--- a/gcc/alias.c	Thu Sep 24 13:06:16 2009 +0900
+++ b/gcc/alias.c	Thu Sep 24 13:21:57 2009 +0900
@@ -1438,15 +1438,16 @@
 	  return x;
       return 0;
 
+    case LO_SUM:
+      /* The standard form is (lo_sum reg sym) so look only at the
+         second operand.  */
+      return find_base_term (XEXP (x, 1));
+
     case CONST:
       x = XEXP (x, 0);
       if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS)
 	return 0;
       /* Fall through.  */
-    case LO_SUM:
-      /* The standard form is (lo_sum reg sym) so look only at the
-         second operand.  */
-      return find_base_term (XEXP (x, 1));
     case PLUS:
     case MINUS:
       {
@@ -2250,14 +2251,13 @@
    Variant of true_dependence which assumes MEM has already been
    canonicalized (hence we no longer do that here).
    The mem_addr argument has been added, since true_dependence computed
-   this value prior to canonicalizing.  */
+   this value prior to canonicalizing.
+   If x_addr is non-NULL, it is used in preference of XEXP (x, 0).  */
 
 int
 canon_true_dependence (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr,
-		       const_rtx x, bool (*varies) (const_rtx, bool))
+		       const_rtx x, rtx x_addr, bool (*varies) (const_rtx, bool))
 {
-  rtx x_addr;
-
   if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
     return 1;
 
@@ -2283,7 +2283,8 @@
   if (nonoverlapping_memrefs_p (x, mem))
     return 0;
 
-  x_addr = get_addr (XEXP (x, 0));
+  if (! x_addr)
+    x_addr = get_addr (XEXP (x, 0));
 
   if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
     return 0;