* @brief Construct and access dominator / post dominator tree.
* @author Goetz Lindenmaier, Michael Beck, Rubino Geiss
* @date 2.2002
- * @version $Id$
*/
-#ifdef HAVE_CONFIG_H
#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"
/** Accessing the dominator and post dominator data structures **/
/*--------------------------------------------------------------------*/
-ir_node *get_Block_idom(const ir_node *bl) {
+ir_node *get_Block_idom(const ir_node *bl)
+{
assert(is_Block(bl));
if (get_Block_dom_depth(bl) == -1) {
/* This block is not reachable from Start */
- return new_Bad();
+ 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) {
+void set_Block_idom(ir_node *bl, ir_node *n)
+{
ir_dom_info *bli = get_dom_info(bl);
assert(is_Block(bl));
* If we don't set the root of the dominator tree
* Append bl to the dominates queue of n.
*/
- if(n != NULL) {
+ if (n != NULL) {
ir_dom_info *ni = get_dom_info(n);
bli->next = ni->first;
}
}
-ir_node *get_Block_ipostdom(const ir_node *bl) {
+ir_node *get_Block_ipostdom(const ir_node *bl)
+{
assert(is_Block(bl));
if (get_Block_postdom_depth(bl) == -1) {
/* This block is not reachable from Start */
- return new_Bad();
+ 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) {
+void set_Block_ipostdom(ir_node *bl, ir_node *n)
+{
ir_dom_info *bli = get_pdom_info(bl);
assert(is_Block(bl));
* If we don't set the root of the post dominator tree
* Append bl to the post dominates queue of n.
*/
- if(n != NULL) {
+ if (n != NULL) {
ir_dom_info *ni = get_pdom_info(n);
bli->next = ni->first;
}
}
-int get_Block_dom_pre_num(const ir_node *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) {
+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) {
+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) {
+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) {
+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) {
+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) {
+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) {
+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) {
+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) {
+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) {
+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) {
+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;
}
/* Check, if a block dominates another block. */
-int block_dominates(const ir_node *a, const ir_node *b) {
+int block_dominates(const ir_node *a, const ir_node *b)
+{
const ir_dom_info *ai, *bi;
if (is_Block(a) && is_Block(b)) {
}
/* Check, if a block strictly dominates another block. */
-int block_strictly_dominates(const ir_node *a, const ir_node *b) {
+int block_strictly_dominates(const ir_node *a, const ir_node *b)
+{
return (a != b) && block_dominates(a, b);
}
/* Returns the smallest common dominator block of two nodes. */
-ir_node *node_smallest_common_dominator(ir_node *a, ir_node *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;
}
/* Returns the smallest common dominator block of all users of a node. */
-ir_node *node_users_smallest_common_dominator(ir_node *irn, int handle_phi) {
+ir_node *node_users_smallest_common_dominator(ir_node *irn, int handle_phi)
+{
int n, j, i = 0, success;
ir_node **user_blocks, *dom_bl;
const ir_edge_t *edge;
/* Get the first node in the list of nodes dominated by a given block. */
-ir_node *get_Block_dominated_first(const ir_node *bl) {
+ir_node *get_Block_dominated_first(const ir_node *bl)
+{
assert(is_Block(bl));
return get_dom_info(bl)->first;
}
/* Get the next node in a list of nodes which are dominated by some
* other node. */
-ir_node *get_Block_dominated_next(const ir_node *bl) {
+ir_node *get_Block_dominated_next(const ir_node *bl)
+{
assert(is_Block(bl));
return get_dom_info(bl)->next;
}
/* Check, if a block post dominates another block. */
-int block_postdominates(const ir_node *a, const ir_node *b) {
+int block_postdominates(const ir_node *a, const ir_node *b)
+{
const ir_dom_info *ai, *bi;
if (is_Block(a) && is_Block(b)) {
}
/* Check, if a block strictly dominates another block. */
-int block_strictly_postdominates(const ir_node *a, const ir_node *b) {
+int block_strictly_postdominates(const ir_node *a, const ir_node *b)
+{
return (a != b) && block_postdominates(a, b);
}
/* Get the first node in the list of nodes post dominated by a given block. */
-ir_node *get_Block_postdominated_first(const ir_node *bl) {
+ir_node *get_Block_postdominated_first(const ir_node *bl)
+{
assert(is_Block(bl));
return get_pdom_info(bl)->first;
}
/* Get the next node in a list of nodes which are post dominated by some
* other node. */
-ir_node *get_Block_postdominated_next(const ir_node *bl) {
+ir_node *get_Block_postdominated_next(const ir_node *bl)
+{
assert(is_Block(bl));
return get_pdom_info(bl)->next;
}
{
ir_node *p;
- if(pre)
+ if (pre)
pre(bl, env);
dominates_for_each(bl, p) {
dom_tree_walk(p, pre, post, env);
}
- if(post)
+ if (post)
post(bl, env);
}
{
ir_node *p;
- if(pre)
+ if (pre)
pre(bl, env);
postdominates_for_each(bl, p) {
postdom_tree_walk(p, pre, post, env);
}
- if(post)
+ if (post)
post(bl, env);
}
/* The root of the dominator tree should be the Start block. */
ir_node *root = get_irg_start_block(irg);
- assert(irg->dom_state == dom_consistent
+ assert(is_irg_state(irg, IR_GRAPH_STATE_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
void postdom_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 End block. */
+ /* The root of the post dominator tree should be the End block. */
ir_node *root = get_irg_end_block(irg);
- assert(irg->pdom_state == dom_consistent
+ assert(is_irg_state(irg, IR_GRAPH_STATE_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
static void assign_tree_dom_pre_order(ir_node *bl, void *data)
{
- unsigned *num = data;
+ unsigned *num = (unsigned*) data;
