ira-costs.c (find_costs_and_classes): Initialize cost_classes later to make sure…

ira-costs.c (find_costs_and_classes): Initialize cost_classes later to make sure not to dereference a NULL...

	* ira-costs.c (find_costs_and_classes): Initialize cost_classes later
	to make sure not to dereference a NULL cost_classes_ptr pointer.

From-SVN: r249426

gcc/ChangeLog

+2017-06-20  Jakub Jelinek  <jakub@redhat.com>
+
+	* ira-costs.c (find_costs_and_classes): Initialize cost_classes later
+	to make sure not to dereference a NULL cost_classes_ptr pointer.
+
 2017-06-20  Carl Love  <cel@us.ibm.com>
 
 	* config/rs6000/rs6000-c.c (altivec_overloaded_builtins): Add

gcc/ira-costs.c

@@ -1744,7 +1744,7 @@ find_costs_and_classes (FILE *dump_file)
 	  int best_cost, allocno_cost;
 	  enum reg_class best, alt_class;
 	  cost_classes_t cost_classes_ptr = regno_cost_classes[i];
-	  enum reg_class *cost_classes = cost_classes_ptr->classes;
+	  enum reg_class *cost_classes;
 	  int *i_costs = temp_costs->cost;
 	  int i_mem_cost;
 	  int equiv_savings = regno_equiv_gains[i];
@@ -1755,6 +1755,7 @@ find_costs_and_classes (FILE *dump_file)
 		continue;
 	      memcpy (temp_costs, COSTS (costs, i), struct_costs_size);
 	      i_mem_cost = temp_costs->mem_cost;
+	      cost_classes = cost_classes_ptr->classes;
 	    }
 	  else
 	    {
@@ -1762,6 +1763,7 @@ find_costs_and_classes (FILE *dump_file)
 		continue;
 	      memset (temp_costs, 0, struct_costs_size);
 	      i_mem_cost = 0;
+	      cost_classes = cost_classes_ptr->classes;
 	      /* Find cost of all allocnos with the same regno.  */
 	      for (a = ira_regno_allocno_map[i];
 		   a != NULL;