
+
+ bli->next = ni->first;
+ ni->first = bl;
+ }
+}
+
+ir_node *get_Block_ipostdom(const ir_node *bl)
+{
+ if (get_Block_postdom_depth(bl) == -1) {
+ /* This block is not reachable from Start */
+ ir_graph *irg = get_irn_irg(bl);
+ return new_r_Bad(irg, mode_BB);
+ }
+ return get_pdom_info(bl)->idom;
+}
+
+void set_Block_ipostdom(ir_node *bl, ir_node *n)
+{
+ ir_dom_info *bli = get_pdom_info(bl);
+
+ assert(is_Block(bl));
+
+ /* Set the immediate post dominator of bl to n */
+ bli->idom = n;
+
+ /*
+ * If we don't set the root of the post dominator tree
+ * Append bl to the post dominates queue of n.
+ */
+ if (n != NULL) {
+ ir_dom_info *ni = get_pdom_info(n);
+
+ bli->next = ni->first;
+ ni->first = bl;
+ }
+}
+
+int get_Block_dom_pre_num(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_dom_info(bl)->pre_num;
+}
+
+void set_Block_dom_pre_num(ir_node *bl, int num)
+{
+ assert(is_Block(bl));
+ get_dom_info(bl)->pre_num = num;
+}
+
+int get_Block_dom_depth(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_dom_info(bl)->dom_depth;
+}
+
+void set_Block_dom_depth(ir_node *bl, int depth)
+{
+ assert(is_Block(bl));
+ get_dom_info(bl)->dom_depth = depth;
+}
+
+
+int get_Block_postdom_pre_num(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_pdom_info(bl)->pre_num;
+}
+
+void set_Block_postdom_pre_num(ir_node *bl, int num)
+{
+ assert(is_Block(bl));
+ get_pdom_info(bl)->pre_num = num;
+}
+
+int get_Block_postdom_depth(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_pdom_info(bl)->dom_depth;
+}
+
+void set_Block_postdom_depth(ir_node *bl, int depth)
+{
+ assert(is_Block(bl));
+ get_pdom_info(bl)->dom_depth = depth;
+}
+
+unsigned get_Block_dom_tree_pre_num(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_dom_info(bl)->tree_pre_num;
+}
+
+unsigned get_Block_dom_max_subtree_pre_num(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_dom_info(bl)->max_subtree_pre_num;
+}
+
+unsigned get_Block_pdom_tree_pre_num(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_pdom_info(bl)->tree_pre_num;
+}
+
+unsigned get_Block_pdom_max_subtree_pre_num(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_pdom_info(bl)->max_subtree_pre_num;
+}
+
+int block_dominates(const ir_node *a, const ir_node *b)
+{
+ const ir_dom_info *ai, *bi;
+
+ if (is_Block(a) && is_Block(b)) {
+ ai = get_dom_info(a);
+ bi = get_dom_info(b);
+ return bi->tree_pre_num - ai->tree_pre_num
+ <= ai->max_subtree_pre_num - ai->tree_pre_num;
+ }
+
+ return 0;
+}
+
+int block_strictly_dominates(const ir_node *a, const ir_node *b)
+{
+ return (a != b) && block_dominates(a, b);
+}
+
+ir_node *node_smallest_common_dominator(ir_node *a, ir_node *b)
+{
+ ir_node *bl_a = is_Block(a) ? a : get_nodes_block(a);
+ ir_node *bl_b = is_Block(b) ? b : get_nodes_block(b);
+ ir_node *dom_bl = NULL;
+
+ /* Check if block of a dominates block of b */
+ if (block_dominates(bl_a, bl_b))
+ dom_bl = bl_a;
+ /* Check if block of b dominates block of a */
+ else if (block_dominates(bl_b, bl_a))
+ dom_bl = bl_b;
+ else {
+ /* walk up dominator tree and search for first block dominating a and b */
+ while (! dom_bl) {
+ bl_a = get_Block_idom(bl_a);
+
+ assert(! is_Bad(bl_a) && "block is dead?");
+
+ if (block_dominates(bl_a, bl_b))
+ dom_bl = bl_a;
+ }
+ }
+
+ return dom_bl;
+}
+
+/* Get the first node in the list of nodes dominated by a given block. */
+ir_node *get_Block_dominated_first(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_dom_info(bl)->first;
+}
+
