tree-phinodes.c (remove_all_phi_nodes_for): Speed up using a pointer to the last…

tree-phinodes.c (remove_all_phi_nodes_for): Speed up using a pointer to the last PHI node in the new PHI chain.

	* tree-phinodes.c (remove_all_phi_nodes_for): Speed up using a
	pointer to the last PHI node in the new PHI chain.

From-SVN: r90173

gcc/ChangeLog

+2004-11-06  Kazu Hirata  <kazu@cs.umass.edu>
+
+	* tree-phinodes.c (remove_all_phi_nodes_for): Speed up using a
+	pointer to the last PHI node in the new PHI chain.
+
 2004-11-06  Kaz Kojima  <kkojima@gcc.gnu.org>
 
 	* config/sh/sh.c (prepare_move_operands): Emit a use of r12

gcc/tree-phinodes.c

@@ -449,10 +449,10 @@ remove_all_phi_nodes_for (bitmap vars)
   FOR_EACH_BB (bb)
     {
       /* Build a new PHI list for BB without variables in VARS.  */
-      tree phi, new_phi_list, last_phi, next;
+      tree phi, new_phi_list, next;
+      tree *lastp = &new_phi_list;
 
-      last_phi = new_phi_list = NULL_TREE;
-      for (phi = phi_nodes (bb), next = NULL; phi; phi = next)
+      for (phi = phi_nodes (bb); phi; phi = next)
 	{
 	  tree var = SSA_NAME_VAR (PHI_RESULT (phi));
 
@@ -465,13 +465,8 @@ remove_all_phi_nodes_for (bitmap vars)
 		 Note that fact in PHI_REWRITTEN.  */
 	      PHI_REWRITTEN (phi) = 1;
 
-	      if (new_phi_list == NULL_TREE)
-		new_phi_list = last_phi = phi;
-	      else
-		{
-		  PHI_CHAIN (last_phi) = phi;
-		  last_phi = phi;
-		}
+	      *lastp = phi;
+	      lastp = &PHI_CHAIN (phi);
 	    }
 	  else
 	    {
@@ -483,8 +478,7 @@ remove_all_phi_nodes_for (bitmap vars)
 	}
 
       /* Make sure the last node in the new list has no successors.  */
-      if (last_phi)
-	PHI_CHAIN (last_phi) = NULL_TREE;
+      *lastp = NULL;
       bb_ann (bb)->phi_nodes = new_phi_list;
 
 #if defined ENABLE_CHECKING