2006-08-23 Jerry DeLisle <jvdelisle@gcc.gnu.org>

[pf3gnuchains/gcc-fork.git] / gcc / tree-phinodes.c

diff --git a/gcc/tree-phinodes.c b/gcc/tree-phinodes.c
index b7cfcb2..98b011f 100644 (file)
--- a/gcc/tree-phinodes.c
+++ b/gcc/tree-phinodes.c
@@ -392,7 +392,6 @@ add_phi_arg (tree phi, tree def, edge e)
     }
 
   SET_PHI_ARG_DEF (phi, e->dest_idx, def);
-  PHI_ARG_NONZERO (phi, e->dest_idx) = false;
 }
 
 /* Remove the Ith argument from PHI's argument list.  This routine
@@ -407,21 +406,25 @@ remove_phi_arg_num (tree phi, int i)
 
   gcc_assert (i < num_elem);
 
-  /* Delink the last item, which is being removed.  */
-  delink_imm_use (&(PHI_ARG_IMM_USE_NODE (phi, num_elem - 1)));
 
-  /* If we are not at the last element, switch the last element
-     with the element we want to delete.  */
+  /* Delink the item which is being removed.  */
+  delink_imm_use (&(PHI_ARG_IMM_USE_NODE (phi, i)));
+
+  /* If it is not the last element, move the last element
+     to the element we want to delete, resetting all the links. */
   if (i != num_elem - 1)
     {
-      SET_PHI_ARG_DEF (phi, i, PHI_ARG_DEF (phi, num_elem - 1));
-      PHI_ARG_NONZERO (phi, i) = PHI_ARG_NONZERO (phi, num_elem - 1);
+      use_operand_p old_p, new_p;
+      old_p = &PHI_ARG_IMM_USE_NODE (phi, num_elem - 1);
+      new_p = &PHI_ARG_IMM_USE_NODE (phi, i);
+      /* Set use on new node, and link into last element's place.  */
+      *(new_p->use) = *(old_p->use);
+      relink_imm_use (new_p, old_p);
     }
 
   /* Shrink the vector and return.  Note that we do not have to clear
-     PHI_ARG_DEF or PHI_ARG_NONZERO because the garbage collector will
-     not look at those elements beyond the first PHI_NUM_ARGS elements
-     of the array.  */
+     PHI_ARG_DEF because the garbage collector will not look at those
+     elements beyond the first PHI_NUM_ARGS elements of the array.  */
   PHI_NUM_ARGS (phi)--;
 }