+ir_node *get_Block_dominated_next(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_dom_info(bl)->next;
+}
-/*--------------------------------------------------------------------*/
-/** Accessing the dominator data structures **/
-/*--------------------------------------------------------------------*/
+int block_postdominates(const ir_node *a, const ir_node *b)
+{
+ const ir_dom_info *ai, *bi;
+
+ if (is_Block(a) && is_Block(b)) {
+ ai = get_pdom_info(a);
+ bi = get_pdom_info(b);
+ return bi->tree_pre_num - ai->tree_pre_num
+ <= ai->max_subtree_pre_num - ai->tree_pre_num;
+ }
-ir_node *get_Block_idom(ir_node *bl) {
- assert(get_irn_op(bl) == op_Block);
- if (get_Block_dom_depth(bl) == -1) {
- /* This block is not reachable from Start */
- return new_Bad();
- }
- return bl->attr.block.dom.idom;
+ return 0;
}
-void set_Block_idom(ir_node *bl, ir_node *n) {
- assert(get_irn_op(bl) == op_Block);
- bl->attr.block.dom.idom = n;
+int block_strictly_postdominates(const ir_node *a, const ir_node *b)
+{
+ return (a != b) && block_postdominates(a, b);
}
-int get_Block_pre_num(ir_node *bl) {
- assert(get_irn_op(bl) == op_Block);
- return bl->attr.block.dom.pre_num;
+ir_node *get_Block_postdominated_first(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_pdom_info(bl)->first;
}
-void set_Block_pre_num(ir_node *bl, int num) {
- assert(get_irn_op(bl) == op_Block);
- bl->attr.block.dom.pre_num = num;
+ir_node *get_Block_postdominated_next(const ir_node *bl)
+{
+ assert(is_Block(bl));
+ return get_pdom_info(bl)->next;
}
-int get_Block_dom_depth(ir_node *bl) {
- assert(get_irn_op(bl) == op_Block);
- return bl->attr.block.dom.dom_depth;
+void dom_tree_walk(ir_node *bl, irg_walk_func *pre,
+ irg_walk_func *post, void *env)
+{
+ ir_node *p;
+
+ if (pre)
+ pre(bl, env);
+
+ dominates_for_each(bl, p) {
+ dom_tree_walk(p, pre, post, env);
+ }
+
+ if (post)
+ post(bl, env);
}
-void set_Block_dom_depth(ir_node *bl, int depth) {
- assert(get_irn_op(bl) == op_Block);
- bl->attr.block.dom.dom_depth = depth;
+void postdom_tree_walk(ir_node *bl, irg_walk_func *pre,
+ irg_walk_func *post, void *env)
+{
+ ir_node *p;
+
+ if (pre)
+ pre(bl, env);
+
+ postdominates_for_each(bl, p) {
+ postdom_tree_walk(p, pre, post, env);
+ }
+
+ if (post)
+ post(bl, env);
}
+void dom_tree_walk_irg(ir_graph *irg, irg_walk_func *pre,
+ irg_walk_func *post, void *env)
+{
+ /* The root of the dominator tree should be the Start block. */
+ ir_node *root = get_irg_start_block(irg);
+
+ assert(irg_has_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE)
+ && "The dominators of the irg must be consistent");
+ assert(root && "The start block of the graph is NULL?");
+ assert(get_dom_info(root)->idom == NULL
+ && "The start node in the graph must be the root of the dominator tree");
+ dom_tree_walk(root, pre, post, env);
+}
+void postdom_tree_walk_irg(ir_graph *irg, irg_walk_func *pre,
+ irg_walk_func *post, void *env)
+{
+ /* The root of the post dominator tree should be the End block. */
+ ir_node *root = get_irg_end_block(irg);
+
+ assert(irg_has_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_POSTDOMINANCE)
+ && "The dominators of the irg must be consistent");
+ assert(root && "The end block of the graph is NULL?");
+ assert(get_pdom_info(root)->idom == NULL
+ && "The End block node in the graph must be the root of the post dominator tree");
+ postdom_tree_walk(root, pre, post, env);
+}
-/*--------------------------------------------------------------------*/
-/* Building and Removing the dominator datastructure */
