re PR c/56113 (out of memory when compiling a function with many goto labels (50k > ))

2013-02-04  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/56113
	* tree-ssa-structalias.c (equiv_class_lookup, equiv_class_add):
	Merge into ...
	(equiv_class_lookup_or_add): ... this.
	(label_visit): Adjust and fix error in previous patch.
	(perform_var_substitution): Adjust.

From-SVN: r195707

gcc/ChangeLog

+2013-02-04  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/56113
+	* tree-ssa-structalias.c (equiv_class_lookup, equiv_class_add):
+	Merge into ...
+	(equiv_class_lookup_or_add): ... this.
+	(label_visit): Adjust and fix error in previous patch.
+	(perform_var_substitution): Adjust.
+
 2013-02-03  Oleg Endo  <olegendo@gcc.gnu.org>
 
 	* config/sh/divtab.c: Fix formatting and comments throughout the file.

gcc/tree-ssa-structalias.c

@@ -1908,54 +1908,29 @@ equiv_class_label_eq (const void *p1, const void *p2)
 	  && bitmap_equal_p (eql1->labels, eql2->labels));
 }
 
-/* Lookup a equivalence class in TABLE by the bitmap of LABELS it
-   contains.  Sets *REF_LABELS to the bitmap LABELS is equivalent to.  */
+/* Lookup a equivalence class in TABLE by the bitmap of LABELS with
+   hash HAS it contains.  Sets *REF_LABELS to the bitmap LABELS
+   is equivalent to.  */
 
-static unsigned int
-equiv_class_lookup (htab_t table, bitmap labels, bitmap *ref_labels)
+static equiv_class_label *
+equiv_class_lookup_or_add (htab_t table, bitmap labels)
 {
-  void **slot;
-  struct equiv_class_label ecl;
+  equiv_class_label **slot;
+  equiv_class_label ecl;
 
   ecl.labels = labels;
   ecl.hashcode = bitmap_hash (labels);
-
-  slot = htab_find_slot_with_hash (table, &ecl,
-				   ecl.hashcode, NO_INSERT);
-  if (!slot)
+  slot = (equiv_class_label **) htab_find_slot_with_hash (table, &ecl,
+							  ecl.hashcode, INSERT);
+  if (!*slot)
     {
-      if (ref_labels)
-	*ref_labels = NULL;
-      return 0;
+      *slot = XNEW (struct equiv_class_label);
+      (*slot)->labels = labels;
+      (*slot)->hashcode = ecl.hashcode;
+      (*slot)->equivalence_class = 0;
     }
-  else
-    {
-      equiv_class_label_t ec = (equiv_class_label_t) *slot;
-      if (ref_labels)
-	*ref_labels = ec->labels;
-      return ec->equivalence_class;
-    }
-}
-
-
-/* Add an equivalence class named EQUIVALENCE_CLASS with labels LABELS
-   to TABLE.  */
 
-static void
-equiv_class_add (htab_t table, unsigned int equivalence_class,
-		 bitmap labels)
-{
-  void **slot;
-  equiv_class_label_t ecl = XNEW (struct equiv_class_label);
-
-  ecl->labels = labels;
-  ecl->equivalence_class = equivalence_class;
-  ecl->hashcode = bitmap_hash (labels);
-
-  slot = htab_find_slot_with_hash (table, ecl,
-				   ecl->hashcode, INSERT);
-  gcc_assert (!*slot);
-  *slot = (void *) ecl;
+  return *slot;
 }
 
 /* Perform offline variable substitution.
@@ -2150,6 +2125,10 @@ label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
 	}
       bitmap_set_bit (graph->points_to[n], FIRST_REF_NODE + n);
       graph->pointer_label[n] = pointer_equiv_class++;
+      equiv_class_label_t ecl;
+      ecl = equiv_class_lookup_or_add (pointer_equiv_class_table,
+				       graph->points_to[n]);
+      ecl->equivalence_class = graph->pointer_label[n];
       return;
     }
 
@@ -2167,22 +2146,17 @@ label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
 
   if (!bitmap_empty_p (graph->points_to[n]))
     {
-      bitmap ref_points_to;
-      unsigned int label = equiv_class_lookup (pointer_equiv_class_table,
-					       graph->points_to[n],
-					       &ref_points_to);
-      if (!label)
-	{
-	  label = pointer_equiv_class++;
-	  equiv_class_add (pointer_equiv_class_table,
-			   label, graph->points_to[n]);
-	}
+      equiv_class_label_t ecl;
+      ecl = equiv_class_lookup_or_add (pointer_equiv_class_table,
+				       graph->points_to[n]);
+      if (ecl->equivalence_class == 0)
+	ecl->equivalence_class = pointer_equiv_class++;
       else
 	{
 	  BITMAP_FREE (graph->points_to[n]);
-	  graph->points_to[n] = ref_points_to;
+	  graph->points_to[n] = ecl->labels;
 	}
-      graph->pointer_label[n] = label;
+      graph->pointer_label[n] = ecl->equivalence_class;
     }
 }
 
@@ -2222,7 +2196,6 @@ perform_var_substitution (constraint_graph_t graph)
       bitmap pointed_by;
       bitmap_iterator bi;
       unsigned int j;
-      unsigned int label;
 
       if (!graph->pointed_by[i])
 	continue;
@@ -2240,14 +2213,10 @@ perform_var_substitution (constraint_graph_t graph)
 
       /* Look up the location equivalence label if one exists, or make
 	 one otherwise.  */
-      label = equiv_class_lookup (location_equiv_class_table,
-				  pointed_by, NULL);
-      if (label == 0)
-	{
-	  label = location_equiv_class++;
-	  equiv_class_add (location_equiv_class_table,
-			   label, pointed_by);
-	}
+      equiv_class_label_t ecl;
+      ecl = equiv_class_lookup_or_add (location_equiv_class_table, pointed_by);
+      if (ecl->equivalence_class == 0)
+	ecl->equivalence_class = location_equiv_class++;
       else
 	{
 	  if (dump_file && (dump_flags & TDF_DETAILS))
@@ -2255,7 +2224,7 @@ perform_var_substitution (constraint_graph_t graph)
 		     get_varinfo (i)->name);
 	  BITMAP_FREE (pointed_by);
 	}
-      graph->loc_label[i] = label;
+      graph->loc_label[i] = ecl->equivalence_class;
 
     }