re PR bootstrap/51725 (segfault in stage 3 when compiling gcc/opts.c for sparc64-linux)

	PR bootstrap/51725
	* cselib.c (add_mem_for_addr): Call canonical_cselib_val
	on mem_elt first.

From-SVN: r182819

gcc/ChangeLog

+2012-01-02  Jakub Jelinek  <jakub@redhat.com>
+
+	PR bootstrap/51725
+	* cselib.c (add_mem_for_addr): Call canonical_cselib_val
+	on mem_elt first.
+
 2012-01-02  Sandra Loosemore  <sandra@codesourcery.com>
 
 	* doc/invoke.texi (-flto and related options): Copy-edit.

gcc/cselib.c

 /* Common subexpression elimination library for GNU compiler.
    Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
-   Free Software Foundation, Inc.
+   1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011,
+   2012 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -1264,6 +1264,8 @@ add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x)
 {
   struct elt_loc_list *l;
 
+  mem_elt = canonical_cselib_val (mem_elt);
+
   /* Avoid duplicates.  */
   for (l = mem_elt->locs; l; l = l->next)
     if (MEM_P (l->loc)