-/*--------------------------------------------------------------------*/
-static void count_and_init_blocks(ir_node *bl, void *env) {
- int *n_blocks = (int *) env;
- (*n_blocks) ++;
+static void assign_tree_dom_pre_order(ir_node *bl, void *data)
+{
+ unsigned *num = (unsigned*) data;
+ ir_dom_info *bi = get_dom_info(bl);
- set_Block_idom(bl, NULL);
- set_Block_pre_num(bl, -1);
- set_Block_dom_depth(bl, -1);
+ bi->tree_pre_num = (*num)++;
}
-/* temporary type used while constructing the dominator tree. */
+static void assign_tree_dom_pre_order_max(ir_node *bl, void *data)
+{
+ ir_dom_info *bi = get_dom_info(bl);
+ ir_node *p;
+ unsigned max = 0;
+ unsigned children = 0;
+ (void) data;
+
+ for (p = bi->first; p; p = get_dom_info(p)->next) {
+ unsigned max_p = get_dom_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);
+}
+
+static void assign_tree_postdom_pre_order(ir_node *bl, void *data)
+{
+ unsigned *num = (unsigned*) 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);
+}
+
+/**
+ * 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 */
+ 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. */
+/** Struct to pass info through walker. */
typedef struct {
- tmp_dom_info *d;
- int used;
-
+ tmp_dom_info *d;
+ int used;
} dom_env;
-/* Walks Blocks along the out datastructure. If recursion started with
- Start block misses control dead blocks. */
+/**
+ * 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) {
- tmp_dom_info *tdi;
- int i;
-
- assert(get_irn_op(bl) == op_Block);
- if (get_irg_block_visited(current_ir_graph) == get_Block_block_visited(bl))
- return;
- mark_Block_block_visited(bl);
- set_Block_pre_num(bl, *used);
-
- 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 = 0; i < get_Block_n_cfg_outs(bl); i++) {
- ir_node *pred = get_Block_cfg_out(bl, i);
- assert(get_irn_opcode(pred) == iro_Block);
- init_tmp_dom_info(pred, tdi, tdi_list, used);
- }
-}
-
-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;
-}
-
-/* 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(current_ir_graph) != phase_building);
- current_ir_graph->dom_state = dom_consistent;
-
- /* Count the number of blocks in the graph. */
- n_blocks = 0;
- irg_block_walk(get_irg_end(current_ir_graph), count_and_init_blocks, NULL, &n_blocks);
-
- /* Memory for temporary information. */
- tdi_list = xmalloc(n_blocks * sizeof(tmp_dom_info));
- memset(tdi_list, 0, n_blocks * sizeof(tmp_dom_info));
-
- /* We need the out datastructure. */
- if (current_ir_graph->outs_state != outs_consistent)
- compute_outs(current_ir_graph);
-
- /* this with a standard walker as passing the parent to the sons isn't
- simple. */
- used = 0;
- inc_irg_block_visited(current_ir_graph);
- init_tmp_dom_info(get_irg_start_block(current_ir_graph), NULL, tdi_list, &used);
- /* If not all blocks are reachable from Start by out 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_irn_arity(w->block);
- for (j = 0; j < irn_arity; j++) {
- ir_node *cf_op = get_Block_cfgpred(w->block, j);
- ir_node *pred = get_nodes_block(cf_op);
- tmp_dom_info *u;
-
- if ((is_Bad(cf_op)) || (is_Bad(pred)) ||
- (get_Block_pre_num (pred) == -1))
- continue; /* control-dead */
-
- u = dom_eval (&tdi_list[get_Block_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 ben 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];
-
- if (w->dom != w->semi) w->dom = w->dom->dom;
- set_Block_idom(w->block, w->dom->block);
- set_Block_dom_depth(w->block, get_Block_dom_depth(w->dom->block) + 1);
- }
-
- /* clean up */
- /* free(tdi_list); @@@ does not work !!?? */