ir_dom_info *bi = get_dom_info(bl);
bi->tree_pre_num = (*num)++;
unsigned children = 0;
(void) data;
- for(p = bi->first; p; p = get_dom_info(p)->next) {
+ 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++;
static void assign_tree_postdom_pre_order(ir_node *bl, void *data)
{
- unsigned *num = data;
+ unsigned *num = (unsigned*) data;
ir_dom_info *bi = get_pdom_info(bl);
bi->tree_pre_num = (*num)++;
unsigned children = 0;
(void) data;
- for(p = bi->first; p; p = get_pdom_info(p)->next) {
+ 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++;
/**
* count the number of blocks and clears the post dominance info
*/
-static void count_and_init_blocks_pdom(ir_node *bl, void *env) {
- if (is_Block(bl)) {
- 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);
- }
+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. */
* 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_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))
+ if (Block_block_visited(bl))
return;
mark_Block_block_visited(bl);
set_Block_dom_pre_num(bl, *used);
/* 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));
+ /* 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);
}
}
* 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_list, int* used, int n_blocks)
+{
tmp_dom_info *tdi;
int i;
}
}
-static void dom_compress(tmp_dom_info *v) {
+static void dom_compress(tmp_dom_info *v)
+{
assert (v->ancestor);
if (v->ancestor->ancestor) {
dom_compress (v->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) {
+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) {
+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) {
- if (is_Block(bl)) {
- 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);
- }
-}
+static void count_and_init_blocks_dom(ir_node *bl, void *env)
+{
+ int *n_blocks = (int *) env;
-/**
- * Initialize the dominance/postdominance construction:
- *
- * - count the number of blocks
- * - clear the dominance info
- *
- * @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) {
- int n_blocks = 0;
+ (*n_blocks) ++;
- /*
- * Normally one would use irg_block_walk_graph() here, however, this does NOT
- * guarantee that all UNREACHABLE blocks are visited.
- * This could led to wrong dominance info in those blocks, causing
- * the verifier to crash for instance.
- * So, we visit EVERY node to ensure the info is updated.
- */
- irg_walk_graph(irg, pre, NULL, &n_blocks);
- return 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);
}
-
-/* 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) {
+/* Computes the dominator trees. */
+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? */
/* 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);
+ 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);
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 *w = &tdi_list[i];
+ ir_node *block = w->block;
tmp_dom_info *v;
+ int irn_arity;
/* Step 2 */
- irn_arity = get_irn_arity(w->block);
+ irn_arity = get_irn_arity(block);
for (j = 0; j < irn_arity; j++) {
- ir_node *pred = get_Block_cfgpred_block(w->block, 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) == -1))
- continue; /* control-dead */
+ 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)]);
- if (u->semi < w->semi) w->semi = u->semi;
+ 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 (w->block == get_irg_end_block(irg)) {
+ if (block == get_irg_end_block(irg)) {
ir_node *end = get_irg_end(irg);
irn_arity = get_irn_arity(end);
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 */
+ 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;
+ if (u->semi < w->semi)
+ w->semi = u->semi;
}
}
if (! w->dom)
continue; /* control dead */
- if (w->dom != w->semi) w->dom = w->dom->dom;
+ 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 */
/* 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);
+ 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;
+ set_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_DOMINANCE);
}
-void assure_doms(ir_graph *irg) {
- if (get_irg_dom_state(irg) != dom_consistent)
+void assure_doms(ir_graph *irg)
+{
+ if (! is_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_DOMINANCE))
compute_doms(irg);
}
-void free_dom(ir_graph *irg) {
+void free_dom(ir_graph *irg)
+{
/* Update graph state */
assert(get_irg_phase_state(irg) != phase_building);
- irg->dom_state = dom_none;
+ clear_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_DOMINANCE);
/* 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) {
+/* Computes the post dominator trees. */
+void compute_postdoms(ir_graph *irg)
+{
ir_graph *rem = current_ir_graph;
int n_blocks, used, i, j;
tmp_dom_info *tdi_list;
/* 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);
+ 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);
tmp_dom_info *u;
if (get_Block_postdom_pre_num (succ) == -1)
- continue; /* endless-loop */
+ continue; /* endless-loop */
u = dom_eval (&tdi_list[get_Block_postdom_pre_num(succ)]);
if (u->semi < w->semi) w->semi = u->semi;
/* 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,
+ 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;
+ set_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_POSTDOMINANCE);
}
-void assure_postdoms(ir_graph *irg) {
- if (get_irg_postdom_state(irg) != dom_consistent)
+void assure_postdoms(ir_graph *irg)
+{
+ if (! is_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_POSTDOMINANCE))
compute_postdoms(irg);
}
-void free_postdom(ir_graph *irg) {
+void free_postdom(ir_graph *irg)
+{
/* Update graph state */
assert(get_irg_phase_state(irg) != phase_building);
- irg->pdom_state = dom_none;
+ clear_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_POSTDOMINANCE);
/* With the implementation right now there is nothing to free,
but better call it anyways... */