#include "config.h"
#endif
+#ifdef HAVE_MALLOC_H
+#include <malloc.h>
+#endif
+#ifdef HAVE_ALLOCA_H
+#include <alloca.h>
+#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "irgraph_t.h" /* To access state field. */
#include "irnode_t.h"
#include "ircons_t.h"
+#include "array.h"
+#include "iredges.h"
#define get_dom_info(bl) (&(bl)->attr.block.dom)
return 0;
}
+/* Returns the smallest common dominator block of two nodes. */
+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;
+}
+
+/* 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)
+{
+ int n, j, i = 0, success;
+ ir_node **user_blocks, *dom_bl;
+ const ir_edge_t *edge;
+
+ assert(! is_Block(irn) && "WRONG USAGE of node_users_smallest_common_dominator");
+ assert(edges_activated(get_irn_irg(irn)) && "need edges activated");
+
+ n = get_irn_n_edges(irn);
+
+ /* get array to hold all block of the node users */
+ NEW_ARR_A(ir_node *, user_blocks, n);
+ foreach_out_edge(irn, edge) {
+ ir_node *src = get_edge_src_irn(edge);
+
+ if (is_Phi(src) && handle_phi) {
+ /* get the corresponding cfg predecessor block if phi handling requested */
+ j = get_edge_src_pos(edge);
+ assert(j >= 0 && "kaputt");
+ user_blocks[i++] = get_Block_cfgpred_block(get_nodes_block(src), j);
+ }
+ else
+ user_blocks[i++] = is_Block(src) ? src : get_nodes_block(src);
+ }
+
+ assert(i == n && "get_irn_n_edges probably broken");
+
+ /* in case of only one user: return the block of the user */
+ if (n == 1)
+ return user_blocks[0];
+
+ i = 0;
+ /* search the smallest block dominating all user blocks */
+ do {
+ dom_bl = node_smallest_common_dominator(user_blocks[i], user_blocks[i + 1]);
+ success = 1;
+
+ /* check if this block dominates all remaining blocks as well */
+ for (j = i + 2; j < n; j++) {
+ if (! block_dominates(dom_bl, user_blocks[j]))
+ success = 0;
+ }
+
+ if (success)
+ break;
+
+ /* inherit the dominator block of the first (i + 1) users */
+ user_blocks[++i] = dom_bl;
+ } while (i < n - 1);
+
+ assert(success && "no block found dominating all users");
+
+ 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)
{
/* The root of the dominator tree should be the End block. */
ir_node *root = get_irg_end_block(irg);
- assert(irg->pdom_state == dom_consistent
+ assert(irg->pdom_state == dom_consistent
&& "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
}
/*--------------------------------------------------------------------*/
-/* Building and Removing the dominator datastructure */
+/* Building and Removing the dominator data structure */
/*--------------------------------------------------------------------*/
-/**
- * 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(dom_info));
- set_Block_idom(bl, NULL);
- set_Block_dom_pre_num(bl, -1);
- set_Block_dom_depth(bl, -1);
-}
-
/**
* 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) ++;
+ int *n_blocks = (int *) env;
+ (*n_blocks) ++;
memset(get_pdom_info(bl), 0, sizeof(dom_info));
- set_Block_ipostdom(bl, NULL);
- set_Block_postdom_pre_num(bl, -1);
- set_Block_postdom_depth(bl, -1);
+ 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. */
/**
- * Walks Blocks along the out datastructure. If recursion started with
+ * 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_list, int *used, int n_blocks) {
tmp_dom_info *tdi;
int i;
- assert(get_irn_op(bl) == op_Block);
+ 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->semi = tdi;
+ tdi->label = tdi;
tdi->ancestor = NULL;
- tdi->bucket = NULL;
- tdi->parent = parent;
- tdi->block = bl;
+ 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);
+ 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);
}
}
* 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) {
+ tmp_dom_info *tdi_list, int* used, int n_blocks) {
tmp_dom_info *tdi;
int i;
- assert(get_irn_op(bl) == op_Block);
+ 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->block = bl;
/* Iterate */
- for(i = 0; i < get_Block_n_cfgpreds(bl); i++) {
+ 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);
+ 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);
+ }
}
}
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(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 (get_irn_op(pred) == op_Block) {
+ if (Block_not_block_visited(pred)) {
+ /* we found a endless loop */
+ dec_irg_block_visited(irg);
+ irg_block_walk(pred, pre, NULL, &n_blocks);
+ }
+ else
+ continue;
+ }
+ 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". */
current_ir_graph = irg;
/* Update graph state */
- assert(get_irg_phase_state(current_ir_graph) != phase_building);
- current_ir_graph->dom_state = dom_consistent;
+ assert(get_irg_phase_state(irg) != phase_building);
+ irg->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_dom, NULL, &n_blocks);
+ 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 datastructure. */
- if (current_ir_graph->outs_state != outs_consistent)
- compute_irg_outs(current_ir_graph);
+ /* 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(current_ir_graph);
- init_tmp_dom_info(get_irg_start_block(current_ir_graph), NULL, tdi_list, &used);
+ 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;
/* Step 2 */
irn_arity = get_irn_arity(w->block);
- for (j = 0; j < irn_arity; j++) {
+ for (j = 0; j < irn_arity; j++) {
ir_node *pred = get_Block_cfgpred_block(w->block, j);
tmp_dom_info *u;
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 ben implemented as linked lists. */
+ buckets can been implemented as linked lists. */
w->bucket = w->semi->bucket;
w->semi->bucket = w;
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++) {
+ 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);
- set_Block_dom_depth(w->block, get_Block_dom_depth(w->dom->block) + 1);
+
+ /* 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);
- current_ir_graph = rem;
/* Do a walk over the tree and assign the tree pre orders. */
{
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) {
current_ir_graph = irg;
/* Update graph state */
- assert(get_irg_phase_state(current_ir_graph) != phase_building);
- current_ir_graph->pdom_state = dom_consistent;
+ assert(get_irg_phase_state(irg) != phase_building);
+ irg->pdom_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_pdom, NULL, &n_blocks);
+ 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 datastructure. */
- if (current_ir_graph->outs_state != outs_consistent)
- compute_irg_outs(current_ir_graph);
+ /* 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(current_ir_graph);
- init_tmp_pdom_info(get_irg_end_block(current_ir_graph), NULL, tdi_list, &used);
+ 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"); */
tmp_dom_info *v;
/* Step 2 */
- irn_arity = get_Block_n_cfg_outs(w->block);
+ irn_arity = get_Block_n_cfg_outs_ka(w->block);
for (j = 0; j < irn_arity; j++) {
- ir_node *succ = get_Block_cfg_out(w->block, j);
+ ir_node *succ = get_Block_cfg_out_ka(w->block, j);
tmp_dom_info *u;
if (get_Block_postdom_pre_num (succ) == -1)
/* clean up */
free(tdi_list);
- current_ir_graph = rem;
/* Do a walk over the tree and assign the tree pre orders. */
{
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) {
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