- current_ir_graph = rem;
-}
-
-void free_dom_and_peace(ir_graph *irg) {
- /* Update graph state */
- assert(get_irg_phase_state(current_ir_graph) != phase_building);
- current_ir_graph->dom_state = dom_none;
-
- /* With the implementation right now there is nothing to free,
- but better call it anyways... */
+ tmp_dom_info *tdi_list, int *used, int n_blocks)
+{
+ tmp_dom_info *tdi;
+ int i;
+
+ if (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);
+ /* can happen for half-optimized dead code (I've seen this in student
+ projects */
+ if (!is_Block(pred))
+ continue;
+
+ 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;
+
+ 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;
+ 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);
+}
+
+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(!irg_is_constrained(irg, IR_GRAPH_CONSTRAINT_CONSTRUCTION));
+
+ /* Count the number of blocks in the graph. */
+ n_blocks = 0;
+ irg_block_walk_graph(irg, count_and_init_blocks_dom, NULL, &n_blocks);
+
+ /* Memory for temporary information. */
+ tdi_list = XMALLOCNZ(tmp_dom_info, n_blocks);
+
+ /* 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. */
+ tmp_dom_info *w = &tdi_list[i];
+ ir_node *block = w->block;
+ tmp_dom_info *v;
+ int irn_arity;
+
+ /* Step 2 */
+ irn_arity = get_irn_arity(block);
+ for (j = 0; j < irn_arity; j++) {
+ ir_node *pred = get_Block_cfgpred(block, j);
+ ir_node *pred_block = get_nodes_block(pred);
+ tmp_dom_info *u;
+
+ if (is_Bad(pred) || (get_Block_dom_pre_num (pred_block) == -1))
+ continue; /* unreachable */
+
+ u = dom_eval (&tdi_list[get_Block_dom_pre_num(pred_block)]);
+ if (u->semi < w->semi)
+ w->semi = u->semi;
+ }
+
+ /* handle keep-alives if we are at the end block */
+ if (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_Block(pred) || get_Block_dom_pre_num(pred) == -1)
+ continue; /* unreachable */
+
+ 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(get_irg_start_block(irg), assign_tree_dom_pre_order,
+ assign_tree_dom_pre_order_max, &tree_pre_order);
+ }
+ current_ir_graph = rem;
+ add_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
+}
+
+void assure_doms(ir_graph *irg)
+{
+ if (! irg_has_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE))
+ compute_doms(irg);
+}
+
+void free_dom(ir_graph *irg)
+{
+ /* Update graph state */
+ clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE);
+
+ /* With the implementation right now there is nothing to free */
+
+ /* free dominance frontiers */
+ ir_free_dominance_frontiers(irg);
+}
+
+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(!irg_is_constrained(irg, IR_GRAPH_CONSTRAINT_CONSTRUCTION));
+
+ /* Count the number of blocks in the graph. */
+ n_blocks = 0;
+ irg_block_walk_graph(irg, count_and_init_blocks_pdom, NULL, &n_blocks);
+
+ /* Memory for temporary information. */
+ tdi_list = XMALLOCNZ(tmp_dom_info, n_blocks);
+
+ /* 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(get_irg_end_block(irg), assign_tree_postdom_pre_order,
+ assign_tree_postdom_pre_order_max, &tree_pre_order);
+ }
+ current_ir_graph = rem;
+ add_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_POSTDOMINANCE);
+}
+
+void assure_postdoms(ir_graph *irg)
+{
+ if (! irg_has_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_POSTDOMINANCE))
+ compute_postdoms(irg);
+}
+
+void free_postdom(ir_graph *irg)
+{
+ /* Update graph state */
+ clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_POSTDOMINANCE);
}
projects / libfirm / blobdiff