extended functionality
[libfirm] / ir / ana / irdom.c
index 1bc8e47..ffb2c97 100644 (file)
 #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 "irnode_t.h"
+#include "ircons_t.h"
+
+#define get_dom_info(bl) (&(bl)->attr.block.dom)
 
-/**********************************************************************/
+
+/*--------------------------------------------------------------------*/
 /** Accessing the dominator data structures                          **/
-/**********************************************************************/
+/*--------------------------------------------------------------------*/
 
-ir_node *get_Block_idom(ir_node *bl) {
-  assert(get_irn_op(bl) == op_Block);
-  return bl->attr.block.dom.idom;
+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();
+  }
+  return get_dom_info(bl)->idom;
 }
 
 void set_Block_idom(ir_node *bl, ir_node *n) {
+       dom_info *bli = get_dom_info(bl);
+
   assert(get_irn_op(bl) == op_Block);
-  bl->attr.block.dom.idom = n;
+
+       /* 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) {
+               dom_info *ni = get_dom_info(n);
+
+               bli->next = ni->first;
+               ni->first = bl;
+       }
 }
 
-int get_Block_pre_num(ir_node *bl) {
+int get_Block_pre_num(const ir_node *bl) {
   assert(get_irn_op(bl) == op_Block);
   return bl->attr.block.dom.pre_num;
 }
@@ -45,7 +73,7 @@ void set_Block_pre_num(ir_node *bl, int num) {
   bl->attr.block.dom.pre_num = num;
 }
 
-int get_Block_dom_depth(ir_node *bl) {
+int get_Block_dom_depth(const ir_node *bl) {
   assert(get_irn_op(bl) == op_Block);
   return bl->attr.block.dom.dom_depth;
 }
@@ -55,30 +83,105 @@ void set_Block_dom_depth(ir_node *bl, int depth) {
   bl->attr.block.dom.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;
+}
+
+int block_dominates(const ir_node *a, const ir_node *b)
+{
+       const dom_info *ai, *bi;
 
+       assert(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;
+}
 
-/**********************************************************************/
-/** Building and Removing the dominator datasturcture                **/
-/**                                                                  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/** .**/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**  **/
-/**********************************************************************/
+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;
+}
+
+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 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 node. */
+       ir_node *root = get_irg_start_block(irg);
+
+  assert(irg->dom_state == dom_consistent
+                       && "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);
+}
+
+static void assign_tree_pre_order(ir_node *bl, void *data)
+{
+       unsigned *num = data;
+       dom_info *bi = get_dom_info(bl);
+
+       bi->tree_pre_num = (*num)++;
+}
+
+static void assign_tree_pre_order_max(ir_node *bl, void *data)
+{
+       dom_info *bi = get_dom_info(bl);
+       ir_node *p;
+       unsigned max = 0;
+       unsigned children = 0;
+
+       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);
+}
+
+/*--------------------------------------------------------------------*/
+/*  Building and Removing the dominator datastructure                 */
+/*--------------------------------------------------------------------*/
 
 static void count_and_init_blocks(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_pre_num(bl, -1);
   set_Block_dom_depth(bl, -1);
@@ -190,7 +293,7 @@ void compute_doms(ir_graph *irg) {
   irg_block_walk(get_irg_end(current_ir_graph), count_and_init_blocks, NULL, &n_blocks);
 
   /* Memory for temporary information. */
-  tdi_list = (tmp_dom_info *) calloc(n_blocks, sizeof(tmp_dom_info));
+  tdi_list = xcalloc(n_blocks, sizeof(tdi_list[0]));
 
   /* We need the out datastructure. */
   if (current_ir_graph->outs_state != outs_consistent)
@@ -215,10 +318,11 @@ void compute_doms(ir_graph *irg) {
     /* Step 2 */
     irn_arity = get_irn_arity(w->block);
     for (j = 0;  j < irn_arity;  j++) {
-      ir_node *pred = get_nodes_block(get_Block_cfgpred(w->block, 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(get_Block_cfgpred(w->block, j))) ||
+      if ((is_Bad(cf_op)) || (is_Bad(pred)) ||
          (get_Block_pre_num (pred) == -1))
        continue;       /* control-dead */
 
@@ -262,6 +366,13 @@ void compute_doms(ir_graph *irg) {
   /* clean up */
   /*  free(tdi_list); @@@ does not work !!?? */
   current_ir_graph = rem;
+
+       /* Do a walk over the tree and assign the tree pre orders. */
+       {
+               unsigned tree_pre_order = 0;
+               dom_tree_walk_irg(irg, assign_tree_pre_order,
+                               assign_tree_pre_order_max, &tree_pre_order);
+       }
 }
 
 void free_dom_and_peace(ir_graph *irg) {